Description

This field trip will investigate the links between the latitudinal tectonic transition from normal to flat-slab subduction and surface hazards in the Southern Central Andes, approximately at 33°S and 34°S. The main focus of this trip is to compare two complementary transects across the Andes.

​

In Chile, we will work along the Principal Cordillera near Santiago, within the normally dipping subduction segment and an area characterized by active volcanism. Field targets will include active and potentially active fault systems, hydrothermal manifestations of active volcanism, glacial and volcanic landscapes, mass movements processes and other geomorphic evidence of past and ongoing surface processes. Particular attention will be given to the relationships between active faulting, inherited structures, volcanism, and slope instability in a region where these processes interact close to a densely populated urban corridor.

​

The transect will then cross the Andes through Paso Los Libertadores - Cristo Redentor into Argentina, entering the transitional zone between the normal subduction regime to the south and the flat-slab segment to the north. Along the eastern side of the Andes, we will investigate a sequence of contrasting tectonic and geomorphic domains, extending from the Principal Cordillera through the Frontal Cordillera and Precordillera to the city of Mendoza located in the foreland. Field investigations will focus on active and potentially active faults, landslides, recent debris flows and rock falls and glacial landforms in paraglacial context, and sedimentary records, as well as geomorphic expressions of tectonic deformation. Together, these sites will allow us to explore how tectonic inheritance and changes in subduction geometry may influence surface processes and associated geohazards.

​

The field trip will be organized around a comparative framework, with participants collecting observations and data that can be integrated across the Chilean and Argentine transects. The goal is not only to document individual hazards, but to explore the processes linking deep Earth dynamics with surface responses, and to identify similarities and differences between two cross-sections and the western and eastern Andean fronts in a bivergent mountain belt. The field trip will provide opportunities for collaborative field mapping, geomorphological and structural observations, remote-sensing and drone-based data collection, and discussion of outstanding scientific questions. Data and observations collected during the trip will contribute to the development of new research ideas, collaborative projects, and potential co-authored scientific outputs, while also establishing a foundation for future comparisons with other subduction zones, as for example the Cascades arc.

​

The field trip will include collaborative office and discussion days to consolidate observations, integrate datasets, and develop shared interpretations. All participants will be encouraged to contribute to common field projects, methodological cross-training, and the development of research products. The overarching goal is to strengthen interdisciplinary collaboration while establishing a comparative framework for understanding how tectonic transitions influence volcanism, active deformation, landscape evolution, and surface hazards in subduction zones.

​​

DATES: The field trip will span March 6–13, 2027, with travel days before and after the field component. Participants will arrive in Santiago, Chile, on March 5 and depart from Mendoza, Argentina, on March 14. The itinerary will include an international border crossing through Paso Los Libertadores-Cristo Redentor, so participants must have the appropriate travel documents to complete immigration and customs procedures. Participants are required to attend a virtual pre-trip planning/onboarding meeting. 

​

FUNDING: Funding for participant travel, food, lodging, and field supplies wi available through SZNet which is supported by funding from the National Science Foundation AccelNet program under award 2301732.

​​