Alaska Volcano Observatory, Wilson Alaska Technical Center, Geophysical Institute, University of Alaska Fairbanks, 903 Koyukuk Drive, Fairbanks, AK 99775, USA.
Alaska Volcano Observatory, U.S. Geological Survey, 4230 University Drive, Anchorage, AK 99508, USA.
Science. 2017 Jan 6;355(6320):45-48. doi: 10.1126/science.aah6108.
The March 2016 eruption of Pavlof Volcano, Alaska, produced an ash plume that caused the cancellation of more than 100 flights in North America. The eruption generated strong tremor that was recorded by seismic and remote low-frequency acoustic (infrasound) stations, including the EarthScope Transportable Array. The relationship between the tremor amplitudes and plume height changes considerably between the waxing and waning portions of the eruption. Similar hysteresis has been observed between seismic river noise and discharge during storms, suggesting that flow and erosional processes in both rivers and volcanoes can produce irreversible structural changes that are detectable in geophysical data. We propose that the time-varying relationship at Pavlof arose from changes in the tremor source related to volcanic vent erosion. This relationship may improve estimates of volcanic emissions and characterization of eruption size and intensity.
2016 年 3 月，阿拉斯加帕夫洛夫火山喷发，形成的火山灰羽流导致北美超过 100 次航班取消。这次喷发产生了强烈的震动，被包括 EarthScope 可移动阵列在内的地震和远程低频声学（次声）台站记录下来。在喷发的渐强和渐弱阶段，震动幅度与羽流高度之间的关系变化很大。在风暴期间，地震河噪与流量之间也观察到类似的滞后现象，这表明河流和火山中的流动和侵蚀过程都会产生可在地球物理数据中检测到的不可逆结构变化。我们提出，帕夫洛夫火山的这种时变关系源于与火山喷口侵蚀有关的震动源变化。这种关系可能会改进对火山喷发排放物的估算以及对喷发规模和强度的描述。
