资源环境科技发展态势分析平台

Ambient noise interferometry has become an increasingly popular tool for monitoring active volcanoes. We apply this method to investigate seven past eruptive periods at Veniaminof volcano, Alaska. Two of the largest eruptions studied show seismic velocity changes associated with preeruptive, coeruptive, and posteruptive volcanic processes. We develop and implement new analysis techniques to determine how seismic velocity changes at Veniaminof are distributed with depth. Spatiotemporal examination of these seismic velocity changes reveals evidence for the distribution of magma storage and the timescale at which magmatic fluids intrude into and reside within these storage regions in the months preceding eruption. We conduct the depth analysis using data recorded on a single seismometer. The same analysis could be applied to any volcano monitored by at least one seismometer in order to detect magmatic activity indicative of impending eruption, specifically the intrusion and migration of magmatic fluids into the volcanic system.

Plain Language Summary Veniaminof is one of the most active volcanoes in Alaska. Eruptions at the volcano occur frequently and can begin with little to no warning. In this study, we explore new and emerging seismic methods for identifying magmatic activity indicative of eruption. First, we apply the technique of ambient noise interferometry to determine subtle changes in seismic velocity within Veniaminof's subsurface. Such changes in seismic velocity indicate the movement of magmatic fluids into the volcanic system as early as weeks to months prior to the start of the two largest eruptions examined. In the second part of our study, we develop new techniques to determine changes in seismic velocity as a function of both depth and time. This analysis provides evidence for the timescales and depths at which magmatic fluids migrate through and are stored within the crust preceding eruption at Veniaminof. In order to carry out this spatiotemporal analysis, we utilize seismic data recorded on a single seismometer. Thus, the same analysis could be applied at any volcano monitored by even a single seismometer in an effort to identify the intrusion, migration, and storage of magmatic fluids in the time leading to eruption.