Department or Administrative Unit
We observe two (~MS 3) long‐period (10–30 s) seismic events that originate from the terminus of Thwaites Glacier, Antarctica. Serendipitous acquisition of satellite images confirm that the seismic events were glacial earthquakes generated during the capsizing of icebergs. The glacial earthquakes were preceded by 6 days of discrete high‐frequency seismic events that can be observed at distances exceeding 250 km. The high‐frequency seismicity displays an increasing rate of occurrence, culminating in several hours of sustained tremor coeval with the long‐period events. A series of satellite images collected during this precursory time period show that the high‐frequency events and tremor are the result of accelerating growth of ancillary fractures prior to the culminating calving event. This study indicates that seismic data have the potential to elucidate the processes by which Thwaites Glacier discharges into the ocean, thus improving our ability to constrain future sea level rise.
Winberry, J. P., Huerta, A. D., Anandakrishnan, S., Aster, R. C., Nyblade, A. A., & Wiens, D. A. (2020). Glacial earthquakes and precursory seismicity associated with Thwaites Glacier calving. Geophysical Research Letters, 47, e2019GL086178. https://doi.org/10.1029/2019GL086178
Geophysical Research Letters
©2020. American Geophysical Union. All Rights Reserved.
This article was originally published in Geophysical Research Letters. The full-text article from the publisher can be found here.