Direct observation of a submarine volcanic eruption from a sea-floor instrument caught in a lava flow
Direct observation of a submarine volcanic eruption from a sea-floor instrument caught in a lava flow
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DOI：
10.1038/35089066
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发表时间：
2001-08-16
期刊：
影响因子：
64.8
通讯作者：
Embley, RW
中科院分区：
文献类型：
--
作者：
Fox, CG;Chadwick, WW;Embley, RW
过去十年来，我们对海底火山爆发的了解有了很大提高，因为最近有能力对这种事件进行遥感探测（1），然后在爆发地点进行天气调查和取样，迅速作出反应。但这些数据必然仅限于事件发生后的观察（2）。相反，1998年胡安德富卡海脊上的Axial火山喷发（3、4）是由现场海底仪器监测的（5-7）。其中一个测量海底压力作为海底垂直变形的代理的仪器被1998年的熔岩流淹没和困住。仪器幸存下来--被凝固的地壳与熔融的熔岩隔离--后来被回收。该仪器偶然记录的数据揭示了大洋中脊片流喷发的持续时间、特征和渗出率，并记录了三米多的熔岩流膨胀和随后的回流。在短暂的两小时喷发后，该仪器还测量到在接下来的几天里逐渐下沉了1.4米，这反映了随着岩浆进入邻近的裂谷带，整个火山山顶都在收缩。这些发现与我们以前从海底观测、陆地模拟和实验室模拟中推断出的海底熔岩喷发的理解是一致的（8-11）。
Our understanding of submarine volcanic eruptions has improved substantially in the past decade owing to the recent ability to remotely detect such events(1) and to then respond rapidly with synoptic surveys and sampling at the eruption site. But these data are necessarily limited to observations after the event(2). In contrast, the 1998 eruption of Axial volcano on the Juan de Fuca ridge(3,4) was monitored by in situ sea-floor instruments(5-7). One of these instruments, which measured bottom pressure as a proxy for vertical deformation of the sea floor, was overrun and entrapped by the 1998 lava flow. The instrument survived- being insulated from the molten lava by the solidified crust- and was later recovered. The data serendipitously recorded by this instrument reveal the duration, character and effusion rate of a sheet flow eruption on a mid-ocean ridge, and document over three metres of lava-flow inflation and subsequent drain-back. After the brief two-hour eruption, the instrument also measured gradual subsidence of 1.4 metres over the next several days, reflecting deflation of the entire volcano summit as magma moved into the adjacent rift zone. These findings are consistent with our understanding of submarine lava effusion, as previously inferred from seafloor observations, terrestrial analogues, and laboratory simulations(8-11).