美国耶鲁大学Jonathan Wolf团队最近的研究揭示了强地震各向异性是由于黄石地幔柱根部的上升流引发的。相关论文于2024年3月1日发表在《地质学》杂志上。

据研究人员介绍，地震各向异性通常是由形变引起的，可以用来识别和表征地幔流。研究表明，地幔底部的地幔柱根位置具有强烈的地震各向异性。这一发现得到了地球动力学模拟结果的补充，该模拟结果显示，黄石地区地下最下层的地幔存在上升流和高应变。

该研究结果也支持了这一观点，即黄石火山活动是由植根于南加州最深处地幔柱所主导的，它将最深处地幔的动态与地球表面的现象联系起来。

据悉，黄石地区(美国西部)是一个经常被引用的板块内火山活动的例子，几十年来，其起源一直是备受争论的话题。最近的研究表明，植根于南加州地下的深层地幔柱是黄石火山活动的源头。

附：英文原文

Title: Strong seismic anisotropy due to upwelling flow at the root of the Yellowstone mantle plume

Author: Jonathan Wolf, Mingming Li, Anne A. Haws, Maureen D. Long

Issue&Volume: 2024-03-01

Abstract: The Yellowstone region (western United States) is a commonly cited example of intraplate volcanism whose origin has been a topic of debate for several decades. Recent work has suggested that a deep mantle plume, rooted beneath southern California, is the source of Yellowstone volcanism. Seismic anisotropy, which typically results from deformation, can be used to identify and characterize mantle flow. Here, we show that the proposed plume root location at the base of the mantle is strongly seismically anisotropic. This finding is complemented by geodynamic modeling results showing upwelling flow and high strains in the lowermost mantle beneath the Yellowstone region. Our results support the idea that the Yellowstone volcanism is caused by a plume rooted in the deepest mantle beneath southern California, connecting dynamics in the deepest mantle with phenomena at Earth’s surface.

DOI: 10.1130/G51919.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article-abstract/doi/10.1130/G51919.1/635783/Strong-seismic-anisotropy-due-to-upwelling-flow-atredirectedFrom=fulltext