Decompensative gravity anomalies reveal structure of the upper crust of Antarctica
Despite a big progress in the study of the Antarctic ice shield, still little is known about the structure of the uppercrust including sedimentary basins, which are hidden under the ice. In this work, we infer density heterogeneityof the upper crust of Antarctica by computing decompensative anomalie...
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_4504891 2023-05-15T13:35:25+02:00 Decompensative gravity anomalies reveal structure of the upper crust of Antarctica Kaban, M. Haeger, C. 2019 https://gfzpublic.gfz-potsdam.de/pubman/item/item_4504891 eng eng https://gfzpublic.gfz-potsdam.de/pubman/item/item_4504891 Geophysical Research Abstracts Vol. 21, EGU2019-15435, 2019 info:eu-repo/semantics/conferenceObject 2019 ftgfzpotsdam 2022-09-14T05:56:46Z Despite a big progress in the study of the Antarctic ice shield, still little is known about the structure of the uppercrust including sedimentary basins, which are hidden under the ice. In this work, we infer density heterogeneityof the upper crust of Antarctica by computing decompensative anomalies of the gravity field. These anomaliesare based on the isostatic anomalies, which are initially computed using the observed gravity field (satellite andterrestrial models), basement topography, ice thickness provided by the Bedmap2 project (Fretwell et al., 2013)and bathymetry of the surrounding ocean. In the isostatic model, we have also taken into account variations ofthe effective elastic thickness of the lithosphere and Moho depth from previous studies. Although the isostaticanomalies chiefly reflect the upper crust density heterogeneities, their impact is substantially reduced by isostaticcompensation. To refine this effect from the deep sources, we applied a so-called decompensative correction(Kaban et al., 2017). Therefore, the computed decompensative gravity anomalies are most appropriate to study theupper crust density structure. The obtained decompensative anomalies well correspond to the known sedimentarybasins, such as in the areas of the Filchner-Ronne Ice Shelf and Lambert Graben, however they suggest theexistence of other large sedimentary deposits both in West and East Antarctica, which are not yet revealed due toa lack of seismic surveys. The extended positive anomaly in East Antarctica is likely related to the old and densecratonic crust. Conference Object Antarc* Antarctic Antarctica East Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Shelf Ronne Ice Shelf GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Antarctic East Antarctica Kaban ENVELOPE(158.700,158.700,52.967,52.967) Ronne Ice Shelf ENVELOPE(-61.000,-61.000,-78.500,-78.500) The Antarctic |
institution |
Open Polar |
collection |
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
English |
description |
Despite a big progress in the study of the Antarctic ice shield, still little is known about the structure of the uppercrust including sedimentary basins, which are hidden under the ice. In this work, we infer density heterogeneityof the upper crust of Antarctica by computing decompensative anomalies of the gravity field. These anomaliesare based on the isostatic anomalies, which are initially computed using the observed gravity field (satellite andterrestrial models), basement topography, ice thickness provided by the Bedmap2 project (Fretwell et al., 2013)and bathymetry of the surrounding ocean. In the isostatic model, we have also taken into account variations ofthe effective elastic thickness of the lithosphere and Moho depth from previous studies. Although the isostaticanomalies chiefly reflect the upper crust density heterogeneities, their impact is substantially reduced by isostaticcompensation. To refine this effect from the deep sources, we applied a so-called decompensative correction(Kaban et al., 2017). Therefore, the computed decompensative gravity anomalies are most appropriate to study theupper crust density structure. The obtained decompensative anomalies well correspond to the known sedimentarybasins, such as in the areas of the Filchner-Ronne Ice Shelf and Lambert Graben, however they suggest theexistence of other large sedimentary deposits both in West and East Antarctica, which are not yet revealed due toa lack of seismic surveys. The extended positive anomaly in East Antarctica is likely related to the old and densecratonic crust. |
format |
Conference Object |
author |
Kaban, M. Haeger, C. |
spellingShingle |
Kaban, M. Haeger, C. Decompensative gravity anomalies reveal structure of the upper crust of Antarctica |
author_facet |
Kaban, M. Haeger, C. |
author_sort |
Kaban, M. |
title |
Decompensative gravity anomalies reveal structure of the upper crust of Antarctica |
title_short |
Decompensative gravity anomalies reveal structure of the upper crust of Antarctica |
title_full |
Decompensative gravity anomalies reveal structure of the upper crust of Antarctica |
title_fullStr |
Decompensative gravity anomalies reveal structure of the upper crust of Antarctica |
title_full_unstemmed |
Decompensative gravity anomalies reveal structure of the upper crust of Antarctica |
title_sort |
decompensative gravity anomalies reveal structure of the upper crust of antarctica |
publishDate |
2019 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_4504891 |
long_lat |
ENVELOPE(158.700,158.700,52.967,52.967) ENVELOPE(-61.000,-61.000,-78.500,-78.500) |
geographic |
Antarctic East Antarctica Kaban Ronne Ice Shelf The Antarctic |
geographic_facet |
Antarctic East Antarctica Kaban Ronne Ice Shelf The Antarctic |
genre |
Antarc* Antarctic Antarctica East Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Shelf Ronne Ice Shelf |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Filchner Ronne Ice Shelf Filchner-Ronne Ice Shelf Ice Shelf Ronne Ice Shelf |
op_source |
Geophysical Research Abstracts Vol. 21, EGU2019-15435, 2019 |
op_relation |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_4504891 |
_version_ |
1766065364075020288 |