Montag, 28.9.: Anreise und gemeinsames Abendessen um 18:30

Freitag, 2.10.: gemeinsames Frühstück und Abreise

Zeit Dienstag, 29.9. Mittwoch, 30.9. Donnerstag, 1.10.

7:00-8:30

08:30 Begrüßung V12, Strack V21, Streich

08:50 V1, Heise V13, Schwalenberg V22, Schwarzbach

09:10 V2, Diaz V14, Lippert V23, Kütter

09:30 V3, Häuserer V15, Hölz V24, Moorkamp

09:50 V4, Meqbel V16, Bücker V25, Roux

10:10-10:30

10:30 V5, Bhatt V17, Miensopust V26, Yogeshwar

10:50 V6, Streich V18, Weckmann V27, Abdelfettah

11:10 V7, Hanstein V19, Worzewski V28, Gurk

11:30 V8, Kalscheuer V20, Adao V29, Hendricks

11:50 V9, Hoerdt Vorstellung Wanderung V30, Rabenstein

12:30-14:00

14:00 Hördt, V10, Pedersen V31, Stoll

14:20 V11, Pedersen V32, Virgil

14:45 - 16:00 Posterkurzvorstellungen Posterkurzvorstellungen

16:00-16:20 Kaffee Kaffee

16:00-18:00 Poster Poster

18:30-19:30

19:30-21:00 Diskussionsbeiträge Mitgliederversammlung DiskussionsbeiträgePW1, Hanstein (für Alle!) D3, TezkanPW2, Tezkan D4, WeckmannPW3, Spitzer D5, Gang

PW4, Pek D1, TezkanPW5, Weckmann D2, Ritter

PW6, Hördt

P1, Kenkel P21, HansteinP2, Bairlein P22, KirchnerP3, Rödder P23, WeißflogP4, Treichel P24, Lehmann-HornP5, von Papen P25, AfanasjewP6, Widodo P26, RenP7, Bosch P27, MeqbelP8, Neska P28, HeinckeP9, Przyklenk P29, MandolesiP10, Ehmann P30, Chen, X.P11, Hofmeister P31, CervP12, Steuer P32, SchäferP13, Schaumann P33, EydamP14, Chen, J. P34, KapinosP15, Tietze P35, MunozP16, Tripaldi P36, KalberkampP17, Nube P37, MütschardP18, Becken P38, BrändleinP19, Bhatt P39, Le PapeP20 P40, Ritter

Abendessen

Wanderung

Posterbeiträge / Kurzvorstellung

23. Kolloquium Elektromagnetische Tiefenforschung, Heimvolkshochschule Seddiner See

Frühstück

28. September bis 2. Oktober 2009

Kaffee

Mittagessen

ID Name First Name co-authors Type Title

D01 Tezkan Bülent D Geophysikalischer Gerätepool Potsdam: Bedarf der Arbeitsgruppe?

D02 Ritter Oliver D Permanente Remote Referenzstationen in Deutschland – eine konzertierte Aktion des AK EMTF?

D03 Tezkan Bülent D Interpretation der magnetotellurischen Anisotropie: Ansätze nach Ulrich Schmucker

D04 Weckmann Ute D What you always wanted to know about…

D05 Yu Gang T. Hanstein, Z. X He, I. M. Þorbergsdóttir, K.-

M. Strack, and H. Tulinius

D Geothermal exploration using MT and gravity techniques at Szentlőrinc area in Hungary

P01 Kenkel Johannes Hördt, A. P Zweidimensionale SIP-Modellierung mit anisotroper Leitfähigkeit

P02 Bairlein Katharina Hördt, A., Kenkel, J. P Untersuchungen zur Genauigkeit der Spektralen Induzierten Polarisation

P03 Rödder Annika Tezkan, B., P SHOTEM Messungen im Arava Valley, Dead-Sea Transform Verwerfung, Jordanien

-Vorbereitung der Wiederholungsmessungen im Dezember 2009 -

P04 Treichel Andrea Steuer, A., Blindow, N. P Transienten Elektromagnetik und Geoelektrik zur hydrogeologischen Erkundung in der Haseldorfer Marsch

P05 von Papen Michael P On the anaysis of LOTEM time series from Israel and the preliminary 1D inversion of data

P06 Widodo Widodo Gurk, M., Tezkan, B. P Site Effect Assessment in The Mygdonian Basin (EUROSEISTEST area, Northern Greece) Using TEM and RMT

Soundings

P07 Bosch Frank Gurk, M. P Hidden Mine Shaft Detection with Remote Radio Transmitter Electromagnetic and Self-Potential Method

P08 Neska Anne P Subsurface conductivity obtained from DC railway signal propagation with a dipole model

P09 Przyklenk Anita Hördt, A. P Übergangsimpedanzen von Elektroden zur Bestimmung elektrischer Widerstände von Monden und Kometen

P10 Ehmann Sebastian Hördt, A., Virgil, C., Leven, M., Steveling, E. P Störkörperdetektion mittels 3-Komponenten-Magnetometerdaten

P11 Hofmeister Paul Grosse, J., Hördt, A., Glassmeier, K.H. P Räumlich hochauflösende Vermessung magnetischer Anomalien mit einem unbemannten Luftschiff

P12 Steuer Annika Siemon, B., Grinat, M. P Die deutsche Nordseeküste im Fokus von aero-elektromagnetischen Untersuchungen:

I. Erkundung der Süßwasserlinsen von Borkum

P13 Schaumann Gerlinde Steuer, A., Siemon, B., Wiederhold, H. P Die deutsche Nordseeküste im Fokus von aero-elektromagnetischen Untersuchungen - II. Elbemündung und

Langeoog mit Wattenmeer

P14 Chen Jin Jegen-Kulcsar, M. P The Empirical Mode Decomposition and Spectra based on Direct Quadrature in MT data processing

P15 Tietze Kristina Ritter, O., Weckmann, U. P Substitute models for static shift (in 2D)

P16 Tripaldi S. Siniscalchi, A., Spitzer, K. P A method to determine the magnetotelluric static shift from DC resistivity measurements in practice

P17 Nube Andreas Weckmann, U., Ritter, O., Chen, X., Deacon,

J., MacLennan, S., Moodley, L., DeWit, M.,

Willkommen, G., Barth, R., Streich, R.,

Tietze, K.

P Magnetotelluric measurements across the southern Barberton greenstone belt: Data analysis

P18 Becken Michael Streich, R., Ritter, O. P Aufbau einer Controlled Source Magnetotellurik am GFZ

P19 Bhatt K. Mangal Hördt, A., Hanstein, T. P Analysis of seafloor marine EM data with respect to motion-induced noise

P21 Hanstein Tilman P TEM with anomalous diffusion in fractional conductive media

P22 Kirchner Judith Börner, R.-U., Spitzer, K. P 1D – Simulation von Bohrlochtransientelektromagnetik zur CO2 – Sequestrierung

P23 Weißflog Julia Börner, R.-U., Spitzer, K. P Die Felder des horizontalen elektrischen Dipols im geschichteten Halbraum

P24 Lehmann-Horn Jochen P Hybrid electromagnetic modelling of large surface loops on rugged terrain

P25 Afanasjew Martin Börner, R.-U., Eiermann, M., Ernst, O.G.,

Spitzer, K.

P Advances in the Numerical Solution of the 3-D TEM Forward Problem

P26 Ren Zhengyong Kalscheuer, T., Maurer, H.R. P Edge-based boundary element method for 3D RMT modelling incorporating surface

topography - a theoretical study

P27 Meqbel Naser Ritter, O., Egbert, G., Siripunvaraporn, W. P A scheme to invert magnetotelluric data in two and three dimensions on parallel computer architectures:

Concepts and applications

P28 Heincke Björn Henning Jegen, M., Moorkamp, M., P Comparison of different coupling strategies in joint inversions

P29 Mandolesi Eric Jones, A. G., Roux, E., Lebedev, S. P Common Structure in Different Physical Properties: Electrical Conductivity and Wave S-Velocity

P30 Chen Xiaoming Weckmann, U., Tietze, K., P Working towards modeling of phases over 90° with 2D anisotropic inversion

P31 Cerv Vaclav Kovacikova, S., Menvielle, M., Pek, J. P Thin sheet conductance models from geomagnetic induction data: Study of induction

anomalies at the transition from the Bohemian Massif to the West Carpathians

P32 Schäfer Anja Brasse, H., Houpt, L., Weichelt, D. P Magnetotelluric investigation of the Sorgenfrei-Tornquist Zone and the NE German Basin.

P33 Eydam Diane Brasse, H., P Imaging fluids and melts in the crust and upper mantle of the Bolivian Orocline, Central Andes (18°S) –

Interpretation of magnetotelluric data

P34 Kapinos Gerhard Brasse, H., P Results of an amphibious magnetotelluric experiment at the South-Central

Chilean continental margin

P35 Muñoz Gerard Bauer, K., Moeck. I., Ritter, O. P Combining magnetotelluric and seismic models for exploration of the Groß Schönebeck

geothermal site: a statistical approach

P36 Kalberkamp Ulrich P Magnetotelluric measurements to explore for deeper structures of the Tendaho geothermal field, Afar, NE

Ethiopia

P37 Mütschard Lutz Brasse, H. P Magnetotellurics at the Central American margin in Costa Rica and Nicaragua

P38 Brändlein Dirk Ritter, O., Krings, T., Weckmann, U. P New Data from a permanent array of magnetotelluric stations located at the South

American subduction zone in Northern Chile

P39 Le Pape Florian Jones, A. G., Vozar, J., INDEPTH MT Team P Evolution of the crust and upper mantle structure beneath the Kunlun Shan in Northern Tibet from INDEPTH

magnetotelluric data

P40 Ritter Oliver Rybin, A., Muñoz, G., Batalev, V. P Magnetotelluric data from the Tien Shan and Pamir continental collision zones, Central Asia.

PW1 Hanstein Tilman PW

PW2 Tezkan Bülent PW 28 Jahre mit Peter Weidelt: Von der Betreuung der Diplomarbeit bis zu gemeinsamen Forschungsaufenthalten in

Indien

PW3 Spitzer Klaus PW Konjugierte Gradienten

PW4 Pek Josef PW Peter Weidelt's Anisotropy Studies

PW5 Weckmann Ute PW A direct inversion? Application of Propagation Number Analysis - in remembrance of Peter Weidelt

PW6 Hördt Andreas PW

V01 Heise Wiebke Caldwell, T.G., Bibby, H.M., Bennie, S.L. O 3-D conductivity image of the deep magma sources of the Taupo Volcanic Zone, New Zealand

V02 Diaz Daniel Brasse, H., Banaszak, M. O Magnetotelluric study of Lascar volcano, Central Andes

V03 Häuserer Michael Junge, A. O Dominant phase split in MT data from the Western branch of the East African Rift in Uganda explained by a

preliminary three dimensional model with an electrically anisotropic lithosphere

V04 Meqbel Naser Ritter, O., Weckmann, U., Becken, M.,

Munoz, G.

O The electrical conductivity structure of the Dead Sea Basin derived from 2D and 3D inversion of magnetotelluric

data

V05 Bhatt K. Mangal Hördt, A., Weidelt, P., Hanstein, T. O Motionally Induced Electromagnetic Field within the Ocean

V06 Streich Rita O ”Air waves” in marine controlled-source electromagnetics

- The potential of Peter Weidelt’s work

V07 Hanstein Tilman Löhken, J., Löhken, I., Mollidor, L., Qian, W.,

Ellingsrud, S., Yu, G., Strack, K.M.

O From LOTEM to Marine tCSEM™ for hydrocarbon exploration: concepts and realization

V08 Kalscheuer Thomas Garcia, M., Meqbel, N., Pedersen, L.B. O Smoothness-constrained model error and resolution estimates from the inversion of direct current resistivity and

radiomagnetotelluric data

V09 Hördt Andreas Weidelt, P., Przyklenk, A. O Die Übergangsimpedanz einer kapazitiv angekoppelten Elektrode

V10 Hördt Andreas PW Nachruf Peter Weidelt

V11 Pedersen Laust B. O Some remarks on Peter Weidelt’s influence on Scandinavian EM research

V12 Strack Kurt Hanstein, T., Yu, G. O Full Field EM Monitoring

V13 Schwalenberg Katrin Engels, M., Deppe, J., Jegen, M. and the

New Vents Working Group

O Marine CSEM activities at BGR:

- Gas hydrate studies in New Zealand

- Instrument developments: A new bottom-towed multi-receiver system

V14 Lippert Klaus Tezkan, B., Bergers, R., Gurk, M., v.Papen,

M., Yogeshwar, P.

O Erkundung eines Aquifers unter dem Mittelmeer vor der israelischen Küsten mit LOTEM.

