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WITHDRAWN Lithospheric Structure of the Hispaniola and Puerto Rico/Virgin Islands Microplates Using Teleseismic and Local Data

Description: 

WITHDRAWN The complex tectonics and high seismic activity of the Caribbean-North American plate boundary region is well documented. Hispaniola, in particular, has a history of devastating earthquakes with numerous aftershocks, but a better understanding of regional tectonics, as well as reliable estimates of seismic and tsunami hazards, await the development of a detailed 3D seismic velocity model and a comprehensive earthquake catalog with accurate locations. Moreover, the region experiences earthquakes to depths of ~200 km beneath eastern Hispaniola and the Mona Passage, the causes of which are not well understood. Various authors suggest that these earthquakes may result from the interactions between converging tectonic plates, or due to the subduction of the North American plate's slab edge beneath Puerto Rico, or from activity along a subduction transform edge propagator fault, but these hypotheses require further investigation.

To better constrain regional seismicity and advance our understanding of lithospheric structure in the region, this study leverages data recorded by local seismic networks to perform 3D seismic travel time tomography. Seismic stations have monitored the region comprehensively for the last decade, so the recorded data enable the development of a more detailed and accurate 3D model than has been possible previously. We measured ~5,609 teleseismic P-wave travel times from 189 earthquakes with magnitudes >5.5 recorded by 90 stations. Additionally, we have ~307,000 P (and S) arrivals from well-located local events (M>2.7). The model space is divided into two layers, crust and mantle, and is delimited by latitudes 15°S and 26°N and longitudes 58.75°E and 85°W. Nodes are spaced 14.5 km apart in depth and 25 km laterally in the crust and 20 km apart in depth and 40 km laterally in the mantle. The final 3D model is found with five iterations, in which raytracing is performed after each iteration until residuals change less than 5% between iterations.

Session: Characteristics and Mechanics of Fault Zone Rupture Processes, from Micro to Macro Scales [Poster Session]

Type: Poster

Date: 5/2/2024

Presentation Time: 08:00 AM (local time)

Presenting Author: Sandra Patricia

Student Presenter: Yes

Invited Presentation: 

Authors