TY - JOUR
T1 - The Mechanisms of Tsunami Amplification and the Earthquake Source of the 2021 M 7 Acapulco, Mexico, Earthquake
AU - Melgar, Diego
AU - Ruiz-Angulo, Angel
AU - Crowell, Brendan W.
AU - Fielding, Eric J.
AU - Solano-Hernandez, Ericka A.
N1 - Funding Information: This research was partially funded by National Aeronautics and Space Administration (NASA) Grant Numbers 80NSSC19K0360 and 80NSSC19K1104. Part of this research was sponsored by the NASA Earth Surface and Interior focus area and performed at the Jet Propulsion Laboratory, California Institute of Technology under NASA Contract Number 80NM0018D0004. The authors would like to thank Zack Spica and Mathieu Perton for their help with extracting the velocity profile from the 3D model and Xyoli Pérez-Campos for discussions. The authors are also indebted to Randy LeVeque and Lloyce Adams for helpful conversations regarding GeoClaw setup. The authors also thank Victor Hugo Espíndola, Ivan Rodriguez, Leonardo Guzmán, Citlali Pérez, and Arturo Iglesias for their assistance with data access. This work contains modified Copernicus data from the Sentinel-1A and Sentinel-1B satellites processed by the European Space Agency (ESA) and Jet Propulsion Laboratory (JPL). Servicio Sismológico Nacional (SSN) data products station maintenance, data acquisition, and distribution are thanks to its personnel. The authors extend our gratitude as well to the Instituto de Ingeniería at Universidad Nacional Autónoma de México (UNAM) for access to the strong motion data and to the Servicio Mareográfico Nacional for access to the ACAP tide gauge. Angel Ruiz-Angulo would like to dedicate this work to the memory of Rosaura Ney Cruz (la Chata), former resident of Acapulco, who shared stories about the 1962 tsunami. Funding Information: This research was partially funded by National Aeronautics and Space Administration (NASA) Grant Numbers 80NSSC19K0360 and 80NSSC19K1104. Part of this research was sponsored by the NASA Earth Surface and Interior focus area and performed at the Jet Propulsion Laboratory, California Institute of Technology under NASA Contract Number 80NM0018D0004. The authors would like to thank Zack Spica and Mathieu Perton for their help with extracting the velocity profile from the 3D model and Xyoli Pérez-Campos for dis-cussions. The authors are also indebted to Randy LeVeque and Lloyce Adams for helpful conversations regarding GeoClaw setup. The authors also thank Victor Hugo Espíndola, Ivan Rodriguez, Leonardo Guzmán, Citlali Pérez, and Arturo Iglesias for their assistance with data access. This work contains modified Copernicus data from the Sentinel-1A and Sentinel-1B satellites processed by the European Space Agency (ESA) and Jet Propulsion Laboratory (JPL). Servicio Sismológico Nacional (SSN) data products station maintenance, data acquisition, and distribution are thanks to its personnel. The authors extend our gratitude as well to the Instituto de Ingeniería at Universidad Nacional Autónoma de México (UNAM) for access to the strong motion data and to the Servicio Mareográfico Nacional for access to the ACAP tide gauge. Angel Ruiz-Angulo would like to dedicate this work to the memory of Rosaura Ney Cruz (la Chata), former resident of Acapulco, who shared stories about the 1962 tsunami. Publisher Copyright: © Seismological Society of America.
PY - 2022/9/27
Y1 - 2022/9/27
N2 - We present a slip model for the 2021 M 7 Acapulco, Mexico, earthquake produced by inversion of strong motion, Global Navigation Satellite Systems, tide gauge, and Interferometric Synthetic Aperture Radar data. The earthquake occurs within the Guerrero gap, identified as a region of concern for its seismogenic potential and paucity of large events. We find that rupture was compact, constrained to depths between 10 and 20 km, and consistent of two main slip patches. The slip model leaves a broad swath of the megathrust unbroken, and, whether the event signals a reactivation of large earthquakes in the region remains unknown. We find that tide gauge recordings inside Acapulco Bay for the M 7 1962 earthquake and the 2021 event are strikingly similar, thus we interpret this as weak evidence that 2021 is a repeat of 1962. We also produce a high-resolution hydrodynamic model of the resulting tsunami using the slip model as initial condition and place special emphasis in understanding the long duration (∼17 hr) of waves inside the bay. We find that simple bay resonance alone does not account for the features of the event. Rather it is a complex interaction with shelf modes and edge waves that continuously re-excite the bay resonance that leads to the protracted tsunami disturbances. Furthermore, we find that significant currents in excess of 1 m/s occur in localized portions of the bay even when wave amplitudes remain small.
AB - We present a slip model for the 2021 M 7 Acapulco, Mexico, earthquake produced by inversion of strong motion, Global Navigation Satellite Systems, tide gauge, and Interferometric Synthetic Aperture Radar data. The earthquake occurs within the Guerrero gap, identified as a region of concern for its seismogenic potential and paucity of large events. We find that rupture was compact, constrained to depths between 10 and 20 km, and consistent of two main slip patches. The slip model leaves a broad swath of the megathrust unbroken, and, whether the event signals a reactivation of large earthquakes in the region remains unknown. We find that tide gauge recordings inside Acapulco Bay for the M 7 1962 earthquake and the 2021 event are strikingly similar, thus we interpret this as weak evidence that 2021 is a repeat of 1962. We also produce a high-resolution hydrodynamic model of the resulting tsunami using the slip model as initial condition and place special emphasis in understanding the long duration (∼17 hr) of waves inside the bay. We find that simple bay resonance alone does not account for the features of the event. Rather it is a complex interaction with shelf modes and edge waves that continuously re-excite the bay resonance that leads to the protracted tsunami disturbances. Furthermore, we find that significant currents in excess of 1 m/s occur in localized portions of the bay even when wave amplitudes remain small.
UR - https://www.scopus.com/pages/publications/85139500015
U2 - 10.1785/0120220098
DO - 10.1785/0120220098
M3 - Article
SN - 0037-1106
VL - 112
SP - 2902
EP - 2914
JO - Bulletin of the Seismological Society of America
JF - Bulletin of the Seismological Society of America
IS - 6
ER -