V15 Hölz Sebastian O Harmonic oscillations in EM-signals measured on the "North Alex" mud-volcano

V16 Bücker Matthias Kenkel, J., Hördt, A., Hanstein, T. O Einfluss von Bathymetrie auf marine CSEM Messungen im Zeitbereich

V17 Miensopust Marion et al., O Magnetotelluric study in northeastern Botswana

V18 Weckmann Ute Becken, M., Ritter, O., de Wit, M. O Imaging the Kaapvaal Craton boundary, South Africa, using Magnetotellurics

V19 Worzewski Tamara Jegen, M., Kapionos, G., Brasse, H. O Using Amphibious Magnetotellurics to image Hydration and Dehydration of the Costa Rican Subduction Zone and

to demonstrate the bathymetric effect on marine data

V20 Adão Filipe Heise, W. O 3-D model study to determine the mantle conductivity of the SW Iberian Peninsular using

phase tensor methods

V21 Streich Rita Becken, M., O EM fields generated by finite-length wire sources in 1D media: comparison with point dipole solutions

V22 Schwarzbach Christoph Börner, R.U., Spitzer, K. O A 3-D Model Study for Marine EM Using Vector Finite Elements

V23 Kütter S. Franke-Börner, A., Börner, R.-U., Spitzer, K. O Three-dimensional FE simulation of magnetotelluric fields using digital terrain models exemplified for Stromboli

volcano

V24 Moorkamp Max Jegen, M. Hobbs, R. W., Roberts, A.,

Heincke, B.

O Towards 3D joint inversion of full tensor gravity, magnetotelluric and seismic refraction data

V25 Roux Estelle Moorkamp, M., Jones, A. G., O Joint Inversion of Magnetotelluric and Surface Wave Data in an Anisotropic Earth

V26 Yogeshwar Pritam Tezkan, B., Israil, M. O Grundwasserkontamination bei Roorkee/Indien:

2D Joint Inversion von Radiomagnetotellurik und Gleichstromgeoelektrik Daten

V27 Abdelfettah Yassine Tarits, P., Hautot, S., Maia, M., and Tiercelin,

J-J.

O Improvement of the geophysical imaging by MT and Gravity joint inversion: Application to Turkana region,

Northern Kenya

V28 Gurk Marcus O Integrated nonseismic geophysical studies to assess the site effect of the EUROSEISTEST area in Northern Greece

(IGSEA)

V29 Hendricks Stefan Haas, C., Rabenstein, L., Lobach, J. O Airborne EM sea ice thickness sounding: Forward modelling and hardware developments

V30 Rabenstein Lasse Hendricks, S., Haas, C., Lobach, J. O Development and test of a fixed wing AEM sea ice thickness sounder

V31 Stoll Johannes O Orientation Tracking Method for mobile geophysical measuring systems

V32 Virgil Christopher Hördt, A., Leven, M., Steveling, E. O Durchführung und Auswertung von dreikomponentigen Bohrlochmagnetometermessungen

ID Name First Name co-authors Type Title

V27 Abdelfettah Yassine Tarits, P., Hautot, S., Maia, M., and Tiercelin,

J-J.

O Improvement of the geophysical imaging by MT and Gravity joint inversion: Application to Turkana region,

Northern Kenya

V20 Adão Filipe Heise, W. O 3-D model study to determine the mantle conductivity of the SW Iberian Peninsular using

phase tensor methods

P25 Afanasjew Martin Börner, R.-U., Eiermann, M., Ernst, O.G.,

Spitzer, K.

P Advances in the Numerical Solution of the 3-D TEM Forward Problem

P02 Bairlein Katharina Hördt, A., Kenkel, J. P Untersuchungen zur Genauigkeit der Spektralen Induzierten Polarisation

P18 Becken Michael Streich, R., Ritter, O. P Aufbau einer Controlled Source Magnetotellurik am GFZ

P19 Bhatt K. Mangal Hördt, A., Hanstein, T. P Analysis of seafloor marine EM data with respect to motion-induced noise

V05 Bhatt K. Mangal Hördt, A., Weidelt, P., Hanstein, T. O Motionally Induced Electromagnetic Field within the Ocean

P07 Bosch Frank Gurk, M. P Hidden Mine Shaft Detection with Remote Radio Transmitter Electromagnetic and Self-Potential Method

P38 Brändlein Dirk Ritter, O., Krings, T., Weckmann, U. P New Data from a permanent array of magnetotelluric stations located at the South

American subduction zone in Northern Chile

V16 Bücker Matthias Kenkel, J., Hördt, A., Hanstein, T. O Einfluss von Bathymetrie auf marine CSEM Messungen im Zeitbereich

P31 Cerv Vaclav Kovacikova, S., Menvielle, M., Pek, J. P Thin sheet conductance models from geomagnetic induction data: Study of induction

anomalies at the transition from the Bohemian Massif to the West Carpathians

P14 Chen Jin Jegen-Kulcsar, M. P The Empirical Mode Decomposition and Spectra based on Direct Quadrature in MT data processing

P30 Chen Xiaoming Weckmann, U., Tietze, K. P Working towards modeling of phases over 90° with 2D anisotropic inversion

V02 Diaz Daniel Brasse, H., Banaszak, M. O Magnetotelluric study of Lascar volcano, Central Andes

P10 Ehmann Sebastian Hördt, A., Virgil, C., Leven, M., Steveling, E. P Störkörperdetektion mittels 3-Komponenten-Magnetometerdaten

P33 Eydam Diane Brasse, H., P Imaging fluids and melts in the crust and upper mantle of the Bolivian Orocline, Central Andes (18°S) –

Interpretation of magnetotelluric data

V28 Gurk Marcus O Integrated nonseismic geophysical studies to assess the site effect of the EUROSEISTEST area in Northern Greece

(IGSEA)

P21 Hanstein Tilman P TEM with anomalous diffusion in fractional conductive media

PW1 Hanstein Tilman PW

V07 Hanstein Tilman Löhken, J., Löhken, I., Mollidor, L., Qian, W.,

Ellingsrud, S., Yu, G., Strack, K.M.

O From LOTEM to Marine tCSEM™ for hydrocarbon exploration: concepts and realization

V03 Häuserer Michael Junge, A. O Dominant phase split in MT data from the Western branch of the East African Rift in Uganda explained by a

preliminary three dimensional model with an electrically anisotropic lithosphere

P28 Heincke Björn Henning Jegen, M., Moorkamp, M., P Comparison of different coupling strategies in joint inversions

V01 Heise Wiebke Caldwell, T.G., Bibby, H.M., Bennie, S.L. O 3-D conductivity image of the deep magma sources of the Taupo Volcanic Zone, New Zealand

V29 Hendricks Stefan Haas, C., Rabenstein, L., Lobach, J. O Airborne EM sea ice thickness sounding: Forward modelling and hardware developments

P11 Hofmeister Paul Grosse, J., Hördt, A., Glassmeier, K.H. P Räumlich hochauflösende Vermessung magnetischer Anomalien mit einem unbemannten Luftschiff

V15 Hölz Sebastian O Harmonic oscillations in EM-signals measured on the "North Alex" mud-volcano

PW6 Hördt Andreas PW

V09 Hördt Andreas Weidelt, P., Przyklenk, A. O Die Übergangsimpedanz einer kapazitiv angekoppelten Elektrode

V10 Hördt Andreas PW Nachruf Peter Weidelt

P36 Kalberkamp Ulrich P Magnetotelluric measurements to explore for deeper structures of the Tendaho geothermal field, Afar, NE

Ethiopia

V08 Kalscheuer Thomas Garcia, M., Meqbel, N., Pedersen, L.B. O Smoothness-constrained model error and resolution estimates from the inversion of direct current resistivity and

radiomagnetotelluric data

P34 Kapinos Gerhard Brasse, H., P Results of an amphibious magnetotelluric experiment at the South-Central

Chilean continental margin

P01 Kenkel Johannes Hördt, A. P Zweidimensionale SIP-Modellierung mit anisotroper Leitfähigkeit

P22 Kirchner Judith Börner, R.-U., Spitzer, K. P 1D – Simulation von Bohrlochtransientelektromagnetik zur CO2 – Sequestrierung

V23 Kütter S. Franke-Börner, A., Börner, R.-U., Spitzer, K. O Three-dimensional FE simulation of magnetotelluric fields using digital terrain models exemplified for Stromboli

volcano

P39 Le Pape Florian Jones, A. G., Vozar, J., INDEPTH MT Team P Evolution of the crust and upper mantle structure beneath the Kunlun Shan in Northern Tibet from INDEPTH

magnetotelluric data

P24 Lehmann-Horn Jochen P Hybrid electromagnetic modelling of large surface loops on rugged terrain

V14 Lippert Klaus Tezkan, B., Bergers, R., Gurk, M., v.Papen,

M., Yogeshwar, P.

O Erkundung eines Aquifers unter dem Mittelmeer vor der israelischen Küsten mit LOTEM.

P29 Mandolesi Eric Jones, A. G., Roux, E., Lebedev, S. P Common Structure in Different Physical Properties: Electrical Conductivity and Wave S-Velocity

P27 Meqbel Naser Ritter, O., Egbert, G., Siripunvaraporn, W. P A scheme to invert magnetotelluric data in two and three dimensions on parallel computer architectures:

Concepts and applications

V04 Meqbel Naser Ritter, O., Weckmann, U., Becken, M.,

Munoz, G.

O The electrical conductivity structure of the Dead Sea Basin derived from 2D and 3D inversion of magnetotelluric

data

V17 Miensopust Marion et al., O Magnetotelluric study in northeastern Botswana

V24 Moorkamp Max Jegen, M. Hobbs, R. W., Roberts, A.,

Heincke, B.

O Towards 3D joint inversion of full tensor gravity, magnetotelluric and seismic refraction data

P35 Muñoz Gerard Bauer, K., Moeck. I., Ritter, O. P Combining magnetotelluric and seismic models for exploration of the Groß Schönebeck

geothermal site: a statistical approach

P37 Mütschard Lutz Brasse, H. P Magnetotellurics at the Central American margin in Costa Rica and Nicaragua

P08 Neska Anne P Subsurface conductivity obtained from DC railway signal propagation with a dipole model

P17 Nube Andreas et al., P Magnetotelluric measurements across the southern Barberton greenstone belt: Data analysis

V11 Pedersen Laust B. O Some remarks on Peter Weidelt’s influence on Scandinavian EM research

PW4 Pek Josef PW Peter Weidelt's Anisotropy Studies

P09 Przyklenk Anita Hördt, A. P Übergangsimpedanzen von Elektroden zur Bestimmung elektrischer Widerstände von Monden und Kometen

V30 Rabenstein Lasse Hendricks, S., Haas, C., Lobach, J. O Development and test of a fixed wing AEM sea ice thickness sounder

P26 Ren Zhengyong Kalscheuer, T., Maurer, H.R. P Edge-based boundary element method for 3D RMT modelling incorporating surface

topography - a theoretical study

D02 Ritter Oliver D Permanente Remote Referenzstationen in Deutschland – eine konzertierte Aktion des AK EMTF?

P40 Ritter Oliver Rybin, A., Muñoz, G., Batalev, V. P Magnetotelluric data from the Tien Shan and Pamir continental collision zones, Central Asia.

P03 Rödder Annika Tezkan, B., P SHOTEM Messungen im Arava Valley, Dead-Sea Transform Verwerfung, Jordanien

-Vorbereitung der Wiederholungsmessungen im Dezember 2009 -

V25 Roux Estelle Moorkamp, M., Jones, A. G., O Joint Inversion of Magnetotelluric and Surface Wave Data in an Anisotropic Earth

P32 Schäfer Anja Brasse, H., Houpt, L., Weichelt, D. P Magnetotelluric investigation of the Sorgenfrei-Tornquist Zone and the NE German Basin.

P13 Schaumann Gerlinde Steuer, A., Siemon, B., Wiederhold, H. P Die deutsche Nordseeküste im Fokus von aero-elektromagnetischen Untersuchungen - II. Elbemündung und

Langeoog mit Wattenmeer

V13 Schwalenberg Katrin Engels, M., Deppe, J., Jegen, M. and the New

Vents Working Group

O Marine CSEM activities at BGR:

- Gas hydrate studies in New Zealand

- Instrument developments: A new bottom-towed multi-receiver system

V22 Schwarzbach Christoph Börner, R.U., Spitzer, K. O A 3-D Model Study for Marine EM Using Vector Finite Elements

PW3 Spitzer Klaus PW Konjugierte Gradienten

P12 Steuer Annika Siemon, B., Grinat, M. P Die deutsche Nordseeküste im Fokus von aero-elektromagnetischen Untersuchungen:

I. Erkundung der Süßwasserlinsen von BorkumV31 Stoll Johannes O Orientation Tracking Method for mobile geophysical measuring systems

V12 Strack Kurt Hanstein, T., Yu, G. O Full Field EM Monitoring

V06 Streich Rita O ”Air waves” in marine controlled-source electromagnetics

- The potential of Peter Weidelt’s workV21 Streich Rita Becken, M., O EM fields generated by finite-length wire sources in 1D media: comparison with point dipole solutions

D01 Tezkan Bülent D Geophysikalischer Gerätepool Potsdam: Bedarf der Arbeitsgruppe?

