The Transcrustal Magma Reservoir Beneath Soufrière Hills Volcano, Montserrat: Insights From 3-D Geodetic Inversions
The Transcrustal Magma Reservoir Beneath Soufrière Hills Volcano, Montserrat: Insights From 3-D Geodetic Inversions
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蒙特塞拉特苏弗里埃尔山火山下的跨地壳岩浆储层：来自 3-D 大地测量反演的见解
DOI：
10.1029/2020gl089239
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发表时间：
2020
影响因子：
5.2
通讯作者：
Gottsmann J
中科院分区：
文献类型：
--
作者：
Gottsmann J
我们反转2003年和2005年之间记录的蒙特塞拉特火山内部地面位移，揭示苏弗里耶尔山火山的岩浆管道系统。在有限元模型中对三维地壳力学和地形数据进行了分析，我们发现，记录的位移最好用一个向东南倾斜（倾伏角为9.3°）的垂直延伸的三轴椭球压力源来解释，其水平半轴长度为1.9和2.0 km，垂直半轴长度为5.0 km。震源集中在主海平面以下9.35公里深处，并嵌入独立成像的异常脆弱的地壳岩石中。震源方向似乎受两个主要WNW-ESE和NW-SE走向构造线性构造交汇处的局部应力场控制。我们得到的平均体积应变率为8.4 × 10− 12 s − 1的穿壳增压，这可能有助于侧翼不稳定和质量浪费事件在南部和东部的岛屿。
We invert intraeruptive ground displacements recorded between 2003 and 2005 on Montserrat to shed light on the magmatic plumbing system of Soufrière Hills Volcano. Incorporating 3‐dimensional crustal mechanical and topographic data in a finite‐element model, we show that the recorded displacements are best explained by a southeastward dipping (plunge angle of 9.3°) vertically extended triaxial ellipsoidal pressure source with semiaxes lengths of 1.9 and 2.0 km horizontally, and 5.0 km vertically. The source is centered at 9.35 km depth below main sea level and embedded in independently imaged anomalously weak crustal rocks. The source orientation appears to be controlled by the local stress field at the intersection of two major WNW‐ESE and NW‐SE striking tectonic lineaments. We derive an average volumetric strain rate of 8.4 × 10−12s−1by transcrustal pressurization which may have contributed to flank instability and mass wasting events in the southern and eastern sectors of the island.