Paleoseismology of a Major Crustal Seismogenic Source Near Mexico City: The Southern Border of the Acambay Graben

0574021 - ÚSMH 2024 RIV US eng J - Článek v odborném periodiku
Leon-Loya, R. - Lacan, P. - Ortuno, M. - Zuniga, R.F. - Štěpančíková, Petra - Stemberk, Jakub - Hernandez Flores, A.P. - Carrera Hernandez, J.J. - Sunye-Puchol, I. - Aguirre-Diaz, G. - Audin, L.
Paleoseismology of a Major Crustal Seismogenic Source Near Mexico City: The Southern Border of the Acambay Graben.
Tectonics. Roč. 42, č. 6 (2023), č. článku e2022TC007610. ISSN 0278-7407. E-ISSN 1944-9194
Grant CEP: GA ČR GAP210/12/0573
Institucionální podpora: RVO:67985891
Klíčová slova: Paleoseismology * Trans-Mexican Volcanic Belt * Acambay Graben * Crustal prehistoric earthquakes * Multi-segment ruptures * Ground-motion hazard
Obor OECD: Geology
Impakt faktor: 4.2, rok: 2022
Způsob publikování: Open access
https://doi.org/10.1029/2022TC007610

The Trans-Mexican Volcanic Belt is an active continental volcanic arc related to subduction along the Middle America trench. It is characterized by intra-arc extension resulting into several major arc-parallel active fault systems and tectonic basins. The Acambay graben, one of the largest of these basins, is located near Mexico City, in the central part of this province. In 1912, a M 6.9 earthquake ruptured the surface along the northern border of the graben together with at least two other faults. In this paper, we analyze the paleoseismic history of the southern border of the Acambay Graben, with new observations made in one natural outcrop and four paleoseismological trenches excavated across branches of the Venta de Bravo Fault at the site where it overlaps with the Pastores Fault. We present evidence of at least two paleo-earthquakes that occurred between 12,190 ± 175 and 5,822 ± 87 cal year BP and between 647 ± 77 and 250 cal year BP. On one of these branches, we estimate a minimum slip-rate value between 0.1 and 0.23 mm/year for the last 12 ka and a mean recurrence interval of 8.5 ± 3 ka. By considering several likely rupture lengths along the Venta de Bravo and Pastores faults, we calculated a maximum possible magnitude of Mw 7.01 ± 0.27. Finally, by correlating events recorded along different faults within the Acambay Graben, we discuss several possible rupture coalescent scenarios and related consequences for Mexico City.
Trvalý link: https://hdl.handle.net/11104/0347762