7) Beatriz Cosenza
Beatriz Cosenza, Professor at the University of San Carlos (Guatemala City)
Beatriz Cosenza, Professor at the University of San Carlos (Guatemala City)
Monday October 30th; 3 PM
Monday October 30th; 3 PM
Host: Jeffrey Johnson
Host: Jeffrey Johnson
Title: Regional surface deformation in northern Central America: looking down with our eyes in the sky
Title: Regional surface deformation in northern Central America: looking down with our eyes in the sky
Abstract: Tectonic deformation in northern Central America results from the interaction between the Cocos, Caribbean, and North America plates. This deformation is mostly accommodated by the sub-parallel Motagua and Polochic left-lateral faults, north-south-trending grabens south of the Motagua Fault, the Middle America subduction zone, and right-lateral faults along the Middle America volcanic arc. Large earthquakes associated with these faults include the destructive 1976 Mw 7.5 earthquake along the Motagua fault and the 2012 Mw 7.5 Champerico subduction thrust earthquake.
Abstract: Tectonic deformation in northern Central America results from the interaction between the Cocos, Caribbean, and North America plates. This deformation is mostly accommodated by the sub-parallel Motagua and Polochic left-lateral faults, north-south-trending grabens south of the Motagua Fault, the Middle America subduction zone, and right-lateral faults along the Middle America volcanic arc. Large earthquakes associated with these faults include the destructive 1976 Mw 7.5 earthquake along the Motagua fault and the 2012 Mw 7.5 Champerico subduction thrust earthquake.
GNSS measurements in northern Central America in the late nineties with broad goals of better understanding plate motions and seismic hazards in this complexly deforming region. The resulting elastic-kinematic block models for the region based on GNSS data highlight the North America and Caribbean plates' relative motion, accommodated mainly on the Motagua fault as well as on the Polochic fault. They also evidence significant internal east-west extension of the Caribbean plate between Honduras and western Guatemala, and show right-lateral slip across the Mid-America arc, with a clear velocity contrast across the El Salvador fault zone.
GNSS measurements in northern Central America in the late nineties with broad goals of better understanding plate motions and seismic hazards in this complexly deforming region. The resulting elastic-kinematic block models for the region based on GNSS data highlight the North America and Caribbean plates' relative motion, accommodated mainly on the Motagua fault as well as on the Polochic fault. They also evidence significant internal east-west extension of the Caribbean plate between Honduras and western Guatemala, and show right-lateral slip across the Mid-America arc, with a clear velocity contrast across the El Salvador fault zone.
The next logical step was to turn to interferometry of SAR images (InSAR) to exploit its greater spatial coverage. We show the potential of permanent scatterers and distributed scatterers (PSDS) InSAR techniques applied to a Sentinel-1 (S1) archive, to retrieve current deformation at large scale in this complex tectonic context for which we have obtained the first large scale InSAR-based velocity field for this region.
The next logical step was to turn to interferometry of SAR images (InSAR) to exploit its greater spatial coverage. We show the potential of permanent scatterers and distributed scatterers (PSDS) InSAR techniques applied to a Sentinel-1 (S1) archive, to retrieve current deformation at large scale in this complex tectonic context for which we have obtained the first large scale InSAR-based velocity field for this region.
Our results show a good first order agreement with GNSS data and with the most recent GNSS-based models for the region, reproducing the same main features, with the potential to obtain greater detail on the slip partitioning on the Motagua-Polochic fault system and also on the grabens, and the faults along the volcanic arc. The unprecedented high spatial density of our InSAR results allows to reveal creep ocurring along the Motagua fault. Also, due to their sensitivity to vertical motion, our InSAR measurements seem promising to make more refined estimates of lateral coupling variations along the subduction interface.
Our results show a good first order agreement with GNSS data and with the most recent GNSS-based models for the region, reproducing the same main features, with the potential to obtain greater detail on the slip partitioning on the Motagua-Polochic fault system and also on the grabens, and the faults along the volcanic arc. The unprecedented high spatial density of our InSAR results allows to reveal creep ocurring along the Motagua fault. Also, due to their sensitivity to vertical motion, our InSAR measurements seem promising to make more refined estimates of lateral coupling variations along the subduction interface.
Bio: Beatriz Cosenza is a professor of geophysics at University of San Carlos of Guatemala in the School of Physical Sciences and Mathematics. Her interests include the use of geodesy to study crustal deformation associated with different geological processes in Guatemala, geophysical methods for subsurface exploration and science popularization. She is also a primary organizer of the Cities on Volcanoes 12 conference in Antigua Guatemala in February 2024.
Bio: Beatriz Cosenza is a professor of geophysics at University of San Carlos of Guatemala in the School of Physical Sciences and Mathematics. Her interests include the use of geodesy to study crustal deformation associated with different geological processes in Guatemala, geophysical methods for subsurface exploration and science popularization. She is also a primary organizer of the Cities on Volcanoes 12 conference in Antigua Guatemala in February 2024.
Journal Article(s):
Journal Article(s):
Cosenza-Muralles_etal_GJI_2022a.pdfCosenza-Muralles_etal_GJI_2022b.pdf