中科大地球与行星物理学术报告通知（202602期）-German A. Prieto

报告人简介：

Dr. German Prieto is an Associate Professor at the Departamento de Geociencias, Facultad de Ciencias in the Universidad Nacional de Colombia. His research focuses on understanding the diversity of earthquakes and the associated ground motions expected on the surface of the Earth. Dr. Prieto received his PhD from Scripps Institution of Oceanography at UC San Diego working with Peter Shearer and Frank Vernon on scaling properties of earthquakes using state-of-the-art signal processing on some of the largest datasets at the time. He was a Thompson Postdoctoral Fellow at Stanford University working on seismic tomography and ground motion predictions using the ambient seismic field. Prior to his appointment at Universidad Nacional, German was a faculty member at MIT and before that faculty at Universidad de los Andes. He has also been a Visiting professor at IPGP in 2012 and at MIT (2017-2018), and more recently at Tsinghua University (2026).

Dr. Prieto’s main interest is to use seismic records to understand the earthquake source, the interior of the Earth and how both affect the ground motions that we feel on the Earth’s surface. Seismological observations are affected by the internal structure of the Earth, for example amplification of seismic waves in sedimentary basins. The nature of the earthquake source has also a significant impact on ground motions, and he is interested in a better understanding of earthquake ruptures, i.e., are large earthquakes different from the more common small ones?

报告内容摘要：

The initiation of subduction zones is a poorly understood but core plate tectonic process. One unknown is how and under what conditions previously contiguous plates break. Here we present a comprehensive assessment of the Northern Panama Subduction Zone (NPSZ) where the Caribbean Plate is subducting to the SSW beneath Panama. Because the Panama arc was built onto the Caribbean Plate, the existence of the NPSZ means that the Caribbean Plate must have broken. The significant crustal thickness (~20 km) and age (>90 Ma) of the Caribbean Plate make the NPSZ the closest analog to passive margin failure known. We use evidence from the 25-May-2023 Mw 6.3 megathrust earthquake northeast of Panama included in a newly refined earthquake catalog to identify the geometry of the downgoing plate. We combine these with plate reconstructions to study the initiation of the NPSZ, its subsequent evolution, and its tectonic implications.