The influence of Moho depth on the seismic / density structure of the Antarctic upper mantle

With its hostile and remote environment, information on Antarctica’s geologic history and its internal geophysical structure remains today the most incomplete on Earth. In particular, Moho depth estimate studies are in disagreement by more than 10 km in several regions and, the Antarctic upper mantl...

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Bibliographic Details
Main Authors: Tondi, R., Borghi, A., Morelli, A.
Format: Conference Object
Language:English
Published: 2023
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Online Access:https://gfzpublic.gfz-potsdam.de/pubman/item/item_5017901
Description
Summary:With its hostile and remote environment, information on Antarctica’s geologic history and its internal geophysical structure remains today the most incomplete on Earth. In particular, Moho depth estimate studies are in disagreement by more than 10 km in several regions and, the Antarctic upper mantle remains among the most poorly imaged regions in the Earth. In this study, we explore the impact of using different Moho surfaces on the reconstruction of the 3D density and velocity parameters beneath the Antarctic continent. To achieve this goal we selected as input for the used optimization algorithm (Sequential Integrated Inversion, Tondi et al., 2012) four Moho depth estimates, which we believe to be the most representative of the last studies on the continent: (a) a pure gravimetric Moho (Borghi, 2022); (b) a depth to Moho (Baranov et al., 2018) recovered using the BEDMAP2 subglacial relief (Fretwell et al., 2013) together with results from the analysis of recent seismic data (Baranov and Morelli, 2013; Chaput et al., 2014) and gravity constraints; (c) a seismological Moho (An et al., 2015); (d) a Moho depth estimate constrained by both satellite gravity and seismological information (Pappa et al., 2019). To complete the starting information, we exploited: (1) the surface wave tomography of the Antarctic upper mantle (Danesi and Morelli, 2001) and (2) the gravity database synthetized by the global satellite gravity model GO_CONS_GCF_2_TIM_R6e (Zingerle et al., 2019). Results show the crucial implications of the Moho topography on the recovered geophysical parameters, especially in little explored areas.