Advection of heat from the El Tatio geothermal system since the late Pliocene

Monday, 8 January 2018
Salon Maule (Hotel Quinamavida)
Carolina Munoz Saez1, Michael Manga2, Silvina Slagter1, Dakota Churchill2, Shaul Hurwitz3 and Martin Reich1, (1)University of Chile, Department of Geology and Andean Geothermal Center of Excellence (CEGA), Santiago, Chile, (2)University of California Berkeley, Berkeley, CA, United States, (3)USGS Western Regional Offices Menlo Park, Menlo Park, CA, United States
Abstract:
The Altiplano-Puna volcanic complex in northern Chile is characterized by extensive volcanism during the last 10 Ma. The most recent volcanic phase includes minor Holocene andesitic to dacitic eruptions and a series of late Pleistocene domes.

Geothermal systems play an important role transferring heat within volcanic arcs. El Tatio in northern Chile is one of the largest and best-studied geothermal fields in South America. Studies from the 1970s assumed that Holocene andesitic stratovolcanoes with no historical eruptions provided the heat fueling of the geothermal system.

To quantify the amount of heat discharged by the El Tatio geothermal system, we obtained geochemical new 14C ages for the geothermal deposits, we calculated the current heat discharge from field measurements of temperature and the geochemistry of the discharged fluids. 14C dating indicates an active geothermal system pre-Holocene, possible up to 20 ka. We estimate the present thermal water discharged in the order of 175 L/s. The temperature of the geothermal reservoir is >200oC, implying 160 MW of advected heat. Similar values have been found at Wairakei, New Zealand, and El Chichon, Mexico. Given that El Tatio has been active since the late Pliocene, a significant amount of heat has been advected by this hydrothermal system.

<< Previous Abstract | Next Abstract >>