Estimating volumes of capsizing iceberg : mechanical modeling of capsize constrained by seismic signals
International audience One main concern in climate science is to reduce uncertainties on sea level predictions. In particular,these uncertainties depend on the quantification of the mass losses of polar ice caps including Greenlandice sheet. Iceberg calving at Greenland glaciers accounts for up to h...
Main Authors: | , , , , , , , , |
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Other Authors: | , , , , , , , , , , , |
Format: | Conference Object |
Language: | French |
Published: |
HAL CCSD
2019
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Subjects: | |
Online Access: | https://hal.science/hal-02571877 https://hal.science/hal-02571877/document https://hal.science/hal-02571877/file/PaulineBonnet_Article_CFM_2019.pdf |
Summary: | International audience One main concern in climate science is to reduce uncertainties on sea level predictions. In particular,these uncertainties depend on the quantification of the mass losses of polar ice caps including Greenlandice sheet. Iceberg calving at Greenland glaciers accounts for up to half of ice losses at glacier termini.Some icebergs detaching from Greenland glaciers have the height of the glacier and are thin so unstableand capsize exerting a force on the glacier front which generates a seismic wave recorded at stationsin Greenland and further away. These seismic signals have been recorded for the last twenty-five yearsby the permanent stations. The number of such events has increased and the spatial distribution hasevolved. What is the evolution of the volume of capsizing icebergs ?Field data on capsizing icebergs are lacking, except for seismic data. Indeed, the database of seismicsignals gives continuous information about iceberg capsize events: we aim to extract information fromthese data. The characteristics of seismic signals depend on the iceberg volume and the whole dynamicof the capsizing iceberg [2]. The global aim of this work is to calculate the volum of capsizing icebergs.To do this, we compare recorded seismic signals to synthetic seismic signals calculated using a modelof iceberg capsize. Therefore, we solve an inverse problem to obtain information on the dynamic of thecapsize and in particular an estimation of the volume of the iceberg.Iceberg capsize dynamics depends on complex phenomena: iceberg-water interactions, iceberg-glacierfriction, glacier-sea floor friction, elasto-viscoplastic deformation of ice. Solving directly fluid flow, solidmotion, and contact equations even in two dimensions is very costly and can hardly be used to generatecatalogs and to solve inverse problem. Therefore, a simplified mechanical model of a capsizing icebergin water has been developed based on few assumptions. The proposed model, named SAFIM (semi-analytical floating iceberg model) accounts for ... |
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