Linking magma transport structures at Kīlauea volcano
Linking magma transport structures at Kīlauea volcano
复制标题
连接基拉韦厄火山的岩浆输送结构
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
W. Thelen
中科院分区：
文献类型：
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作者：
A. Wech;W. Thelen
确定岩浆路径对于理解和解释火山信号很重要。在KīLauea火山，地震活动照亮了地下管道，但广泛的地震现象阻碍了事件的识别。离散的长周期(LP)事件在浅层(5-10 公里)管道中占主导地位，在近海观察到深层次(40+ 公里)的地震。然而，我们无法常规地识别这些事件，限制了它们在追踪上升岩浆方面的作用。利用包络互相关法，系统地编目了2008-2014年间的非地震活动。我们发现LP和深震在空间上是不同的，被15-25 公里深的水平地幔断裂带隔开。我们的研究证实了之前的观察结果，但我们发现了由并置地震组成的更宽频段(0.520 HZ)的地震，并将深部地震重新解释为围绕着MFZ下地幔岩浆侵入并对其做出反应的体积中的地震群。我们认为，上覆的MFZ促进了岩浆的横向运移，将这种深部侵入体与Kī劳埃亚的浅层岩浆管道联系在一起。
Identifying magma pathways is important for understanding and interpreting volcanic signals. At Kīlauea volcano, seismicity illuminates subsurface plumbing, but the broad spectrum of seismic phenomena hampers event identification. Discrete, long‐period (LP) events dominate the shallow (5–10 km) plumbing, and deep (40+ km) tremor has been observed offshore. However, our inability to routinely identify these events limits their utility in tracking ascending magma. Using envelope cross‐correlation, we systematically catalog non‐earthquake seismicity between 2008 and 2014. We find that the LPs and deep tremor are spatially distinct, separated by the 15–25 km deep, horizontal mantle fault zone (MFZ). Our search corroborates previous observations, but we find broader band (0.5–20 Hz) tremor comprising collocated earthquakes and reinterpret the deep tremor as earthquake swarms in a volume surrounding and responding to magma intruding from the mantle plume beneath the MFZ. We propose that the overlying MFZ promotes lateral magma transport, linking this deep intrusion with Kīlauea's shallow magma plumbing.