D03 Tezkan Bülent D Interpretation der magnetotellurischen Anisotropie: Ansätze nach Ulrich Schmucker

PW2 Tezkan Bülent PW 28 Jahre mit Peter Weidelt: Von der Betreuung der Diplomarbeit bis zu gemeinsamen Forschungsaufenthalten in

Indien

P15 Tietze Kristina Ritter, O., Weckmann, U. P Substitute models for static shift (in 2D)

P04 Treichel Andrea Steuer, A., Blindow, N. P Transienten Elektromagnetik und Geoelektrik zur hydrogeologischen Erkundung in der Haseldorfer Marsch

P16 Tripaldi S. Siniscalchi, A., Spitzer, K. P A method to determine the magnetotelluric static shift from DC resistivity measurements in practice

V32 Virgil Christopher Hördt, A., Leven, M., Steveling, E. O Durchführung und Auswertung von dreikomponentigen Bohrlochmagnetometermessungen

P05 von Papen Michael P On the anaysis of LOTEM time series from Israel and the preliminary 1D inversion of data

D04 Weckmann Ute D What you always wanted to know about…

PW5 Weckmann Ute PW A direct inversion? Application of Propagation Number Analysis - in remembrance of Peter

Weidelt

V18 Weckmann Ute Becken, M., Ritter, O., de Wit, M. O Imaging the Kaapvaal Craton boundary, South Africa, using Magnetotellurics

P23 Weißflog Julia Börner, R.-U., Spitzer, K. P Die Felder des horizontalen elektrischen Dipols im geschichteten Halbraum

P06 Widodo Widodo Gurk, M., Tezkan, B. P Site Effect Assessment in The Mygdonian Basin (EUROSEISTEST area, Northern Greece) Using TEM and RMT

Soundings

V19 Worzewski Tamara Jegen, M., Kapionos, G., Brasse, H. O Using Amphibious Magnetotellurics to image Hydration and Dehydration of the Costa Rican Subduction Zone and

to demonstrate the bathymetric effect on marine data

V26 Yogeshwar Pritam Tezkan, B., Israil, M. O Grundwasserkontamination bei Roorkee/Indien:

2D Joint Inversion von Radiomagnetotellurik und Gleichstromgeoelektrik Daten

D05 Yu Gang T. Hanstein, Z. X He, I. M. Þorbergsdóttir, K.-

M. Strack, and H. Tulinius

D Geothermal exploration using MT and gravity techniques at Szentlőrinc area in Hungary

P Poster

O Oral

D Diskussionsbeitrag

PW Kurzbeitrag zu Peter Weidelt

Dienstag 29.9. – 8:50 – 12:10 V01 3-D conductivity image of the deep magma sources of the Taupo Volcanic Zone, New Zealand HEISE Wiebke1, 2, CALDWELL T. Grant1, BIBBY Hugh M.1, BENNIE Stewart L.1 1GNS Science, Lower Hutt, New Zealand 2 Universidade de Lisboa, CGUL-IDL, Lisbon, Portugal The Taupo Volcanic Zone (TVZ), in the North Island, New Zealand is a continental back arc rift associated with the subduction of the Pacific Plate under the Australian Plate and is characterised by the eruption of large volumes of rhyolitic magma during the last 1.6 Ma and an exceptionally high present-day heat flow. Magnetotelluric data had been collected in the TVZ since 1997 to study the deep structure and volcanism of the TVZ but also for exploration of the geothermal systems. We present results from over 200 magnetotelluric soundings covering the central (rhyolitic) part of the TVZ. The data were analysed using 3-D inverse resistivity modelling and phase tensor visualisation techniques. The inverse modelling results show areas of high conductivity in the lower crust and upper-mantle along the central rift-axis that correlate with a zone of high phase observed at long periods. These conductors are interpreted as the magma reservoirs which are the source for large scale rhyolitic eruptions that occur in the TVZ. The varying conductivity along the rift axis represents different percentages of eruptible magma in the mush zone. A deep reaching conductor suggests that we observe a plume of hot magma recharging the magma reservoir. V02 Magnetotelluric study of Lascar volcano, Central Andes. D. Diaz1, H. Brasse1, M. Banaszak2 1Freie Universität Berlin, Fachrichtung Geophysik, Malteserstr. 74-100, 12249 Berlin, Germany (d.diaz@geophysik.fu-berlin.de) 2Universität Göttingen, Geowissenschaftliches Zentrum Göttingen, Abt. Geochemie, Goldschmidtstr. 1, 37077 Göttingen In the study of volcanoes and hydrothermal systems, magnetotellurics has been widely used considering the different electrical properties expected in these structures, due to hydrothermal fluids, gas or melt in contrast with the surrounding rocks (see, e.g., Heise et al., 2008; Müller et al., 2004). This investigation considers the zone around Lascar volcano (5592 m, 23°22’S, 67°44’W), located on the eastern side of the Salar de Atacama basin in northern Chile, as part of the volcanic arc which defines the western border of the Altiplano-Puna plateau. It has been one of the most active volcanoes of the central Andes in the last years, which recent activity has been characterized by repetitive dome growth and subsidence, accompanied by degassing and explosive eruptions of various magnitudes (Pavez et al., 2006). During October and November 2007, 13 AMT (250 Hz-1000s) sites were built around the Lascar volcano, while 11 LMT (10s-10000s) sites were built as an E-W profile, crossing the Salar de Atacama basin and the volcanic arc, reaching the Puna. To obtain the apparent resistivity curves from the time series, the real and imaginary parts of the impedance tensor were calculated with the robust processing from Egbert (Egbert, 2002). Analysis of the

induction vectors, phase tensor ellipses and strike direction (Smith, 1995) were developed, obtaining a consistent 2D regional behavior for the periods between 100s and 1000s. 2D inversion developed for the LMT profile shows the main geological features of this zone, such as the Salar de Atacama basin, the Precordillera and the Atacama block, as well as a large conductive body under the Altiplano-Puna plateau, a result which is in good agreement with previous studies in the Central Andes (Brasse et al., 2008). For the AMT data, a 2D inversion was also obtained, showing a shallow conductive zone (2-3 km) under the volcanic edifice, and extending deeper to the SE. Based on these results and considering petrologic and geochemical studies in the area, 3D forward modeling have been under development using the AMT stations closest to the volcano, obtaining the best results (until now) for a synthetic magma chamber elongated to the south. References -Brasse H, Eydam D (2008) Electrical conductivity beneath the Bolivian Orocline and its relation to subduction processes at the South American continental margin. Journal of Geophysical Research, 113, B07109, doi:10.1029/2007JB005142. -Egbert G D (2002) Processing and Interpretation of Electromagnetic Induction Array Data. Surveys in

Geophysics, 23: 207-249. -Heise W, Caldwell T G, Bibby H M & Bannister S C (2008) Three-dimensional modeling of magnetotelluric data from the Rotokawa geothermal field, Taupo Volcanic Zone, New Zeland. Geophysical Journal International, doi:10.1111/j.1365-246X.2008.03737.x -Müller A, Haak V (2004) 3-D modeling of the deep electrical conductivity of Merapi volcano (Central Java): integrating magnetotellurics, induction vectors and the effect of steep topography. Journal of

Volcanology and Geothermal Research, 138: 205-222. -Pavez A, Remy D, Bonvalot S, Diament M, Gabalda G, Froger J-L, Julien P, Legrand D & Moisset D (2006) Insight into ground deformations at Lascar volcano (Chile) from SAR interferometry, photogrammetry and GPS data: Implications on volcano dynamics and future space monitoring. Remote

Sensing of Environment, Volume 100, Issue 3: 307-320. -Smith J.T (1995), Understanding telluric distortion matrices, Geophysical Journal International, 122, 219-226. V03 Dominant phase split in MT data from the Western branch of the East African Rift in Uganda explained by a preliminary three dimensional model with an electrically anisotropic lithosphere Michael Häuserer, Andreas Junge Long Period Magnetotelluric (LMT) measurements were performed at up to 14 sites simultaneously within an area of 150 km x 80 km east of the Rwenzori Mountains during 2 field campaigns in 2007 and 2008. The Rwenzories are located in the western branch of the East African Rift in the west of Uganda near the Congo border. Altogether at eight sites time variations of both Magnetic and Telluric fields were recorded, whereas at 15 sites only the Electric field components were observed. MT transfer functions and phase tensor ellipses were estimated at all sites in the period range 10-10000s due to a rather homogeneous source field. Large distortions of the transfer functions indicate a complicated three dimensional conductivity structure within the crust predominantly at the transition zone between the Rwenzori Mountains and the Rift shoulder to the North East. The overall pattern of the phase tensor ellipses shows a consistent split of the minimum and maximum phase for all sites at periods >100s. The high maximum phases >60° are associated with currents perpendicular to the Rift Valley and the minimum phases (45°) with currents parallel to the Rift. The high phase component over the period range 100-10000 sec indicates a downwards decreasing conductivity within the lithosphere. The constant phase

split over a large lateral distance and the small vertical magnetic filed components at long periods can be explained by a model with anisotropic conductivity in the lithosphere. Generally all impedance phases increase above 45° for periods longer than 2000 s denoting an increase of the conductivity beneath the lithosphere. V04 The electrical conductivity structure of the Dead Sea Basin derived from 2D and 3D inversion of magnetotelluric data Meqbel N., Ritter O., Weckmann U., Becken M. and Muñoz G. V05 Motionally Induced Electromagnetic Field within the Ocean

K. M. Bhatt, A. Hördt, P.Weidelt (Inst. f. Geophysik u. Extraterrestrische Physik, TU Braunschweig), T. Hanstein (KMS Technologies - KJT Enterprises Inc.) The contribution of motionally induced electromagnetic (EM) fields at the seafloor is generally considered small, but since the characteristic reservoir signal in marine controlled source electromagnetic (mCSEM) data is also small, the inclusion of the motional induction contribution in modelling estimate will enhance the probability of reservoir detection. Here, we have studied the electromagnetic induction caused by ocean water flow with in earth’s magnetic field.

When a charge particle moves with certain velocity in earth’s magnetic field, it experiences a Lorentz force. The action of Lorentz force generates a secondary electric field through galvanic and inductive processes. For the mathematical formulation, thus, we considered Lorentz electric field as a source in the corresponding set of Maxwell’s equations. First, we solve these Maxwell's equations for a 1D model and velocity structure. Further, we extend our formulation for 1D model and 2D velocity structure. Here, Maxwell’s equations are solved by disintegrating them into TM and TE mode. For a vertical earth magnetic field, the TM and TE mode is energised respectively by horizontal and vertical component of velocity.

The simulations indicate that for practical cases at greater transmitter-receiver (T-R) separations, the motionally induced electric and magnetic field contribution is relevant for reservoir detection. For example, a surface wave of height 1 m propagating with velocity 25 cm/s of 0.04 Hz within an ocean of conductivity 3.33 S/m, in an ambient earth’s vertical magnetic field of 50000 nT, contributes an electric field of amplitudes 2 nV/m at the seafloor 1000 m below sea-surface. This amplitude corresponds to the signal amplitude measured at 7000 m distance from a transmitter with a dipole moment of 104 Am. V06 ”Air waves” in marine controlled-source electromagnetic - The potential of Peter Weidelt’s work Rita Streich In applications of marine controlled-source electromagnetics (CSEM) for hydrocarbon exploration,

energy propagating through the air (the “air wave”) often obscures subsurface signals. This has triggered a variety of hands-on industry approaches for handling airwave effects in CSEM data. These include the selection of frequency and distance windows that contain little airwave signal, up-down separation of EM fields, and related approaches similar to seismic predictive deconvolution. In contrast, Peter Weidelt(1) provides a comprehensive mathematical analysis of the nature and properties of air-related CSEM signals, which may lead to a deeper understanding and development of new approaches for dealing with the airwave problem. In this presentation, I attempt to provide an overview and illustration of Weidelt’s treatment of airwaves in 1D media, relate this to some of my own CSEM modeling test cases, and discuss potential consequences and future applications of this work in hydrocarbon exploration. (1) Weidelt, P., 2007, Guided waves in marine CSEM, Geophysical Journal International 171, 153-176

