Dynamics of 3-Dimensional Deformation at the Mendocino Triple Junction Across Timescales

该项目旨在测量门多西诺三重结合部的持续变形，三个主要构造板块在加利福尼亚州北部交汇处。这一地区发生的地震比美国西部任何其他地区都要大。为了了解影响其地震活动的因素，PI的团队将利用GPS和卫星雷达数据重点研究垂直位移。垂直形变速率是理解在收敛板块边界上产生地震的过程的关键。虽然精确测量垂直位移具有挑战性，但持续不断的技术进步每年都会提高精度。门多西诺三联结因其极高的地表隆起率而独一无二地适合于本研究。该团队将对变形数据进行三维建模，并将其与其他地球物理观测结果进行比较。其目标是将长期、永久性的形变与短期形变分离并量化，短期形变加载断层并潜在地驱动地震破裂。这项工作将有助于更好地理解活动构造中的长期问题，如短期形变和长期形变之间的关系，以及加州北部地壳隆起的机制。这个为期两年的项目将为一名地质学女研究生提供支持，预期结果将有助于评估和预测美国西部的地震灾害。准确测量会聚板块边缘的隆升速率，可提供有关地震和建筑永久地形的潜在过程的关键信息。测量和解释抬升速率具有挑战性，因为构造速率很慢，短期(在地震周期内)和长期变形之间的关系尚不清楚。门多西诺三重结合部是太平洋板块、胡安德富卡板块和北美板块的交汇处，为研究垂直形变提供了独特的天然实验室。在该地区，海岸抬升的地质速率是美国大陆最高的之一。在这里，PI的团队将通过集成三种类型的大地测量数据(GPS、InSAR和GRACE)来开发门多西诺三重结点的密集地震间速度场。目标是使用三维数据集来测试弹性地震间应变累积、永久非弹性变形和地球动力学地壳结构的模型。这项为期两年的项目将为一名女研究生提供支持，并通过量化断层的弹性应变载荷，从而帮助评估地震危险性。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project seeks to measure the ongoing deformation at the Mendocino Triple Junction, where three major tectonic plates meet in northern California. This region hosts larger earthquakes than any other in the western United States. To understand the factors contributing to its seismicity, the PI's team will focus on vertical displacements using GPS and satellite radar data. Vertical deformation rates are key to the understanding of the processes generating earthquakes in convergent plate boundaries. Although it is challenging to measure accurately vertical displacements, ongoing technical advances improve the accuracy each year. The Mendocino Triple Junction is uniquely suited for this study because of its extremely high surface uplift rates. The team will model in three dimensions the deformation data and compare them with other geophysical observations. The goal is to separate and quantify the long-term, permanent, deformation from the short-term deformation which loads the faults and potentially drives earthquake ruptures. This work will contribute to better understand long-standing issues in active tectonics, such as the relationship between short-term and long-term deformation, as well as the mechanisms of crustal uplift in northern California. The two-year project will provide support for a female graduate student in Geology and the expected results will help assessing and forecasting earthquake hazards in the western United States. The accurate measurement of uplift rates at convergent plate margins provide critical information on the underlying processes generating earthquakes and building permanent topography. Measuring and interpreting uplift rates is challenging, as tectonic rates are slow and the relationship between short-term (over earthquake cycles) and long-term deformations remains unclear. The Mendocino Triple Junction, where the Pacific, Juan de Fuca, and North American plates meet, provides a unique natural laboratory for studying vertical deformation. In this region, geologic rates of coastal uplift are among the highest in the continental United States. Here, the PI's team will develop a dense interseismic velocity field of the Mendocino Triple Junction by integrating three types of geodetic data (GPS, InSAR, and GRACE). The goal is to use the three-dimensional dataset to test models of elastic interseismic strain accumulation, permanent inelastic deformation, and geodynamic crustal structure. The two-year project will provide support for a female graduate student and help assessing earthquake hazards by quantifying fault elastic-strain loading, hence the fault potential to produce earthquake-generating ruptures.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.