Proceedings of the 12th International INQUA meeting on paleoseismology, active tectonic and archaeoseismology

192 1 2 T H I N T E R N AT I O N A L I N Q U A M E E T I N G O N PA L E O S E I S M O L O G Y , A C T I V E T E C T O N I C S A N D A R C H A E O S E I S M O L O G Y ( PATA ) , O C T O B E R 6 T H - 1 1 T H , 2 0 2 4 , L O S A N D E S , C H I L E PATA Days 2024 K E Y W O R D S seismogenic fault, paleoseismological trench, Colca, crustal earthquake Krzysztof Gaidzik (1) Andrzej Tyc (1) Marta Woszczycka (1) María Teresa Ramírez- Herrera (2) Carlos Benavente (3) Justyna Ciesielczuk (1) Laurence Audin (4) (1) Institute of Earth Sciences, University of Silesia in Katowice, Sosnowiec, Poland. (2) Laboratorio de Tsunamis y Paleosismología, Universidad Nacional Autónoma de México. (3) Instituto Geológico Minero y Metalúrgico (INGEMMET), Lima, Peru. (4) IRD, ISTerre, Université Grenoble Alpes, 1381 rue de la Piscine, 38610 Gieres, France. *Email: krzysztof.gaidzik@us.edu.pl, andrzej.tyc@us.edu.pl, woszczyckamarta@gmail.com, justyna.ciesielczuk@us.edu.pl / tramirez@geografia.unam.mx / cbenavente@ingemmet.gob.pe / laurence.audin@ird.fr EXPLORING THE SEISMIC HISTORY OF CRUSTAL FAULTS IN THE COLCA REGION A B S T R A C T The Colca Region in southern Peru is characterized by high seismic and volcanic activity, which results in earthquakes, volcanic eruptions, thermal waters, and mass movements. To understand these processes, history and their mutual direct and indirect relationships and influence, we advocate for a multidisciplinary methodology that integrates field tectonic, geomorphological, and geophysical survey, morphotectonic analysis, focal mechanism review of recent events, seismo-lineaments computation, hydrogeochemical and isotopic analysis of springs and geysers associated with crustal faults, palaeoseismological trenching, dating of potentially coseismic rockslides, and disrupted/ deformed sediments seen in trenches and natural outcrops, calculation of Coulomb stress-transfer between studied faults, and archaeoseismological studies of churches and pre-Hispanic archaeological sites. I N T R O D U C T I O N Southern Peru is frequently hit by large and great megathrust earthquakes related to the subduction of the Nazca Plate beneath the South American Plate (e.g., Chlieh et al., 2011). However, the Colca Region, especially its central and upstream sections experiences significantly more damage caused by shallow seismic events triggered by local, relatively short, and pronounced in the morphology seismogenic crustal faults (e.g., Antayhua et al., 2002; Benavente et al., 2015, 2017; Delgado et al., 2016; Gaidzik & Więsek, 2021; Gaidzik et al., 2022; Woszczycka et al., 2024;