Abstract

The triple junction between the Cocos (CO), North American (NA), and Caribbean (CA) tectonic plates in Guatemala is a region of high seismic risk and includes many large faults and historic earthquakes. Previous analyses of the tectonic system have been overly simplified, resulting in discrepancies between geologically derived and geodetic models of fault slip rate. This study leverages available geodetic, seismic, and geologic data to develop new strain rate maps and faulting models for the region. We find that locking on the regional faults matches historic reports of large earthquakes and that multiple minor fault segments are active and accommodate strain. Moment deficit rate (MDR) calculated from strain rates using a Kostrov-type approach and an elastic fault model are gives 0.36-0.96x1019 N m/yr and 0.73-0.89 x1019 N m/yr, respectively, in comparison to an estimated moment rate from historic earthquakes of 0.21-0.37 x1019 N m/yr. Finite element modeling of the fault system shows that long-term slip rates agree better with geologic slip rate estimates when including minor faults and inelastic bulk crustal strain. These findings suggest that seismic hazard is distributed across multiple crustal faults in the region and agrees with prior studies that the forearc sliver is sutured to the North American plate.

Department(s)

Geosciences and Geological and Petroleum Engineering

Sponsor(s)

Publication funding received from the Library Subvention Fund.

Keywords and Phrases

InSAR, GNSS, faulting, seismic hazard, strain rates, North American - Caribbean Plate, Boundary, strike-slip faults, slip rates, Guatemala, tectonics

Document Type

Article - Preprint

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2026 The Authors / Funder, All rights reserved.

Publication Date

July 24, 2025

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