Remote Triggering of Microseismicity at Mt. Erubus, Antarctica

Date: 4/26/2019

Time: 06:00 PM

Room: Grand Ballroom

Recent studies have found clear evidence of remotely triggered microseismicity at many active volcanoes during surface wave of large distant earthquakes. However, in many cases, triggered seismicity was only recorded by a single or a few seismic stations, making it difficult to locate the source and understand the triggering mechanism. Here we conduct a systematic search for remotely triggered seismicity at Mt. Erebus, Antarctica, using seismic data recorded by the permanent Mt. Erebus Volcano Observatory Seismic Network. Mt. Erebus is a heavily glaciated large stratovolcano on Ross Island, Antarctica. It is the southernmost active volcano on Earth and is adjacent to the US Antarctic McMurdo Station. With ongoing small-scale eruptions, a persistent lava lake, and long-term monitoring infrastructures, it is a natural laboratory to study volcanic processes and interactions between volcanoes, earthquakes and ice dynamics. So far we have found clear evidence of triggered seismicity at Mt. Erubus during the 2010 Mw 8.8 Maule, Chile earthquake. High-frequency seismic signals are recorded by multiple stations during the short-period Rayleigh waves of the Maule mainshock, suggesting that they are likely driven by dilatational stress perturbations. This behavior is similar to our recent observations triggered ice quakes at other stations in Antarctica during the Chile mainshock, and Erebus is known to host swarms of shallow near-summit ice quakes. However, it is not completely clear whether those triggered events at Mt. Erubus are associated with magma, tectonic, or ice movements. Our next step is to accurately locate those remotely triggered events, and compare them with background cryo- and volcanic seismicity to better understand their source locations and triggering mechanism. In addition, we plan to conduct a systematic search for other remotely triggered seismicity in the Mount Erebus region to constrain the triggering threshold and necessary conditions.

Presenting Author: Zhigang Peng

Authors