Backprojection of volcanic tremor
Backprojection of volcanic tremor
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DOI：
10.1002/2013gl058836
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发表时间：
2014-03
影响因子：
5.2
通讯作者：
M. Haney
中科院分区：
文献类型：
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作者：
M. Haney
反投影已成为对全球地震破裂过程进行成像的有力工具。我们还展示了反投影照明和跟踪火山源的能力。我们将该方法应用于阿拉斯加奥克莫克火山 2008 年喷发期间震动升级时的地震网络。尽管我们能够将波场聚焦到活动锥体的位置附近，但网络阵列响应缺乏足够的分辨率来揭示震动位置的公里级变化。通过对连续反投影图像中的响应进行去卷积，我们提高了分辨率，并发现震源在升级之前向破火山口内湖移动。因此，增加的震颤是由岩浆-水相互作用引起的，与喷发的整体岩浆特征一致。喷发震颤的成像表明，时间反演方法（例如反投影）可以为火山源的时间演化提供新的见解。
Backprojection has become a powerful tool for imaging the rupture process of global earthquakes. We demonstrate the ability of backprojection to illuminate and track volcanic sources as well. We apply the method to the seismic network from Okmok Volcano, Alaska, at the time of an escalation in tremor during the 2008 eruption. Although we are able to focus the wavefield close to the location of the active cone, the network array response lacks sufficient resolution to reveal kilometer‐scale changes in tremor location. By deconvolving the response in successive backprojection images, we enhance resolution and find that the tremor source moved toward an intracaldera lake prior to its escalation. The increased tremor therefore resulted from magma‐water interaction, in agreement with the overall phreatomagmatic character of the eruption. Imaging of eruption tremor shows that time reversal methods, such as backprojection, can provide new insights into the temporal evolution of volcanic sources.