US Geological Survey, Menlo Park, California 94025, USA.
Nature. 2011 Oct 19;478(7369):374-7. doi: 10.1038/nature10541.
Rhyolite is the most viscous of liquid magmas, so it was surprising that on 2 May 2008 at Chaitén Volcano, located in Chile's southern Andean volcanic zone, rhyolitic magma migrated from more than 5 km depth in less than 4 hours (ref. 1) and erupted explosively with only two days of detected precursory seismic activity. The last major rhyolite eruption before that at Chaitén was the largest volcanic eruption in the twentieth century, at Novarupta volcano, Alaska, in 1912. Because of the historically rare and explosive nature of rhyolite eruptions and because of the surprisingly short warning before the eruption of the Chaitén volcano, any information about the workings of the magmatic system at Chaitén, and rhyolitic systems in general, is important from both the scientific and hazard perspectives. Here we present surface deformation data related to the Chaitén eruption based on radar interferometry observations from the Japan Aerospace Exploration Agency (JAXA) DAICHI (ALOS) satellite. The data on this explosive rhyolite eruption indicate that the rapid ascent of rhyolite occurred through dyking and that melt segregation and magma storage were controlled by existing faults.
流纹岩是粘性最大的液态岩浆，因此 2008 年 5 月 2 日位于智利南部安第斯火山区的柴滕火山的流纹岩浆在不到 4 小时内从 5 公里深处迁移出来，并发生了爆炸性喷发，而此前仅检测到两天的地震活动前兆，这令人惊讶。在柴滕火山喷发之前，上一次主要的流纹岩喷发是 1912 年阿拉斯加诺瓦鲁普塔火山的 20 世纪最大火山喷发。由于流纹岩喷发在历史上罕见且具有爆炸性，而且柴滕火山喷发前的预警时间非常短，因此任何有关柴滕火山岩浆系统以及一般流纹岩系统运作的信息，从科学和灾害角度来看都非常重要。在这里，我们根据日本宇宙航空研究开发机构（JAXA）的 DAICHI（ALOS）卫星的雷达干涉测量观测，提供了与柴滕火山喷发有关的地表变形数据。这次对爆发性流纹岩喷发的观测表明，流纹岩浆的快速上升是通过岩脉作用产生的，而熔体分离和岩浆储存则受到现有断层的控制。
