Seismic full-wavefield imaging of the West Antarctic Ice Sheet interior near the ice flow divide

Zhang，Zhendong1,2; Nakata，Nori2,3; Karplus，Marianne4; Kaip，Galen4; Qin，Lei5; Li，Zhengbo6; Shi，Caiwang6; Chen，Xiaofei6

2024-06-15

10.1016/j.epsl.2024.118701

Earth and Planetary Science Letters   影响因子和分区

0012-821X

The properties and behavior of the West Antarctic Ice Sheet through time are key to understanding climate and sea level change in the near future. We analyze different types of seismic waves from an active-source acquisition deployed on the West Antarctic Ice Sheet and uncover the internal structures of the ice sheet using seismic imaging methods. Surface waves including leaky and normal modes are separated from englacial and bed reflections using a cross-component matched filter method. Leaky modes are uniquely strong in the data possibly due to the firn layer and ice compaction. We use a joint inversion of leaky and normal surface waves for P- and S-wave velocity estimation in the near-surface and attribute the ultra-low Vp and Vs ratios to the pore closure. We observe englacial reflections down to 50 Hz and bed reflections with multiple branches. Such reflection waves are further used to calculate the seismic images of discontinuities in the ice sheet and the bedrock, revealing multiple layers within the ice near the bed and a heterogeneous bedrock with a rugged surface and possibly existing faults. The fine structure of the ice sheet revealed by seismic data helps with searching for possible drain points and evaluating the instability of the ice sheet. Our data analysis shown in the study is also applicable to typical data sets collected for critical zone exploration.

englacial reflections leaky modes seismic imaging West Antarctica

英语

NI期刊

其他

GEOSCIENCES

2-s2.0-85190348289

Scopus

1.Key Laboratory of Deep Petroleum Intelligent Exploration and Development,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing,100029,China
2.Department of Earth,Atmospheric and Planetary Sciences,Massachusetts Institute of Technology,Cambridge,02139,United States
3.Energy Geosciences Division,Lawrence Berkeley National Laboratory,Berkeley,94720,United States
4.Department of Earth,Environmental and Resource Sciences,University of Texas at El Paso,El Paso,79968,United States
5.School of Geophysics and Geomatics,China University of Geosciences,Hubei,430074,China
6.Department of Earth and Space Sciences,Southern University of Science and Technology,Shenzhen,518055,China

Zhang，Zhendong,Nakata，Nori,Karplus，Marianne,et al. Seismic full-wavefield imaging of the West Antarctic Ice Sheet interior near the ice flow divide[J]. Earth and Planetary Science Letters,2024,636.

Zhang，Zhendong.,Nakata，Nori.,Karplus，Marianne.,Kaip，Galen.,Qin，Lei.,...&Chen，Xiaofei.(2024).Seismic full-wavefield imaging of the West Antarctic Ice Sheet interior near the ice flow divide.Earth and Planetary Science Letters,636.

Zhang，Zhendong,et al."Seismic full-wavefield imaging of the West Antarctic Ice Sheet interior near the ice flow divide".Earth and Planetary Science Letters 636(2024).