USAP-DC

The continent of Antarctica has approximately the same surface area as the continental United States, though we know significantly less about its underlying geology and seismic activity. Multinational investments in geophysical infrastructure over the last few decades, especially broadband seismometers operating for several years, are allowing us to observe many interesting natural phenomena, including iceberg calving, ice stream slip, and tectonic earthquakes. To specifically leverage those past investments, we will analyze past and current data to gain a better understanding of Antarctic seismicity. Our recent research revealed that certain large earthquakes occurring elsewhere in the world triggered ice movement near various stations throughout Antarctica. We plan to conduct an exhaustive search of the terabytes of available data, using cutting-edge computational techniques, to uncover additional evidence for ice crevassing, ice stream slip, and earth movement during earthquakes. One specific focus of our research will include investigating whether some of these phenomena may be triggered by external influences, including passing surface waves from distant earthquakes, ocean tides, or seasonal melt. We plan to produce a catalog of the identified activity and share it publicly, so the public and researchers can easily access it. To reach a broader audience, we will present talks to high school classes, including Advanced Placement classes, in the Austin, Texas and Atlanta, Georgia metropolitan areas with emphasis on general aspects of seismic hazard, climate variability, and the geographies of Antarctica. This project will provide research opportunities for undergraduates, training for graduate students, and support for an early-career scientist. In recent years, a new generation of geodetic and seismic instrumentation has been deployed as permanent stations throughout Antarctica (POLENET), in addition to stations deployed for shorter duration (less than 3 years) experiments (e.g. AGAP/TAMSEIS). These efforts are providing critical infrastructure needed to address fundamental questions about both crustal-scale tectonic structures and ice sheets, and their interactions. We plan to conduct a systematic detection of tectonic and icequake activities in Antarctica, focusing primarily on background seismicity, remotely-triggered seismicity, and glacier slip events. Our proposed tasks include: (1) Identification of seismicity throughout the Antarctic continent for both tectonic and ice sources. (2) An exhaustive search for additional triggered events in Antarctica during the last ~15 years of global significant earthquakes. (3) Determination of triggered source mechanisms and whether those triggered events also occur at other times, by analyzing years of data using a matched-filter analysis (where the triggered local event is used to detect similar events). (4) Further analysis of GPS measurements over a ~5.5 year period from Whillans Ice Plain, which suggests that triggering of stick-slip events occurred after the largest earthquakes. An improved knowledge of how the Antarctic ice sheet responds to external perturbations such as dynamic stresses from large distant earthquakes and recent ice unloading could lead to a better understanding of ice failure and related dynamic processes. By leveraging the vast logistical investment to install seismometers in Antarctica over the last decade, our project will build an exhaustive catalog of tectonic earthquakes, icequakes, calving events, and any other detectable near-surface seismic phenomena.

Person	Role
Walter, Jacob	Investigator and contact
Peng, Zhigang	Co-Investigator

Antarctic Earth Sciences	Award # 1745135
Antarctic Earth Sciences	Award # 1543399
Antarctic Earth Sciences	Award # 1543286

USAP-1745135_1

Data_Management_Plan_2015.doc

1. Li, C., Z. Peng, J. A. Chaput, J. I. Walter, and R. C. Aster (2021), Remote Triggering of Icequakes at Mt. Erebus, Antarctica by Large Teleseismic Earthquakes, Seismol. Res. Lett. (doi:10.1785/0220210027)
2. Neves, M., Custódio, S., Peng, Z., & Ayorinde, A. (2017). Earthquake triggering in southeast Africa following the 2012 Indian Ocean earthquake. Geophysical Journal International, 212(2), 1331–1343. (doi:10.1093/gji/ggx462)
3. Bansal, A. R., Rao, N. P., Peng, Z., Shashidhar, D., & Meng, X. (2018). Remote Triggering in the Koyna-Warna Reservoir-Induced Seismic Zone, Western India. Journal of Geophysical Research: Solid Earth, 123(3), 2318–2331. (doi:10.1002/2017jb014563)
4. Walter, J. I., P. Ogwari, A. Thiel, Fernando Ferrer, and I. Woelfel (2021). easyQuake: putting machine learning to work for your regional seismic network or local earthquake study, Seismological Research Letter, https://doi.org/10.1785/0220200226.