The Cordón Caulle volcano is part of the Puyehue-Cordón Caulle Volcanic Complex along the Andes mountain range in southern Chile. Helge Gonnermann and his research group are part of a collaboration supported by a Frontier Research in Earth Sciences (FRES) grant from the National Science Foundation, to study how the volcano is changing and what risks might arise in the region as a result.
“The scientific objectives include understanding why and how the laccolith formed during the 2011/2012 eruption of Cordón Caulle, the state of the laccolith, risks associated with the steep topography, faulting, and landslides, and the thermal evolution of the laccolith,” says Gonnermann.
In January, EEPS PhD candidate Jong Gil Park joined FRES colleagues from University of Nevada at Reno, Cornell University, University of Oregon, , Universidad de Chile, the Servicio Nacional de Geología y Minería, the Universidad Austral de Chile, and the Universidad de Concepción, on Cordón Caulle volcano to gather a wide range of data (https://magazine.rice.edu/winter-2023/hot-science), including the retrieval of data from previously installed instruments, as well as the deployment of new instruments that will collect additional data.
According to Jong Gil, the 2011 Cordón-Caulle eruption was one of the largest of our century, both explosively - sending ash and pumice high into the air- and effusively, pouring viscous lavas from flanking vents simultaneously. Magma also intruded just below the surface, forming a laccolith that is changing. During the eruption, the laccolith elevated the landscape more than 500 feet. At present it is unclear whether there is ground subsidence at the laccolith; however, large parts of Cordón Calle have been uplifting about one inch per month, likely due to magma migration at depth.
During the eruption, some of the lava flowed down a narrow valley, covering an existing stream. Over time, hot water has been observed at the front of the lava flow. With abundant rain or snow in this part of Chile during the winter months, a vigorous hydrothermal system has established itself. Near the laccolith, this water flows into the surface fractures, warms up, and resurfaces along the flank of the laccolith at temperatures as high as 37oC (~100 degrees Fahrenheit).
Water temperature is one of several parameters being monitored as a manifestation of heat transfer from the interior of the laccolith. “These measurements will help us [indirectly] understand what's going on at depth since we can’t directly see below to the surface,” says Jong Gil.
Jong Gil worked with Chilean scientist Pablo Becerra Sotelo from Universidad de Concepción to deploy an instrument called an "Aquatroll", which measures water temperature, pressure and electrical conductivity in the stream that drains the area of the laccolith and adjacent lava flow. In addition, they installed a time-lapse camera to capture the variations in stream flow over the next year.
“Our goal is to develop a model that explains the variation in water temperature as it is affected by precipitation and modulated by heat flow from the laccolith and lava flow. This will allow us to get a better understanding of the thermal state of the laccolith and its explosive potential, should there be a landslide or large earthquake.”
Jong Gil may have deployed the device, but Rice undergraduate Malcolm Widger from the EEPS Explorer program may retrieve the data and assist with the other 2025 season field activities. Over the course of two weeks next January, 18 people will work on various tasks, including tephra sampling and data collection. The main thrust of Jong Gil's involvement involves modeling the eruption itself and working with data collected by Thomas Giachetti, a faculty member at the University of Oregon and former postdoc at Rice University, as well as Philipp Ruprecht from the University of Nevada, Reno. Separately, Jong Gil and Malcom are planning to analyze the hydrothermal data collected thus far.
“While I may not be able to go back, this research is particularly interesting to me, as it overlapped with both my Master’s studies in hydrogeology and my current research in volcanology, offering a unique intersection between these fields,” Jong Gil concludes.
See below for additional articles about the project from FRES collaborators at the University of Nevada, Reno and Cornell University:
https://www.unr.edu/nevada-today/news/2024/fres-grant-chilean-volcano
https://news.cornell.edu/stories/2024/10/geologists-visit-study-active-chilean-volcano