Microseism Variations in Response to Antarctic Seasonal Changes in Sea Ice Extent

更新时间:2023-05-28

【摘要】The temporal and spatial distributions of Antarctic sea ice play important roles in both the generation mechanisms and the signal characteristics of microseisms. This link paves the way for seismological investigations of Antarctic sea ice. Here we present an overview of the current state of seismological research about microseisms on Antarctic sea ice. We first briefly review satellite remote-sensing observations of Antarctic sea ice over the past 50 years. We then systematically expound upon the generation mechanisms and source distribution of microseisms in relation to seismic noise investigations of sea ice, and the characteristics of Antarctic microseisms and relationship with sea ice variations are further analyzed. We also analyze the continuous data recorded at seismic station BEAR in West Antarctica from 2011 to 2018 and compare the microseism observations with the corresponding satellite remotesensing observations of Antarctic sea ice. Our results show that:(1) the microseisms from the coastal regions of West Antarctica exhibit clear seasonal variations,SFM with maximum intensities every April-May and minimum intensities around every October-November; while DFM intensities peak every February-March,and reach the minimum around every October. Comparatively,the strong seasonal periodicity of Antarctic sea ice in better agreement with the observed DFM; and(2) microseism decay is not synchronous with sea ice expansion since the microseism intensity is also linked to the source location,source intensity(e. g.,ocean storms,ocean wave field),and other factors. Finally, we discuss the effect of Southern Annular Mode on Antarctic sea ice and microseisms,as well as the current limitations and potential of employing seismological investigations to elucidate Antarctic sea ice variations and climate change.

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