Where Have All the Earthquakes Gone?

假玄武玻璃（摩擦熔体）是地震滑动的明确记录，它们在地质记录中的识别为了解地震周期期间的变形和物理条件提供了机会。在阿拉斯加的科迪亚克群岛，PI最近发现了迄今为止在增生棱柱体中最厚、体积最大的假玄武玻璃。虽然这项工作已经确定了这种独特岩性的性质和一般分布，但它也提出了许多问题，这些问题只能通过仔细记录科迪亚克假玄武质的分布，结构和形式来回答，比例范围从1：500到1：5，正如本奖项所做的那样。这种围绕海崖、海岬和潮汐暴露的测绘不仅将记录横切关系，而且将提供关于厚度、体积和几何形状的定量信息。将在科迪亚克群岛和加州其他地方的假玄武玻璃和流化岩的远景地点进行辅助实地调查。样品的分析研究将包括使用光学显微镜、电子显微镜、X射线衍射、X射线荧光和流体包裹体显微镜仔细记录纹理、密度、孔隙度、矿物学和化学，以及电阻率测量。更广泛的影响是，该研究对地震灾害有影响，这项研究涉及两名女科学家，这项研究对MARGINS社区很重要。

Pseudotachylytes (frictional melts) are an unequivocal record of seismic slip and their identification in the geologic record provides opportunities to understand deformation and physical conditions during the seismic cycle. In the Kodiak Islands of Alaska, the PI has recently discovered the thickest and most voluminous example of pseudotachylyte in an accretionary prism to date. Although this work has identified the nature and general distribution of this unique lithology, it also has raised many questions that can only be answered by careful documentation of the distribution, structure, and form of the Kodiak pseudotachylytes at scales ranging from 1:500 to 1:5, as will be done under this award. Such mapping around the seacliffs, headlands, and tidal exposures will not only document the cross-cutting relationships but provide quantitative information on thicknesses, volumes, and geometries. Ancillary field investigations will be conducted at prospective localities for pseudotachylytes and fluidized rocks elsewhere in the Kodiak Islands and in California. Analytical studies of samples will include careful documentation of texture, density, porosity, mineralogy, and chemistry, using optical microscopy, electron microscopy, X-ray diffraction, X-ray fluorescence, and fluid inclusion microscopes, plus resistivity measurements.The broader impacts are that the study has implications for earthquake hazards, that the study involves two female scientists and that the study will be important for the MARGINS community.