V07 From LOTEM to Marine tCSEM™ for hydrocarbon exploration: concepts and realization T. Hanstein, J. Löhken, I. Löhken, L. Mollidor, W. Qian, S. Ellingsrud, G. Yu, K.M. Strack The depth of interest for hydrocarbon exploration is from one to several kilometres. Transient electromagnetic techniques with controlled source as LOTEM and tCSEM™ for land and marine surveys are designed to reach this depth of penetration. The long offset and the conductive environment is convenient for acquiring the transient response as time series, which are processed by robust stacking and optimized filter techniques. Although in time domain the decay of the electromagnetic fields after a switch off the transmitter current is diffusive, assumptions and ideas of the seismic world is influencing the explanations for the response. Especially the concept of waves is used to describe the signal response of the ocean, the target and the air-sea interface with reflection and the refraction at the boundaries. Some aspects of the wave propagation explain the transient behaviour well but there are other aspects which are not consistent with the wave concept. The hydrocarbon target is often described as a thin resistive layer with finite horizontal dimensions. A thin and horizontal elongated rectangular resistor embedded in depth of 2 km below the seafloor has been applied for numerical experiment. Two tow lines have been modelled across the long side and the short side of the rectangular prism. The 3-D numerical modelling has been done with Comsol Mulitphysics and SLDMEM3T. The comparison of the results shows that both numerical method – finite element and finite difference with the Lanczos decomposition – are in good agreement. V08 Smoothness-constrained model error and resolution estimates from the inversion of direct-current resistivity and radiomagnetotelluric data Thomas Kalscheuer, Institute of Geophysics, ETH Zurich, Sonneggstr. 5, 8092 Zurich, Switzerland; Maria de los Angeles Garcia Juanatey, Department of Earth Sciences, Uppsala University, Villavagen 16, 75236 Uppsala Naser Meqbel, GeoForschungsZentrum Potsdam, Geophysical Deep Sounding, Telegrafenberg, 14473 Potsdam, Germany; Laust B. Pedersen, Department of Earth Sciences, Uppsala University, Villavagen 16, 75236 Uppsala

V09 Die Übergangsimpedanz einer kapazitiv angekoppelten Elektrode Andreas Hördt, Peter Weidelt, Anita Przyklenk

Institut für Geophysik und extraterrestrische Physik, TU Braunschweig Bei geoelektrischen Messungen über sehr schlecht leitendem Untergrund kann es von Vorteil sein, den Strom kapazitiv anzukoppeln. Dabei wird ein hochfrequentes Wechselfeld an eine Elektrode angelegt, die keinen direkten Kontakt mit dem Untergrund hat. Eine genaue Berechnung der Übergangsimpedanz einer solchen Elektrode ist notwendig, um zu beurteilen, unter welchen Bedingungen eine kapazitive Ankopplung einer galvanischen überlegen ist. Für die praktische Umsetzung ist die Frage von Bedeutung, ob es günstig ist, eine kapazitive Elektrode zu isolieren und einen galvanischen Kontakt auszuschließen. Die Standardformeln für die Ankopplung kapazitiver Elektroden sind allerdings nur für hohe Leitfähigkeiten des Untergrundes gültig. Es wird eine Möglichkeit vorgestellt, die Impedanz einer Kreisscheibe zu berechnen, die an einen Halbraum mit endlicher Leitfähigkeit angekoppelt ist. Basierend auf den Maxwellgleichungen wird eine Integralgleichung für die Ladungsdichte q auf der Kreisscheibe aufgestellt. Mit der Randbedingung, dass das Potential auf der Scheibe konstant ist, kann die Ladungsdichte und damit die Gesamtladung bestimmt werden. Es zeigt sich, dass der Übergang von aufliegender zu angehobener Platte stetig als Funktion des Abstandes verläuft. Zudem nimmt die Impedanz als Funktion des Abstandes zu, d.h. die Ankopplung einer kapazitiv angekoppelten Elektrode kann niemals geringer sein, als die einer aufliegenden mit gleicher Fläche. Je nach Modellparametern kann die Impedanz jedoch innerhalb weniger Nanometer über Größenordnungen variieren, so dass es dennoch günstig sein kann, die Elektrode zu isolieren, um starke Schwankungen der Impedanz zu vermeiden. V10 Nachruf Peter Weidelt Andreas Hördt V11 Some remarks on Peter Weidelt’s influence on Scandinavian EM research Laust Pedersen I met Peter Weidelt and Ulrich Schmucker first time at the Ottawa Induction Workshop in 1974 a few years after I joined Aarhus University in Denmark. Shortly after both of them, much to my surprise, accepted an invitation to come to Aarhus to teach EM induction theory to a small, but dedicated group of students, including myself. The well-known Aarhus Lecture notes from the spring of 1975 is the legacy from those intensive lectures which went on for 2 times six weeks. During my presentation I will mention some important outcomes in terms of Scandinavian people and papers resulting directly or indirectly from especially Peter’s lectures.

Mittwoch 30.9. – 8:30 – 11:50 V12 Full Field EM Monitoring K.-M. Strack, T. Hanstein and G. Yu KMS Technologies – KJT Enterprises Inc., Houston, Texas, USA

Increasing production efficiency and monitoring water/steam/CO2 floods are key issues to be addressed with borehole and surface technologies and measurements. At the same time linking the information to 3D surface seismic data and borehole seismic data is required to extrapolate in the inter-well space, find the sweat spots between wells, and in the 3D reservoir space. Controlled source electromagnetic has the strongest coupling to the fluid content of the reservoir while seismic can delineate impedance contrasts or lithological boundaries. Present logging technologies only reach about 3 meters away from the well bore. Deep reading techniques are still in commercial field trial stage. Surface electromagnetic techniques are presently proposed and only used for monitoring application in engineering geophysics. The reason lies in the higher order sensitivity and resolution decay with distance from the target. A logical conclusion is to combine methods not only to sense different physical reservoir properties but also to overcome the weakness of each method and to approach the problem in a more synergetic fashion. We evaluated several reservoir dynamics monitoring methods and technologies leading us to a practical concept of Full Field Fluid Monitoring (F3M). Our implementation includes marine and land sources and receivers, surface-to-borehole arrays and single well system that can look tens or even 100 m around the wellbore and ahead of the drill bit. Except for the single well component, all systems are well past the research phase and we have carried out various parts of field trials. The enabling technology is a multi-component cable we are building for marine application which can measure magnetotellurics as well as controlled source EM signals. It allows much denser data collection, operational cost efficient, and semi-permanent or permanent operation ,and it can also be combined with nodes to cover a larger footprint with wider spacing. Similar technology with a variety of fit-for-purpose telemetry can be used onshore. For borehole use we are combining our EM sensor packages with borehole seismic acquisition system or build special purpose LWD sub-assemblies. In all case the data can be acquired and streamed over the internet to allow efficient operation and real time control of the water/steam/CO2 floods. One of the major learnings during the various projects was that surface electromagnetic methods alone are ambiguous if they are not used in combination with surface-to-borehole measurements. The reason lies in the up-scaling issues associated with the inherent averaging nature that EM methods do.

V13 Marine CSEM activities at BGR: - Gas hydrate studies in New Zealand - Instrument developments: A new bottom-towed multi-receiver system

Katrin Schwalenberg, Martin Engels, Joachim Deppe, Marion Jegen, and the New Vents Working Group V14 Erkundung der Süßwassergrenze des unterseeischen Aquifers vor der Küste Israels mit der LOTEM-Methode. K. Lippert, B. Tezkan, R. Bergers, M. Gurk, M. v. Papen, P. Yogeshwar Institut für Geophysik und Meteorologie, Universität zu Köln Im Rahmen dieses BMBF-geförderten Projektes kommt die Long-Offset Transient Elektromagnetik (LOTEM) Methode zum ersten Mal in mariner Umgebung zur Erkundung von Grundwasseraquiferen zum Einsatz. Hauptziel des Projektes ist die Detektion der Süßwassergrenze unter dem Mittelmeer an der Küste Israels. Zu diesem Zweck wurden Hardware-Modifikationen durchgeführt und bereits in einer ersten Testmessung in Israel erprobt. Des weiteren werden die Interpretationen der ersten Testmessung sowie die Modellierungsergebnisse des Küstenabschnitts vorgestellt, welche zur Planung der Hauptmessung wichtig sind. V15 Harmonic oscillations in EM-signals measured on the "North Alex" mud-volcano Sebastian Hölz Ocean bottom MT-measurement (OBMT) taken at six locations on the "North Alex" mud-volcano in the Mediteranean Sea repeatedly show oscillations in the EM-fields. These oscillations typically last several hours and can be characterized in spectrograms by peaks at periods of 3s, 6s and 12s. We will present evidence that these signals are neither caused by mechanical instability of our OBMT-stations, nor due to regular MT-signals. Instead we propose that these signals are triggered by activity of the mud volcano itself. V16 Einfluss von Bathymetrie auf marine CSEM Messungen im Zeitbereich Bücker, M., Kenkel, J., Hördt, A. (Institut für Geophysik und extraterrestrische Physik, TU Braunschweig) Hanstein, T. (KMS Technologies – KJT Enterprises Inc.)

V17 Magnetotelluric study in northeastern Botswana Marion P. Miensopust, Alan G. Jones, Mark R. Muller, Mark P. Hamilton, Xavier Garcia, Rob L. Evans, Patrick Cole, Tiyapo Ngwisanyi, David Hutchins, C.J.S. Fourie, Heilke Jelsma, Theo Aravanis, Wayne Pettit, Sue Webb, Jan Wasborg, and The SAMTEX Team The proposed boundaries of geological terranes in northeastern Botswana are mainly based on regional magnetic and gravity data, because there are not many outcrops available due to the thick Phanerozoic cover rocks. The extent of the Zimbabwe craton into Botswana as well as the location of the boundaries to its neighbouring mobile belts (Limpopo Belt, Magondi Mobile Belt and Ghanzi-Chobe Belt) are not very well known. Magnetotelluric (MT) profiles of the Southern African MagnetoTelluric Experiments (SAMTEX) are present in this area and provide information about lithospheric strike directions and the resistivity distributions as well as possible locations of terrane boundaries, which verify some of the proposed terrane boundaries and suggest modification for others. V18 Imaging the Kaapvaal Craton boundary, South Africa, using Magnetotellurics U. Weckmann, M. Becken, O. Ritter & M. de Wit Within the framework of the German-South African geo-scientific research initiative Inkaba yeAfrica several magnetotelluric (MT) field experiments were conducted along the Agulhas- Karoo transect in South Africa. This 600 km long transect is designed to cross several continental collision zones, in particular the boundary of the Kaapvaal Craton with the Namaqua Natal Mobile Belt. MT data from 120 sites across the craton boundary were inverted to obtain a two dimensional electrical conductivity distribution on a lithospheric scale. The most intriguing feature of the inversion model is the distinct difference between relatively high conductivities of the metamorphic rocks of the mobile belt und the extremely resistive rocks of the Kaapvaal Craton. The area of the craton transition is characterized by resistive blocks extending into the Earth’s mantle intersected by zones of higher conductivity which seem to correlate with thrust and fault systems of the Gordonia Subprovince and the Marydale Terrane. Both tectonic structures are believed to have experienced a similar stress field to the adjacent Kaapvaal Craton. Petrological and seismological data in the area also show strong similarities with measurements on the craton rather than with results from the mobile belt. Based on the electrical conductivity of the Gordonia and Marydale rocks we believe that their composition is much more comparable to that of the Archean Kaapvaal rocks than to rocks of the Namaqua Natal Mobile Belt. With our MT results the discussion of the location of the craton boundary at depth is resumed. V19 Using Amphibious Magnetotellurics to image Hydration and Dehydration of the Costa Rican Subduction Zone and to demonstrate the bathymetric effect on marine data T. Worzewski1, M. Jegen1, G.Kapinos2, H. Brasse2 1 SFB574, IFM-Geomar, Kiel 2 FB Geowissenschaften, Freie Universiät Berlin

We present an image of the electrical structure of the Costa Rica subduction zone based on an amphibious magnetotelluric (MT) profile. In the framework of SFB 574 (‘Volatiles and Fluids in Subduction Zones’), we deployed 11 stations on a 200km long marine profile, where the Cocos Plate subducts beneath the Caribbean plate. We will present the marine data and its processing, with special focus on the recorded transfer functions having unusual shape in relation to a bathymetric effect that shall be discussed. We also will show final modeling results and their interpretation: The data set revealed a very low electrically conducting oceanic lithosphere entering the subduction zone. Upon entering the subduction, near the trench, the oceanic lithosphere undergoes a moderate enhancement in conductivity down to deep crustal and upper mantle regions, which may be attributed to hydration caused by water penetrating along bending related faults and cracks. A first accumulation of free water caused by subsequent dewatering reactions is observed in the forearc sediments above the décollement updip of the seismogenic zone. Further inland, a well conducting zone in the overriding plate, at about 20-30 km depth, may be interpreted as a fluid trap, while a conductive zone underneath, at about 120km depth, might hint at dehydration of crust and deserpentinization of mantle. This feature in 20-30 km depth is observed in land MT measurements on subduction zones all over the world in comparable distances to the volcanic arc, and thus seems to be a robust feature, but was yet not recognized as such. V20 3-D model study to determine the mantle conductivity of the SW Iberian Peninsular using phase tensor methods ADÃO Filipe, HEISE Wiebke Universidade de Lisboa, CGUL-IDL, Lisbon, Portugal The phase relationship between the horizontal electric and magnetic fields represented by the phase tensor is undistorted by the heterogeneities present in a geological medium. Its graphical representation allows the detection of structure in depth and lateral discontinuities of resistivity, like a regional strike or the presence of an ocean (Caldwell et al., 2004). To test these capabilities, a synthetic 3-D model, based on the model of Santos et al. (2001), was made to obtain synthetic phase tensors, geographically placed in the same location as the stations from the profiles I, S, P,O e L, defined by Muñoz et al. (2008), using the 3-D finite difference algorithm described by Mackie et al. (1994). The superior mantle (30-80 km) resistivity value was alternated between 500, 5000 and 50000 Ωm, in order to observe the resistivity effect on the rendered phase tensors. The calculated phase tensors were also compared with the real phase tensors obtained in the field in order to establish common points between model and reality.

