Department or Program

Earth and Climate Sciences

Abstract

Fault zones are found all across the world, and to avoid inhabiting them would be impossible. The Andean Precordillera in western Argentina is one such seismically active region. It has experienced several devastating earthquakes over the past two centuries, including the Mw 7.0 1861 Mendoza earthquake, the Mw 7.4 1944 San Juan earthquake, the Mw 7.5 1977 double Caucete earthquakes and the most recent Mw 6.4 2021 earthquake once again in San Juan Mw 7.0 1861 Mendoza earthquake, the Mw 7.4 1944 San Juan earthquake, the Mw 7.5 1977 double Caucete earthquakes and the most recent Mw 6.4 2021 earthquake once again in San Juan (Kadinsky-Cade et al., 1985; Alvarado & Beck, 2006; Meigs & Nabelek, 2010; Ammirati et al., 2022). In order to mitigate earthquake risk, we investigated the east-dipping, northwest-southeast striking Marquesado Fault located approximately 12 km west from San Juan’s city center. This location falls within a ~30 km gap in paleoseismic data which provides information on earthquake history and co-seismic ruptures. Due to the fault’s remote location, we hand-dug a 6 m long and 2-2.5 m deep trench along a 400 m long west facing scarp. The location of the trench was selected along an abandoned river valley, and it revealed the Miocene basement Loma de las Tapias Formation folded and wrapped on the Quaternary alluvium along the fault. Here, we present the results of this work which bears significant importance to the seismic hazard assessment of San Juan and neighboring cities.

Level of Access

Restricted: Embargoed [Bates Community After Expiration]

First Advisor

Arora, Shreya

Date of Graduation

5-2024

Degree Name

Bachelor of Science

Number of Pages

24

Components of Thesis

1 word file (too large to export to pdf this time)

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Embargoed

Available to Bates Community via local IP address or Bates login on Thursday, May 01, 2025.

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