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(1)

Development of a 3-D Crustal Model

in the Western Dronning Maud Land Region, Antarctica, from the Interpretation of different geophysical data sets

M. Hoffmann, A. Eckstaller, W. Jokat, H. Miller

(2)

• Introduction into the region

• Available data sets

• seismic surveys

• seismolgical data

• airborne gravity and magnetic data

• Receiver Function Analysis

• Development of a 3D crustal model

• Outlook

Outline

(3)

Introduction

Gondwana Reconstruction at c. 1 Ga Heimefrontfjella Shear Zone

(both figures after J. Jacobs)

(4)

Heimefront Shear Zone up to 20 km wide, vertical, dextral transpression zone

Foto: J. Jacobs

(5)

• refraction and

reflection seismic data

• permanent installed seismometer stations

• temporarily installed seismometer stations

Available Data Sets

(6)

• Aerogravity

• Aeromagnetics

• EMR Radar (ice thickness) Available Data Sets

Flight Lines in CDML

(data partly processed)

(7)

Interpretation of Seismic Profiles from western Dronning Maud Land

Kudryavtzev 1989

(8)

Interpretation of Seismic Profiles from western Dronning Maud Land

SAE 33 - Kudryavtzev 1989

(9)

Interpretation of Seismic Profiles from western Dronning Maud Land

Kudryavtzev 1989

(10)

Interpretation of Seismic Profiles from western Dronning Maud Land

SAE 34 - Kudryavtzev 1989

(11)

Interpretation of Seismic Profiles from western Dronning Maud Land

Kudryavtzev 1989

(12)

Interpretation of Seismic Profiles from western Dronning Maud Land

Kottas Profil – A. Eckstaller 1989/90

(13)

Interpretation of Seismic Profiles from western Dronning Maud Land

Kudryavtzev 1989

(14)

Interpretation of Seismic Profiles from western Dronning Maud Land

Hungeling & Thyssen 1985/1986

(15)

Seismological Data

Receiver Function Studies

• problem at stations

on ice: large reverberations hide weak Moho conversions

• use of simple models based on seismic interpretations

(16)

Receiver Function Analysis

Station 9170, ice thickness 850 m

Station 9172, ice thickness 1569 m

(17)

Receiver Function Analysis

Station 9173, ice thickness 1075 m

Station 9169, ice thickness 2075 m

(18)

Obtained Moho Depth 32

33

32

35 38

41

35

45 43 ? 50

48 44 37

43

50 Moho depth in km

• results from seismological and seismic studies

• spatial distribution

• seismic and seismological results show similar Moho depths

(19)

First Attempt to

gridd the Moho Depth

30 35 40 45 50 55

km

?

?

?

? ?

?

?

?

(20)

Discussion & Outlook

• Receiver Function studies show similiar results like the results obtained from seismic data

• the results show, that the Heimefrontfjella shear zone is also a boundary in terms of crustal evolution

• a denser data distribution for obtaining the Moho depth and the use of aeromagnetic and aerogravity Data leads to a proper 3D Model

• enhanced Receiver Function Analysis in combination with Shear Wave Splitting investigations will give more detailled results

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