Donnerstag 1.10. – 8:30 – 14:45 V21 EM fields generated by finite-length wire sources in 1D media: comparison with point dipole solutions R. Streich, M. Becken In present-day land and marine controlled-source electromagnetic (CSEM) surveys, EM fields are commonly generated using wires that can be hundreds of meters long. Nevertheless, when simulating CSEM data, e.g., for the purpose of feasibility studies or within inversion algorithms, these sources are often approximated as point dipoles. Such an approximation is justified if the source-receiver distance is sufficiently large and the frequency sufficiently low. However, real surveys often include frequencies and distances at which the dipole approximation is inaccurate. We consider horizontally layered media, for which EM fields can be computed using well-known quasi-analytical solutions that involve numerical evaluation of Bessel function integrals. In CSEM simulations, such 1D solutions are also an important component for computing background fields in higher-dimensional modeling and inversion. Using these 1D solutions, EM fields due to finite-length wire sources can be synthesized by representing the wire as a line of infinitesimal dipoles and integrating over the dipole fields. However, this procedure is computationally expensive, since it requires a large number of numerical integrations. We employ a more efficient formulation that contains explicit contributions from the end points of the wire and involves fewer integrals over the wire itself than a corresponding integration over point dipole fields. With our formulation, we can efficiently simulate complicated wire geometries by segmenting the wire and computing responses for each segment separately. This is particularly important for real field conditions on land, where kilometre-long current cables can usually not be laid out in an exactly straight line. Furthermore, our formulation permits to place both the wire and the receivers at any depth within the layered medium, an important aspect for marine applications as well as for borehole geometries. We will show examples of EM fields due to finite-length wires in various settings over the frequency and distance ranges of typical CSEM surveys, including surface-based and borehole geometries, and discuss differences to the fields due to infinitesimal dipoles. V22 A 3-D Model Study for Marine EM Using Vector Finite Elements Schwarzbach, C., Börner, R.-U., and Spitzer, K. (TU Bergakademie Freiberg) V23 Three-dimensional FE simulation of magnetotelluric fields using digital terrain models exemplified for Stromboli volcano Kütter, S., Franke-Börner, A., Börner, R.-U., Spitzer, K. (TU Bergakademie Freiberg)

V24 Towards 3D joint inversion of full tensor gravity, magnetotelluric and seismic refraction data Max Moorkamp (1), Marion Jegen (1), Richard W Hobbs (2), Alan Roberts (2) and Bjorn Heincke (1) 1. IFM-GEOMAR, Wischhofstrasse 1-3, 24149 Kiel, Germany. 2. Department of Earth Sciences, University of Durham, Durham, United Kingdom. Joint inversion of different datasets is emerging as an important tool to enhance resolution and decrease inversion artifacts in structurally complex areas. Performing the inversion in 3D allows us to investigate such complex structures but requires computationally efficient forward modeling and inversion methods. Furthermore we should be able to flexibly change inversion parameters, coupling approaches and forward modeling schemes in order to find a suitable approach for the given target. We present a 3D joint inversion framework for scalar and full tensor gravity, magnetotelluric and seismic data that allows us to investigate different approaches. It consists of two memory efficient gradient based optimization techniques, L-BFGS and NLCG, and optimized parallel forward solvers for the different datasets. In addition it provides the necessary flexibility in terms of model parameterization and coupling method by completely separating the inversion parameters and geometry from the parameterization of the individual method. This separation allows us to easily switch between completely different types of parameterizations and use structural coupling as well as coupling based on parameter relationships for the joint inversion. First tests on synthetic data with a fixed parameter relationship coupling show promising results and demonstrate that 3D joint inversion is becoming feasible for realistic size models. V25 Joint Inversion of Magnetotelluric and Surface Wave Data in an Anisotropic Earth E. Roux (1), M. Moorkamp (2), A.G. Jones (1)

(1) Dublin Institute for Advanced Studies, School of Cosmic Physics, 5 Merrion Square, Dublin 2, Ireland

(2) IFM Geomar, Wischhofstrasse 1-3, 24148 Kiel, Germany This work involves inverting simultaneously surface waves dispersion curves and long-period magnetotelluric measurements (sensitive to shear-wave velocity and electrical measurements respectively) in a one-dimensional anisotropic media. Assuming that seismic and electrical anisotropy have a common origin, we can thus expect superior resolution of azimuthal anisotropy for lithospheric and sub-lithospheric depths combining these two techniques. We have examined the capabilities and limitations of this new approach with synthetic datasets and obtained encouraging results. Another convincing way to validate the algorithm is to apply it to real datasets. However, finding a suitable site to apply this new method remains challenging as we need good quality MT and seismic measurements for coincident sites. Central Germany is a good candidate for such an inversion because of existing knowledge and data. Here, we present some tests with synthetics datasets as well as a first application of such a joint inversion in anisotropic media to a real dataset from Central Germany.

V26 “Grundwasserkontamination bei Roorkee/Indien: 2D Joint Inversion von Radiomagnetotellurik und Gleichstromgeoelektrik Daten” P. Yogeshwar1, B. Tezkan2, M. Israil3 Universit¨at zu Köln, Institut f¨ur Geophysik und Meteorologie 1: yogeshwar@geo.uni-koeln.de, 2: tezkan@geo.uni-koeln.de, 3: mohdfes@iitr.ernet.in (Institute of Earth Sciences, IIT Roorkee/India) Die hier vorgestellte Arbeit wurde in Zusammenarbeit mit dem IIT-Roorkee (Indian Institute of Technology/ Roorkee) im Rahmen eines deutsch-indischen Partnerprojektes mit dem Titel: “Groundwater contamination due to waste disposal and aquifer characterization around Roorkee using integrated Geolelectric techniques” durchgeführt. Das Hauptanliegen des Projektes besteht in der Anwendung geophysikalischer Methoden zur Abschätzung der Gefährdung der Aquifersysteme der Region um Roorkee. In der landwirtschaftlich geprägten Region um Roorkee ist der Einsatz von Düngemittel sowie die Bewässerung der Felder mit Abwasser gängige Praxis, wobei das Abwasser durch offene, teilweise nicht betonierte Kanäle transportiert wird. Die umliegende Landbevölkerung bezieht ihr Frischwasser oftmals aus Brunnen, die aus oberflächennahen Aquiferen gespeist werden. Eine Gefährdung dieser oberflächennahen Aquifersysteme durch den praktizierten Umgang mit Abwasser und Düngemittel ist nicht auszuschließen. Im Rahmen dieser Arbeit wurde ein landwirtschaftlich genutztes und stark mit Abwasser bewässertes Gebiet nahe einer Müllkippe mit den Methoden der Gleichstromgeolelektrik und der Radiomagnetotellurik profilhaft vermessen. Hierbei wurde das vierkanalige RMTF Gerät der Universität zu Köln benutzt, welches im erweiterten Frequenzbereich von 10 kHz bis 1 MHz misst. Die einzelnen Profile wurden neben Benutzung von gängiger 1D und 2D Auswertesoftware mittels eines neu entwickelten 2D Joint Inversionsprogrammes invertiert und interpretiert. Das Ziel ist durch die Anwendung der 2D Joint Inversion verbesserte Untergrundmodelle zu erhalten und eine Aussage über die Kontaminationsverbreitung und gegebenfalls Ausbreitungsrichtung von Kontaminationsfahnen machen zu können. V27 Improvement of the geophysical imaging by MT and Gravity joint inversion: Application to Turkana region, Northern Kenya. Abdelfettah1,* Y., P. Tarits1, S. Hautot1, M. Maia1 and J-J. Tiercelin2 1 IUEM-UBO, UMR CNRS 6538 “Domaines Océaniques”, Plouzané, France 2 Géosciences Rennes, UMR6118, Université de Rennes, France * Now he is in Neuchatel University, Suisse Understanding geology from geophysical investigation is best when information is obtained from different kinds of data. A single method may not have sufficient resolution to provide the expected information. Joint inversion is a step forward to quantitatively combine data of different nature. Here, we present a solution for the joint inversion between MT and gravity data. The depth resolution but poor spatial coverage of MT data may be complementary of gravity data with excellent spatial coverage but little vertical resolution. Joint inversion may be considered in two different ways, petrophysical or structural. Joint inversion technique based on structural approach is developed and applied to crust and upper mantle imaging of the Turkana Rift (North of Kenya), in the East African Rift. The Turkana area is the transition zone between the Eastern and Main Ethiopian rifts. The geology is comprised of thick basalt

layers on top of sandstones and bedrock. Seismic studies suggested the presence of Paleogene sediments underneath the sandstones but this still remains uncertain because of the poor data quality due to the important basaltic cover. We jointly inverted magnetotelluric (MT) and gravity data collected along profiles on the western bank of Lake Turkana. To achieve this result, we developed a joint inversion algorithm based on a common structure approach for both MT and gravity. A preliminary MT model is obtained from which a prior density model is derived from the joint MT-gravity inversion. The aim of work is focused on two scales: the basins and the crust. We imaged two basins in the area where the data are acquired. The result confirms some previous information and brings new information for the basin's structure. For the crust, the models obtained showed conductive bodies with low densities in the lower crust. These anomalies can be related with a melt material which might come from the upper mantle. V28 Integrated nonseismic geophysical studies to assess the site effect of the EUROSEISTEST area in Northern Greece (IGSEA)

Marcus Gurk This project aims to assess site effects in the surrounding area of the EUROSEISTEST site in Northern Greece by means of low-cost integrated nonseismic geophysical methods that are capable of detecting vertical geotectonic boundaries and fault zones with high accuracy and are able to confine and improve one of the first 3D resistivity inversion models of the area. Engineering seismology is a multidisciplinary field of research, covering the entire spectrum of the seismic-hazard assessment problem: earthquake source (seismicity, detph range, etc.), propagation path (seismic-wave propagation and attenuation) and local site effects (faulting mechanism, fault geometry, geophysical parameters for the layers down to the top of basement, water migration, hydrothermal activity, etc.). To overcome problems in the MT database and to confine the 3D resistivity model, IGSEA will use a magnetic survey aimed to identify differences between the MT model and the magnetic maps that can be associated with vertical structures and to perform a joint 2D inversion of MT and magnetic data along hereafter selected profiles. In a second stage of IGSEA, Radio-Frequency Electromagnetic techniques (RF-EM & RF-EM_grad), novel Transient Electromagnetic methods (TEM, Hoerdt et al., 2000; Scholl et al., 2008) and Radio- Magnetotelluric (RMT; Bastani, 2001) will be applied to map and image the identified vertical structures followed by an integrative self-potential tomography to estimate the actual hydrothermal regime. V29 Airborne EM sea ice thickness sounding: Forward modelling and hardware developments S. Hendricks1, C. Haas1,2, L. Rabenstein1, J. Lobach3 1) Alfred-Wegener-Institute for Polar and Marine Research, Bremerhaven, Germany 2) University of Alberta, Dept. of Earth & and Atm. Sciences, Edmonton, Alberta, Canada 3) Ferra Dynamics Inc., Mississauga, Ontario, Canada In the recent years, airborne frequency-domain EM has became the de-facto standard for regional sea ice thickness surveys and a validation tool for satellite observations in the Polar Regions. The Alfred Wegener Institute operates single-frequency Birds (4 kHz) with Helicopters and with a DC3-Turbo aircraft in the Arctic since 2009.

