41 Recent Advances in the Gulf of California Oblique Rift: Offshore and Onshore Studies // Avances Recientes en el Rift Oblicuo del Golfo de California: Estudios Marinos y Terrestres (Part III)
This session highlights recent research on the Gulf of California–Salton Trough plate boundary from ~12 Ma to today. We welcome terrestrial and marine studies involving tectonics, basin analysis, volcanology, sedimentology, and more. English or Spanish.
Friday, 24 April 2026
1:30 PM - 5:30 PM
LMH, Fiesta Terrace Salon
Seismicity Near The San Quintín Volcanic Field - Baja California, From November 2022 To Early 2025: Source Parameters, Moment Tensors, And Cluster Analysis
Paper number: 41-8
Program: Technical Sessions
Time: 3:55 PM – 4:15 PM
Authors
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Luis Yegres Presenting AuthorUniversidad Autonoma de Baja California (UABC), Ensenada, Baja California
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Oscar CastroCICESE, Ensenada, Baja California
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Usama YarbuhUniversidad Autónoma de Baja California, Ensenada, Baja California
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Carlos ReinozaCICESE , Ensenada, Baja California
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Ronald SpelzUniversidad Autónoma de Baja California, Ensenada, Baja California
Abstract
The northwestern San Quintín region, Baja California, experienced a significant phase of tectonic seismicity beginning on November 22, 2022, initiated by an Mw 6.1 mainshock. This study analyzes the subsequent seismic sequence recorded from late 2022 to early 2025 using data from RESNOM network operated by CICESE, providing a comprehensive view of the sequence evolution. Earthquake locations, local magnitudes, and selected focal mechanisms derived from first-motion polarities were determined. In addition, a subset of well-recorded events was further analyzed through full-waveform moment tensor inversion, providing enhanced constraints on source geometry and fault kinematics.
The seismicity clusters into at least two spatially distinct groups, each characterized by different fault strikes, seismic energy release, and spatio-temporal evolution. The combined focal mechanism and moment tensor solutions reveal the conjugation of fault systems with oblique kinematics, dominated by strike-slip motion, while several events exhibit a significant vertical component. These results indicate internal variability in rupture processes within the sequence and support the interpretation of an active and heterogeneous deformation regime.
The results confirm the tectonic origin of the sequence, independent of the nearby San Quintín Volcanic Field, and contribute to the seismotectonic framework of northwestern Baja California. This study provides essential constraints for seismic hazard assessment and seismic microzonation, particularly in the context of rapid population growth and ongoing urban development in the recently established municipality of San Quintín.
Geological Society of America Abstracts with Programs. Vol. 58, No. 3
doi: 10.1130/abs/2026CD-410981
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