Sedimentary and microfossil imprint from historical earthquakes and tsunamis, Jalisco coast, Mexican subduction
Castillo-Aja, R.; Ramírez-Herrera, M.-T.; Machain-Castillo, M.L.; Goguitchaichvili, A.; Cejudo, R. (2019). Sedimentary and microfossil imprint from historical earthquakes and tsunamis, Jalisco coast, Mexican subduction. Mar. Geol. 407: 32-43. https://dx.doi.org/10.1016/j.margeo.2018.10.004
In: Marine Geology. Elsevier: Amsterdam. ISSN 0025-3227; e-ISSN 1872-6151, more
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| Keyword |
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| Author keywords |
Rivera plate; Seismic history; Tsunami deposit; Microfossils; Grain size; Western Mexican Pacific coast |
| Authors | | Top |
- Castillo-Aja, R.
- Ramírez-Herrera, M.-T.
- Machain-Castillo, M.L.
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- Goguitchaichvili, A.
- Cejudo, R.
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| Abstract |
Tsunamis are high energy events capable of leaving their imprint in the geological record. The western Mexican Pacific coast, located in the Mexican Subduction Zone, is prone to large earthquakes (M ≥ 8.0) where tsunami hazard has been underrated. The geologic archive obtained in a sheltered coastal lagoon was analyzed applying a multi-proxy approach to reveal the occurrence of historical earthquakes in the Jalisco coast. Foraminifera and Ostracoda aid identifying earthquake and tsunami geologic evidence in this section of the Mexican Pacific coast, where tropical conditions prevail. We present the evidence of changes in stratigraphy, grain size, biostratigraphy supported by archaeomagnetic dating. They were complemented with published 210Pb dating, magnetic properties, and historical data. We identified three events: the tsunami deposit left by the June 3rd, 1932 tsunami, produced by the largest earthquake (M = 8.2) recorded in instrumental history in México and the coseismic deformation resulting from the 1932 event, also a probable tsunami deposit likely produced by an historical earthquake in 1900, and the coseismic deformation associated to this event, and the coseismic deformation resulting produced by the 1563 earthquake. The site geomorphology, with a marginal lagoon closed by a little barrier 7 m ± 1 m above sea level, precludes tropical storms as responsible for marine incursions. This work contributes to strengthening the earthquake and associated tsunamis chronology, aiming to improve coastal hazard assessment for the area. |
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