In general the conductivity of sea ice is negligible compared to the high conductivity of sea water. Therefore, the vertical conductivity distribution of a level ice floe can be approximated by a homogenous halfspace, whereas the sea water represents the only conducting layer. This 1D approach allows efficient sea ice thickness retrieval. Frequent ice deformation zones however, feature significant sub-footprint scale variability of sea ice thickness and conductivity. A 3D forward model, based on the finite-elements toolbox Comsol Multiphysics, is used to assess the error of the 1D method over deformed ice. In the future, the forward model should be used to estimate the feasibility of enhanced data processing over deformed ice. Especially the internal conductivity of blocky ice structures is of interest, which can be related to the internal sea water content. The large interface surfaces between ice and water of these structures are vulnerable to melt processes in the warming Arctic Ocean. V30 DEVELOPMENT AND TEST OF A FIXED WING AEM SEA ICE THICKNESS SOUNDER. Lasse Rabenstein, Alfred-Wegener-Institute, Bussestr. 24, 27570 Bremerhaven, Germany Stefan Hendricks, Alfred-Wegener-Institute, Bussestr. 24, 27570 Bremerhaven, Germany Christian Haas, University of Alberta, 1-26 Earth Sciences Building, Edmonton, AL, Canada, T6G 2E3 John Lobach, Ferra Dynamics Inc., Mississauga, ON, Canada, L5L 3B9 With five years of successful helicopter electromagnetic (HEM) sea ice thickness measurements the Alfred Wegener Institute (AWI) decided to construct an EM platform on a fixed wing aircraft in an attempt to overcome the helicopter flight range restrictions. The system operates in the frequency domain with 1990 Hz and a vertical coplanar coil configuration. The primary field voltage is electrically attenuated on the receiver coil which allows for increased amplification and resolution of the much smaller amplitude secondary field voltage. Before data are converted to ice thickness a correction for electronic drift and orientation effects is applied. First test flights show that the ice thickness accuracy of the fixed-wing system lies only between 1 m and 2.5 m in comparison to 0.1 m for the HEM systems. The lower accuracy is probably caused by electrical noise of the airplane engines and coil motion. V31 ORIENTATION TRACKING METHOD FOR MOBILE GEOPHYSICAL MEASURING SYSTEMS Johannes B. Stoll, Celle Inertial orientation tracking is based upon the same methods and algorithms as those used for missiles, aircraft, ships, manned and unmanned vehicles. Inertial angle tracking involves placing multiple magnetic, angular rate and gravity sensor units strapped down on a moving body. Integration of angular rate sensor data provides the information necessary to calculate the attitude of the moving body with respect to a fixed coordinate system, e.g. Earth reference. In combination with geophysical sensors (e.g. fluxgate, coil systems) inertial orientation tracking is an essential tool for geophysical sensor re-orientation with respect to a north-east-down (NED) coordinate system. The algorithm to derive the orientation of the three-dimensional motion of a borehole tool sensed by a triple of fibre optic rate sensors is discussed and an instructive example is given.

V32 Durchführung und Auswertung von dreikomponentigen Bohrlochmagnetometermessungen Virgil, C., Hördt, A., Leven, M., Steveling, E.

Dienstag 29.9. – Poster (16:00 – 18:00) P01 Zweidimensionale SIP-Modellierung mit anisotroper Leitfähigkeit Kenkel, J., Hördt, A. P02 Untersuchungen zur Genauigkeit der Spektralen Induzierten Polarisation K. Bairlein, A. Hördt, J. Kenkel (TU Braunschweig, IGEP) P03 SHOTEM Messungen im Arava Valley, Dead-Sea Transform Verwerfung, Jordanien -Vorbereitung der Wiederholungsmessungen im Dezember 2009 - A. Rödder, B. Tezkan Im Zuge des DESERT Projektes wurden im April 2004 bereits SHOTEM Messungen im Arava Valley gemacht. Hierbei wurde festgestellt, dass sich die oberflächennahe Seismik gut zusammen mit den SHOTEM Ergebnissen interpretieren lässt. Die neuen Profile sollen die alten zu einem 3D Grid ergänzen, geplant ist mit einer 50mx50m Senderspule und einem Stationsabstand von 50m zu messen. Desweiteren soll eine Wiederholungsmessung eines Profils durchgeführt werden, um eventuelle saisonale Effekte in der Hydrologie zu sehen. P04 Transienten Elektromagnetik und Geoelektrik zur hydrogeologischen Erkundung in der Haseldorfer Marsch. Andrea Treichel, Annika Steuer, Norbert Blindow P05 Data Processing of TEM timelines from first Israel measurement campaign Michael von Papen The 2008 measurement in Ashquelon, Israel produced TEM data with a specially developed transmitter in water and receiver stations on land as well as under water measuring horizontal electric and perpendicular magnetic components. Offsets vary between 200m and 550m. In this poster data processing of these timelines – done with SegyPro is decribed and a first Occam inversion is shown. The data is being sorted by on and off switches (50% duty cycle), levelled, filtered, stacked and analysed by clustering and with

quantiles of normal distribution. This is the basis for upcoming measurements as introduced by K. Lippert. P06 Site Effect Assessment in The Mygdonian Basin (EUROSEISTEST area, Northern Greece) Using TEM and RMT Soundings) Widodo Widodo, Markus Gurk, Bulent Tezkan

During the project “Euroseistest Volvi-Thessaloniki”, a strong-motion test site (EUROSEISTEST) for Engineering Seismology was installed in the Mygdonian Basin between the two lakes Volvi and Lagada ca. 45 km northeast of Thessaloniki (Northern Greece). The basin itself is a neotectonic graben structure (5 km wide) with increased seismic activity along distinct normal fault patterns. Fluvioterrestrial and lacustrien sediments (approximately 350-400 m thick) are overlying the basement consisting of gneiss with schist. To improve the seismic wave propagation model it is vital to know about site effects, e.g. the geotectonic properties of the area such as the top-of-basement, vertical tectonic boundaries (faults and basement fracturation) and the geothermal regime. Preliminary results of the site effects assessment in the EUROSEISTEST accomplished by TEM and RMT soundings are presented in this poster. P07 Hidden Mine Shaft Detection with Remote Radio Transmitter Electromagnetic and Self- Potential Method Frank Bosch and Marcus Gurk Abandoned near subsurface mining constructions from the 19th and early 20th century in urbanized areas placed upon former ore mines near the city of Aachen (Germany), and in many other regions of the world, provide hazardous risks concerning possible collapses. In many cases, the exact locations of such constructions are not known anymore. For instance, to map covered shafts of one meter diameter on large survey areas, high resolution methods with rapid measurement progress are necessary. Enhanced developments of the traditional Very Low Frequency (VLF) technique such as VLF-gradient and Radiomagnetotellurics (RMT) fulfill these requirements and can be used as inexpensive survey tools to characterize the investigation site and to suggest drilling positions and/or other geotechnical intrusive investigations. Continuous ground-contactless VLF-gradient survey quickly provides maps indicating the lateral electrical resistivity heterogeneity distribution. Inversions of RMT data provide 2D-resistivity-depth sections and also the interpretation of Self-Potential (SP) data gives information about the nature of the VLF-gradient anomalies. The successful combination of the three methods for detecting mineshafts is presented for both an electromagnetic undisturbed and noisy location. P08 Subsurface conductivity obtained from DC railway signal propagation with a dipole model Anne Neska

P09 ,,Übergangsimpedanzen von Elektroden zur Bestimmung elektrischer Widerstände von Monden und Kometen.“ A.Hördt, A.Przyklenk (IGEP, TU Braunschweig)

P10 Störkörperdetektion mittels 3-Komponenten-Magnetometerdaten Sebastian Ehmann1, Andreas Hördt1, Christopher Virgil1, Martin Leven², Erich Steveling1 1: TU Braunschweig 2: Universität Göttingen P11 Räumlich hochauflösende Vermessung magnetischer Anomalien mit einem unbemannten Luftschiff. Paul Gerke Hofmeister, Jan Grosser, Andreas Hördt, Karl-Heinz Glassmeier Institut für Geophysik und extraterestrische Physik Technische Universität zu Braunschweig p.hofmeister@tu-bs.de Auf einem Poster soll das unbemannte Luftschiff "Laputa" vorgestellt werden. Es dient der räumlich hochauflösenden Vermessung magnetischer Anomalien. Aus den Messungen sollen die Lag, Geometrie und physikalischen Parameter der Störkörper, die die magnetischen Anomalien verursachen, bestimmt werden. Die magnetische Kartierung von Flächen mit einigen Hektar Größe ist in einer Auflösung, wie sie bei Messungen mit handgeführten Magnetometern erziehlt wird, in kürzerer Zeit als bei bodengestützten Messungen möglich. Zudem können schwer begehbare Areale einfach vermessen werden. P12 Die deutsche Nordseeküste im Fokus von aero-elektromagnetischen Untersuchungen: I. Erkundung der Süßwasserlinsen von Borkum Annika Steuer1, Bernhard Siemon2 und Michael Grinat1

1Leibniz-Institut für Angewandte Geophysik (LIAG), Hannover 2Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover Die Insel Borkum ist die größte der Ostfriesischen Inseln. Sie besteht ausschließlich aus quartären Sedimenten, wie Sanden, Tonen und Schluffen. Bis Mitte des 19. Jahrhunderts war Borkum zweigeteilt in Ostland und Westland, getrennt durch einen Priel. Jeder Teil hatte seine eigene Süßwasserlinse. In der heute zusammengewachsenen Insel äußert sich die ehemalige Zweiteilung noch durch zwei separate Süßwasserlinsen. Durch den Orkan Kyrill Anfang 2007 gelangten Salzwassereinbrüche bis an den Rand des inneren Dünengürtels. Solche Ereignisse, aber auch der Tourismus in den Sommermonaten und der damit einhergehende verstärkte Wasserverbrauch gefährden die Süßwasserlinsen. Noch kann die gesamte Trinkwasserversorgung mit inseleigenem Grundwasser erfolgen. Von besonderem Interesse sind mögliche Veränderungen der Süßwasserlinsen. Daher erfolgten im Jahr

2008 an insgesamt 36 Schlumberger-Sondierungspunkten der Jahre 1991-1995 Wiederholungsmessungen. Es wurden keine signifikanten Veränderungen der Mächtigkeit der Süßwasserlinsen nachgewiesen. Mithilfe von hubschrauber-elektromagnetischen (HEM) Messungen konnte die Ausdehnung der Süßwasserlinsen flächendeckend kartiert und damit das potentielle Trinkwasservolumen der Insel abgeschätzt werden. Unter Berücksichtigung zusätzlicher Erkundungstechniken, wie der Gleichstromgeoelektrik, dem Direct-Push Verfahren und Bohrungen, konnten die Ergebnisse der HEM präzisiert werden. P13 Die deutsche Nordseeküste im Fokus von aeroelektromagnetischen Untersuchungen: II. Elbemündung und Langeoog mit Wattenmeer Gerlinde Schaumann1, Annika Steuer1, Bernhard Siemon2 und Helga Wiederhold1

1Leibniz-Institut für Angewandte Geophysik (LIAG), Hannover, Germany 2Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Hannover, Germany Hubschrauber-Elektromagnetische Untersuchungen bieten ein großes Potential für die flächendeckende Kartierung der Sedimente der ersten hundert Meter des Untergrundes. Sie sind für hydrogeologische Fragestellungen von großer Bedeutung, da mithilfe des spezifischen Widerstands die Verteilung sandiger und tonhaltiger Sedimente im Untergrund sowie Versalzungszonen ermittelt werden können. Im Jahr 2008 wurden im Rahmen des DAERO-Projektes Vermessungen zu Salz-/Süß-wasserfragestellungen im küstennahen Bereich, auf den ostfriesischen Inseln und im Wattenmeer sowie zur Grundwasserversalzung im Bereich der Elbemündung durchgeführt. Erste Ergebnisse werden in Form von Karten des scheinbaren spezifischen Widerstands und der Schwerpunktstiefe für die verschiedenen Messfrequenzen vorgestellt. P14 The Empirical Mode Decomposition and Spectra based on Direct Quadrature in MT data processing Jin CHEN, Marion JEGEN-KULCSAR SFB 574, IFM-GEOMAR, Wischhofstr.1-3, 24148, Kiel, Germany Here we present a data processing approach based on the EMD method which can deal with non-stationary MT time series. First, we use the EMD method to decompose the time series into several Intrinsic Mode Functions (IMFs), then construct the direct quadrature to each IMF to calculate the instantaneous frequency and instantaneous amplitude, finally, we calculate the marginal spectra to determine the impedance tensor. We tested the method with synthetic time series and real field time series. The comparison of the results with the traditional method is given at the end.

