Patanè D, Barberi G, Cocina O, De Gori P, Chiarabba C
Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, Piazza Roma, 2, 95123, Catania, Italy.
Science. 2006 Aug 11;313(5788):821-3. doi: 10.1126/science.1127724.
The continuous volcanic and seismic activity at Mount Etna makes this volcano an important laboratory for seismological and geophysical studies. We used repeated three-dimensional tomography to detect variations in elastic parameters during different volcanic cycles, before and during the October 2002-January 2003 flank eruption. Well-defined anomalous low P- to S-wave velocity ratio volumes were revealed. Absent during the pre-eruptive period, the anomalies trace the intrusion of volatile-rich (>/=4 weight percent) basaltic magma, most of which rose up only a few months before the onset of eruption. The observed time changes of velocity anomalies suggest that four-dimensional tomography provides a basis for more efficient volcano monitoring and short- and midterm eruption forecasting of explosive activity.
埃特纳火山持续的火山活动和地震活动使其成为地震学和地球物理学研究的重要实验室。我们利用重复三维层析成像技术，在2002年10月至2003年1月侧翼喷发之前和期间的不同火山活动周期内，检测弹性参数的变化。结果揭示了明确的低P波与S波速度比异常区域。这些异常在喷发前阶段并不存在，它们追踪了富含挥发物（≥4重量百分比）的玄武质岩浆的侵入，其中大部分岩浆在喷发开始前几个月才上升。观测到的速度异常随时间的变化表明，四维层析成像为更有效地监测火山以及对爆炸性活动进行短期和中期喷发预测提供了依据。