P15 Substitute models for static shift (in 2D) Kristina Tietze, Oliver Ritter, Ute Weckmann MT practitioners often down-weight apparent resistivity TE mode data prior to 2D inversion to avoid problems with static shift, obviously assuming that static shift of the TM mode is handled automatically by the inversion. Static shift is caused by conservation of charges at local conductivity discontinuities which are small with respect to the inductive scale length. Here we present a class of shallow conductivity anomalies which can produce significant up- or downwards shifted TM mode apparent resistivity curves (static shift in the TE mode cannot be simulated with 2D modeling). We examine how this static shift is reproduced by 2D inversion and show that the results are strongly influenced by grid design and regularization. We conclude that modern 2D inversion packages are not optimized to handle static shift. Our results also indicate that it is no good reason to assume that static shift is 0 on average. P16 A method to determine the magnetotelluric static shift from DC resistivity measurements in practice Tripaldi, S., Siniscalchi, A., and Spitzer, K. P17 Magnetotelluric measurements across the southern Barberton greenstone belt: Data analysis A. Nube1,2 , U. Weckmann1,2, O. Ritter1, X. Chen1,2 , J. Deacon3, S. MacLennan4, L. Moodley4, M. DeWit4, G. Willkommen2 , R. Barth2 , R. Streich1,2, K. Tietze1

The Kaapvaal Craton of South Africa is one of the oldest well-preserved continental fragments on our planet and thus is a key area for studies of geodynamic processes of the early Earth. One major controversy concerns the importance of plate tectonic processes in Archean times and the time when this may have been first initiated. Several potential ancient suture zones have been identified at the surface within the Barberton greenstone Belt, and these provide an ideal natural laboratory to test for possible subsurface remnants of mid-Archean plate tectonic processes on lithospheric scale. Within the framework of the German-South African geo-scientific research initiative Inkaba yeAfrica a high resolution magnetotelluric (MT) field experiment, ELIBABA, was carried out in April/May 2009 in the Barberton/Badplaas area, eastern Mpumalanga, RSA. A 120 km long profile and two complementary shorter 60 km long profiles with nearly 100 MT sites provide a good areal coverage of the Barberton suture and its complex geology. Strong cultural electromagnetic noise, possibly originating from nearby mines and the DC railway system, is present in the entire area of investigation. As this man-made noise is much larger than the natural electromagnetic signal, which we use to calculate the magnetotelluric transfer functions, advanced data processing schemes have to be used to obtain the cleanest possible sounding curves. This is of major importance for all later analysis steps as we have to make sure that our impedance tensor represents the conductivity structure of the subsuface and does not mirror the electromagnetic noise. We present first results of a standard data analysis in comparison with the remote reference technique and give an outlook

on other approaches aiming to improve the data quality. P18 Aufbau einer Controlled Source Magnetotellurik am GFZ M. Becken, R. Streich, O. Ritter Im Rahmen des Verbundvorhabens GeoEn, welches als Brandenburger Pilotprojekt im BMBF-Pogramm „Spitzenforschung und Innovation in den Neuen Ländern“ gefördert wird, wird in der MT Gruppe am GFZ Controlled Source MT (CSMT) etabliert. Ziel in GeoEn ist der kombinierte Einsatz aktiver und passiver MT zur Abbildung der elektrischen Leitfähigkeitsverteilung im Untergrund zur Erkundung und Überwachung von CO2-Speichern, geothermischen Reservoiren und unkonventionellen Gaslagerstätten (shale gas). Im Vergleich zur passiven MT besitzen CSMT-Messungen im Nahfeld von galvanisch eingespeisten Strömen ein anderes Sensitivitätsmuster, und zeichnen sich v. a. durch erhöhte Sensitivitäten gegenüber schlechten Leitern aus. Darüberhinaus sind Messungen in urbanen Gebieten mit passiver MT allein oftmals aufgrund des hohen Rauschpegels schwierig. Insofern sind aktive und passive MT komplementäre Verfahren zur Erkundung der oberen Kilometer der Erdkruste. Zur Erreichung unserer Ziele erfolgen parallel technische und methodische Entwicklungen zur CSMT. Dies beinhaltet einen Stromsender, der von der Firma Metronix neu entwickelt wird, Stromelektroden mit geringem Ankopplungswiderstand, Feldlogistik und Messtrategien, Datenprozessing sowie numerische Simulationsrechnungen und Inversionen. In unserem Beitrag stellen wir den Stand der Entwicklungen und die Projektziele vor. P19 Analysis of seafloor marine EM data with respect to motion-induced noise K. M. Bhatt, A. Hördt, (Inst. f. Geophysik u. Extraterrestrische Physik, TU Braunschweig) T. Hanstein (KMS Technologies - KJT Enterprises Inc.) P20

Donnerstag 1.10. – Poster (16:00 – 18:00) P21 TEM with anomalous diffusion in fractional conductive media T. Hanstein P22 1D-Simulation von Bohrlochtransientelektromagnetik zur CO2-Sequestrierung Kirchner, J., Börner, R.-U., und Spitzer, K. (TU Bergakademie Freiberg) P23 Die Felder des horizontalen elektrischen Dipols im geschichteten Halbraum Weißflog, J., Börner, R.-U., und Spitzer, K. (TU Bergakademie Freiberg) P24 Hybrid electromagnetic modelling of large surface loops on rugged terrain Jochen Lehmann-Horn P25 Advances in the Numerical Solution of the 3-D TEM Forward Problem Afanasjew, M., Börner, R.-U., Eiermann, M., Ernst, O. G., Spitzer, K. TU Bergakademie Freiberg, Germany Electromagnetic methods have recently gained much broader recognition in the exploration industry. However, challenging problems in the field of numerical simulation still remain. In this paper we address recent developments in numerical techniques which are most suitable for an efficient solution of the 3-D induction problem using transient dipole sources. We consider the numerical solution of electromagnetic induction due to a transient dipole source located on the surface of a half-space with an arbitrary 3-D conductivity structure. The spatial discretization requires an artificial boundary condition to be imposed at the air-earth interface to avoid discretizing the non-conducting air region. Such an exact boundary condition necessitates an efficient implementation of Fourier transforms on graded meshes. To avoid the undesired numerical overhead arising from using an FFT on non-uniform meshs, we precompute the action of the Fourier transform and interpolation operators on the discretized fields. Since these operators only depend on the mesh size, which remains constant throughout the time-stepping, the discrete action of the transform and interpolation can be

formally expressed by a matrix-vector product. We give examples which illustrate the gain in efficiency of the time-stepping of Maxwell’s equations. As a further aspect, we consider time-stepping via Krylov subspace methods. These are generalizations of the well-known SLDM method, for which we have developed memory efficient restarting techniques and a-posteriori error bounds. The time evolution of the electric and/or magnetic field can be expressed formally by an ordinary differential equation which incorporates a large sparse matrix representing the discrete curl-curl operator. Its solution is the matrix exponential applied to the vector of initial values. There exist a number of numerical techniques to approximate solutions to such problems involving matrix exponentials. Various implementations of this class of techniques will be discussed with respect to memory requirements, numerical efficiency, and accuracy. P26 Edge-based boundary element method for 3D RMT modelling incorporating surface topography - a theoretical study Zhengyong Ren, Thomas Kalscheuer, Hansrudolf Maurer, Institute of Geophysics, ETH Zurich, Sonneggstr. 5, 8092 Zurich, Switzerland P27 A scheme to invert magnetotelluric data in two and three dimensions on parallel computer architectures: Concepts and applications. Meqbel N., Ritter O., Egbert G. and Siripunvaraporn W. P28 Comparison of different coupling strategies in joint inversions B. Heincke, M. Jegen and M. Moorkamp Joint inversion is a very powerful strategy to integrate different geophysical data sets. In joint inversions model resolution of the used methods are generally improved and final results are less ambiguous than the results from the individual methods. One critical issue, however, is to find an adequate strategy to link data sets from the considered methods, if the methods are sensitive to different physical parameters (e.g. resistivity, seismic velocity and density). For subsurface conditions where all considered physical parameters strongly correlate with each other, one straight-forward implementation is to link the parameters in the inversion by fixed relationships. This strong but rigid coupling usually provides high model resolution, but introduces hardly predictable errors if the real parameter relationships differ strongly from the considered relationships in parts of the investigated region. In such cases strategies with weaker coupling are preferable. In this contribution we compare two different coupling strategies for joint inversion: a) Link by a fixed parameter relationship and b) the use of the relationships as mutual constrains in otherwise separate inversions. For comparing these two ways of coupling we use a joint inversion of MT and seismic traveltime tomography and gravity data. Both joint inversion methods are applied to a synthetic 2-D model that can be associated with a typical sub-basalt problem. We discuss resolution and quality for both

coupling strategies. Moreover, we investigate for both coupling strategies the effects onto the joint inversion results, if there are significant deviations from the assumed parameter relationships in parts of the model. For the joint inversion with coupling constraints it is also important to investigate how to find an adequate weighting of the coupling constrains relative to the data misfit - too weak coupling reduces the model resolutions, but too strong coupling introduces errors if significant deviations from the assumed relationships are present in the models. P29 Common Structure in Different Physical Properties: Electrical Conductivity and Wave S-Velocity Eric Mandolesi, A.G.Jones, E.Roux, S.Lebedev Recently different studies were undertaken on the correlation between diverse geophysical datasets. Joint inversion of different datasets in which a common structure is recognizable reduces non-uniqueness and may improve the quality of interpretation when different datasets are sensitive to different physical properties with an underlined common structure. In this poster the possibility to constrain inversion of magnetotelluric (MT) inversion results using seismic dataset is proposed and tested. Structural approach proposed by Haber and Oldenburg (1996) is tested; this approach suggest to minimize difference in structure, following the basic idea that change in physical properties occur at the same spatial locations. P30 Working towards modeling of phases over 90° with 2D anisotropic Inversion X. Chen1,2 , U. Weckmann1,2, K. Tietze1 1 Helmholtz Centre Potsdam - German Research Center for Geosciences, Potsdam, Germany 2 University of Potsdam, Institute of Geosciences, Germany Within the framework of the German - South African geo-scientific research initiative Inkaba yeAfrica three magnetotelluric (MT) field experiments were conducted along the Agulhas-Karoo Transect in South Africa. This transect consists of several continental collision zones and its respective units (Cape Fold Belt, Namaqua Natal Mobile Belt and Kaapvaal Craton). Along the profile we can identify areas (>10km) where phases over 90° occur. Due to the dense site spacing we are able to observe this behaviour consistently at several sites. Here we focus on the profile section between Prince Albert to Mosselbay. Isotropic 2D inversion is adequate to explain most parts along the profile but not the abnormal phase behavior which hints at electrical anisotropy. In order to develop a 2D inversion with spatially constraint anisotropy, resolution tests and synthetic modeling studies are necessary. In a first step towards the constraint anisotropic inversion zones with electrical anisotropy were included in a 2D isotropic inversion model in a trial and error approach to fit the phase curves > 90°.

P31 Thin sheet conductance models from geomagnetic induction data: Study of induction anomalies at the transition from the Bohemian Massif to the West Carpathians Cerv, V., Kovacikova, S., Menvielle, M. and Pek, J. Thin sheet approximation of Earth's conductive structures made it possible to quantitatively estimate effects of lateral conductivity variations in the Earth long before full 3-D electromagnetic modeling was practicable. The thin sheet approach is still useful when induction data with limited vertical resolution are to be interpreted on a surface. It especially refers to collections of long period induction arrows across large areas and geological units. For this purpose, inverse procedures, both linearized and stochatic, for a conductance distribution in a thin sheet have been suggested recently. We present a stochastic Monte Carlo inversion of geomagnetic induction data based on the bayesian formulation of the inverse problem. An example of the inversion of practical induction data from the transition zone between the Bohemian Massif and the West Carpathians suggests that an SW-NE anomalous induction zone observed above the eastern slopes of the Bohemian Massif admits explanation in terms of a phantom effect due to the superposition of fields of the strong SE-NW Carpathian conductivity anomaly to the east with NW-SE to W-E trending conductivity zones to the west that conform with the fault pattern of the eastern Bohemian Massif. P32 Magnetotelluric investigation of the Sorgenfrei-Tornquist Zone and the NE German Basin Schäfer, A., Brasse, H., Houpt, L., Weichelt, D. P33 Imaging fluids and melts in the crust and upper mantle of the Bolivian Orocline, Central Andes (18°S) – Interpretation of magnetotelluric data D. Eydam & H.Brasse Long-period magnetotelluric data were obtained between 2002 and 2004 in the Central Andes to study the electrical conductivity structure with focus on subduction related processes. The profile extends from the chilean Coastal Cordillera, crosses the Western Cordillera as the recent volcanic arc and the Altiplano high plateau in Central Bolivia and ends in the Eastern Cordillera. Horizontal components and the vertical magnetic field were measured at 30 stations with a spacing of about 10 km. Subduction related features near the slab like fluid curtains and fluid or melt pathways are best resolvable by the forearc stations. These stations had to be discarded from further interpretation by 2-D inversion, due to significant 3-D effects. However, the inversion revealed severeal features among which the most prominent is a huge conductor in the upper mantle below the high plateau which may be interpreted as an image of partial melt triggered by fluid influx from the subducting slab. The high conductivities range up to 0.2 S/m and indicate high melting rates of more than 6vol%. The melt should be stabilised by lithospheric mantle material beneath the high plateau which may trap hot mantle fluids and with this, probably prevent wide-scale crustal melting like this is the case in the southern Altiplano. Fluids and melts can be transported by mantle convection westward to the arc where

they may be stored in MASH-zones near the crust-mantle boundary; only few material should cross the thick crust. Some fluids and melts may rise up to the Eastern Cordillera. This “scenario” indicates a widely hydrated crust and upper mantle beneath the high plateau, which is consistent with other, significant geophysical anomalies measured here, like high heat flow densities, very negative Bouguer anomalies, very slow seismic velocities in a highly absorbing crust, elevated conductivities and a strong mantle signatur of geothermal fluids. But an interesting question is, how the water, released in the dehydrating slab, may supply a source region which is more than 50 km (lateral) away? Or in other words, why does the peridotite melt so far away from the water front? Some possible answers are presented. P34 Results of an amphibious magnetotelluric experiment at the South-Central Chilean continental margin Gerhard Kapinos and Heinrich Brasse FU Berlin, FR Geophysik, Malteserstr. 74-100, 12249 Berlin, Germany P35 Combining magnetotelluric and seismic models for exploration of the Groß Schönebeck geothermal site: a statistical approach Gerard Muñoz, Klaus Bauer, Inga Moeck, Oliver Ritter Geophysical exploration for geothermal resources is often challenging because information on the parameters of interest such as porosity, permeability, fluid content, etc., cannot be observed directly. Conventional (seismic) structure images are usually not sufficient to locate potential geothermal targets. Magnetotelluric (MT) and seismic methods provide information about the resistivity and velocity distributions of the subsurface in similar scales and resolution. The lack of a fundamental law linking the two parameters, however, limits a joint interpretation to a more qualitative analysis. Using a statistical approach in which resisitivity and velocity models are investigated in the joint parameter space, we can identify regions of high correlation between the two model parameters. Back-mapping of these regions onto the spatial domain allows us to identify common classes which can then be compared with lithological information. Application of this technique to a seismic – MT profile in the area of the Groß Schönebeck geothermal site, allows us to identify a number of classes in accordance with local geology. In particular, a high velocity – low resistivity class is interpreted as related to salt lows, where highly fractured anhydrite might produce enhanced permeability. P36 Magnetotelluric measurements to explore for deeper structures of the Tendaho geothermal field, Afar, NE Ethiopia Ulrich Kalberkamp BGR, Hannover

Electrical conductivity of the subsurface is usually one indicative parameter for geothermal resources. Due to the high temperatures of around 250 °C encountered at the Tendaho geothermal field (Afar depression) lacustrine sediments, highly mineralised waters, alteration products (Smectite) as well as molten or partly molten magma may contribute to low resistivities at various depths. The Tendaho geothermal field is located in the Afar depression within an area of active extensional tectonics where the Main Ethiopian Rift, the Red Sea and the Gulf of Aden form a triple junction. The Tendaho rift is part of the Tendaho-Goba'ad discontinuity where open fissures and active faults are observed, associated with hydrothermal manifestations. Previous DC geoelectrical soundings could not achieve penetration depths exeeding 500 m due to extremely well conducting surface layers. To reach a depth of exploration beyond 5 km the magnetotelluric method has been applied in a frequency range from 10 kHz to 0.01 Hz (100 s). 33 magnetotelluric soundings have been recorded and 2-dimensionally inverted. Within the modeled resistivity distribution the shallow (200 to 400 m depth) reservoir can be distinguished from the heat source, which is forming a dyke-like structure at depths below 7 km. This structure may be interpreted as part of the NW-SE trending Tendaho rift. In its northwesterly continuation the Dabbahu rift structure is hit, whose volcanic eruption in 2005 is thought to have formed new oceanic crust on continental litosphere (Wright et al. 2006). The MT survey in Ethiopia has been carried out as part of a technical cooperation project with the Ministry of Mines and Energy represented by the Geological Survey of Ethiopia (GSE) and the Federal Institute for Geosciences and Natural Resources (BGR) as part of the BGR GEOTHERM programme. GEOTHERM is a technical cooperation programme financed by the Federal Ministry for Economic Cooperation and Development (BMZ) to promote the use of geothermal energy in partner countries (www.bgr.de/geotherm/). Reference: Wright, T.J., Ebinger, C., Biggs, J., Ayele, A., Yirgu, G., Keir, D. & Stork, A., 2006, Magma-maintained rift segmentation at continental rupture in the 2005 Afar dyking episode, Nature, Vol 442, 291-294 P37 Magnetotellurics at the Central American Margin in Costa Rica and Nicaragua Mütschard, L., Brasse, H. P38 A permanent array of magnetotelluric stations located at the South American subduction zone in Northern Chile Dirk Brändlein1, Oliver Ritter1, Thomas Krings2, Ute Weckmann1,3

1 GFZ German Research Centre for Geosciences, Potsdam, Germany 2 University of Bremen, IUP, Bremen, Germany 3 University of Potsdam, Institute of Geosciences, Potsdam, Germany In order to monitor the dynamic behavior of an active deep subduction system, the GFZ Potsdam operates since 2006 a permanent array of combined geophysical and geodetic stations in Northern Chile called the Integrated Plate Boundary Observatory Chile (IPOC). Magnetotelluric data is recorded at seven out of eleven sites. The MT measurements are covered by three component long period fluxgate magnetometers

and Ag/AgCl electrodes measuring the two horizontal components of the electric field. EDL dataloggers are used to record data with a sampling rate of 20 Hz. The objective of the project is to continuously analyze electromagnetic data to decipher possible changes in the subsurface resistivity distribution, e.g. as a consequence of large scale fluid relocation. All seven MT stations are located in the Atacama Desert between the cities of Antofagasta and Iquique in Northern Chile. The extreme dry ground in this area causes huge problems to record the electric field continuously with sufficient data quality. Contact resistances in the order of several hundreds of kΩ up to more than one MΩ and electrodes with leaking electrolyte produce unstable time series of the electric field and thus scattered MT transfer functions. As the electrodes must be left in the ground unattended for several months, regular refilling is not possible. One year after the first deployment, dry electrodes were replaced by new ones which were coated in aluminum foil to prevent the electrolyte from leaking. Some months later these coated electrodes ran dry again because the reactive foil oxidized. In June 2009 the electrodes were replaced again, now with a modified coat. Within this presentation the new treble-coated electrodes are compared to the one-coated ones in terms of their data quality. The magnetic field data is of good quality. We show time series of vertical magnetic transfer functions over a time span of nearly two years from different sites and periods. These vertical magnetic field transfer function time series reveal interesting ultra long period variations which appear to be consistent over the array of sites. P39 Evolution of the crust and upper mantle structure beneath the Kunlun Shan in Northern Tibet from INDEPTH magnetotelluric data. Florian Le Pape1, Alan G. Jones 1, Jan Vozar 1 and the INDEPTH MT Team 1Dublin Institute for Advanced Studies, Dublin, Ireland During the INDEPTH (International Deep Profiling of Tibet and Himalaya) project Phase III surveys in 1999, broadband and long period magnetotelluric (MT) data were collected in Northern Tibet across the Kunlun Fault. The MT stations, placed along the northern part of the Lhasa to Golmud highway, defined the so-called 600-line profile extending from the middle of the Qiangtang Terrane to the southern edge of the Qaidam Basin. Previous inversions of the data from the 600-line, used the MT TE-mode, TM-mode and vertical magnetic field data to derive minimally smooth models. The final model obtained is characterized by a uniform mid-crustal conductor extending from the Kunlun Shan to the south end of the 600 profile and ending abruptly at the Kunlun Fault. North of the Kunlun Shan, the middle and lower crust, as well as the upper mantle, appear more resistive. As part of the new INDEPTH Phase IV, a new MT profile crossing again the Kunlun Shan, east of the 600-line, is planned to complement seismic data being acquired in the area. To introduce this coming survey, the 600-line data were re-analysed and re-modelled centring on the Kunlun Shan to focus on the shape of the resistivity changes beneath the Kunlun system in the crust and upper mantle. As an alternative to the previous studies, the models generated are more complex and exhibit greater lateral variability. The preliminary results, using all responses, highlight the changes in resistivity for the middle to lower crust, from conductive structures south to the Kunlun fault to resistive structures north to the fault. These lateral changes are representative of changing physical conditions, such as temperature or water content variability.

P40 Magnetotelluric data from the Tien Shan and Pamir continental collision zones, Central Asia. O. Ritter(1), A. Rybin(2), G. Muñoz(1), V. Batalev(2) (1) Helmholtz Centre Potsdam – GFZ, German Research Centre for Geosciences (2)Research Station of the Russian Academy of Sciences, Bishkek, Kyrgyzstan We present magnetotelluic (MT) data obtained within the framework of the multi-disciplinary Tien Shan – Pamir Geodynamic program (TIPAGE). The dynamics of the Tien Shan and Pamir orogenic belts are dominated by the collision of the Indian and Eurasian continental plates. With the geophysical components, we intend to image the deepest active intra-continental subduction zones on Earth (the N-dipping Hindu Kush and the S-dipping Pamir zones) and to establish how the highest strain over the shortest distance that is manifested in the India–Asia collision zone is accommodated structurally. The MT data were recorded in summer 2008 at 80 stations in the Pamir mountain ranges in Tajikistan and in summer 2009 at 98 stations the southern Tien Shan in Kyrgyzstan. A typical spacing was approximately 2 km between BB-only sites and 14 km for the combined BB+LMT sites. The stations form an approximately 340 km long profile from Osh in Kyrgyzstan via Sarytash, the Kyrgyz-Tajik border, Karakul and Murgab to Zorkul in southern Tajikistan. We present examples of the MT data, which is of exceptionally high quality in this very remote area, and show preliminary 2D inversion results.

Dienstag 29.9. – Diskussionsbeiträge (19:30 – 21:00) PW1 Hanstein, T. PW2 28 Jahre mit Peter Weidelt: Von der Betreuung der Diplomarbeit bis zu gemeinsamen Forschungsaufenthalten in Indien Tezkan, B. PW3 Konjugierte Gradienten Spitzer, K. PW4 Peter Weidelt’s Anisotropy Studies Pek, J. PW5 A direct inversion? Application of Propagation Number Analysis - in remembrance of Peter Weidelt Weckmann, U.

Mittwoch 30.9. – Diskussionsbeiträge (19:30 – 21:00) D1 Geophysikalischer Gerätepool Potsdam: Bedarf der Arbeitsgruppe ? Tezkan, B. D2 Permanente Remote Referenzstationen in Deutschland – eine konzertierte Aktion des AK EMTF? Ritter, O.

Donnerstag 1.10. – Diskussionsbeiträge (19:30 – 21:00) D3 Interpretation der magnetotellurischen Anisotropie: Ansätze nach Ulrich Schmucker Tezkan, B. D4 What I always wanted to know... Weckmann, U. D5 Geothermal exploration using MT and gravity techniques at Szentlırinc area in Hungary T. Hanstein*1, Z. X He3, I. M. Þorbergsdóttir2, K.-M. Strack1, and H. Tulinius2, and G. Yu1 1KMS Technolog.ies, Houston, TX, USA, 2Mannvit, Reykjavík, Iceland, and 3BGP, Hebei, Chin 2-D AMT/MT and gravity surveys were completed in 12 survey areas in Hungary during 2008. The main objective of this project was to locate potential geothermal targets for alternative energy development in Hungary. We selected here the Szentlırinc survey area because the first geothermal drilling project just completed. The main geothermal reservoir systems found in Hungary are the Mesozoic carbonate–karstic basement rocks and the Pliocene-Upper Pannonian porous sedimentary formations. The interpretation of 2-D AMT/MT and gravity focuses on locating potential geothermal areas of the geothermal reservoir system within Mesozoic fractured carbonate–karstic basement rock for drilling locations. We estimated that the faults within the north-south strike in the Szentlörinc survey area were developed in the deep basement. In addition, dense fractures have also been widely developed in the top basement (limestone) of the survey areas. Thermal energy, which was transported up along the fault systems from the deep Earth, seems to be the heat source of geothermal formation. A set of thick tertiary deposits, are located above the formation. Fractured karst limestone and dolomite deeply buried in the Mesozoic system contain the targeted geothermal reservoirs. Based on the cooperative constrained inversion of magnetotelluric (MT) and gravity data, we surmise that the geothermal aquifer is characterized by a relatively low apparent resistivity and low density, while the higher porosity and permeability formations are unique for faults and fractured zones. The distribution characteristics of the fault zones with relatively low resistivity and with boundaries outlined by cooperative constrained inversion of MT and gravity data indicate that the prospective zones for potential geothermal reservoirs in the Szentlörinc survey area indicate that the mid-northern part of AMT/MT line 1 and the middle part of AMT/MT line 2 are potential areas for geothermal power plants or space heating. The client has successfully drilled a well in Szentlörinc, Hungary using our exploration technology. Hot water of 80°C, estimated to have a peak heating capacity of 4 MW, was found at depths of 1,620 to 1,790 meters. This discovery was possible by utilizing different geophysical and geological information to determine the well location. The drilling was targeted by integrating electromagnetic and gravity methods with seismic and stratigraphic information.