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Volcanic unrest at Nevados de Chillán (Southern Andean Volcanic Zone) from January 2019 to November 2020, imaged by DInSAR

March 17, 2022

The volcanic complex of Nevados de Chillán, located in the Southern Volcanic Zone (SVZ) of the Andes, has been active for the past 640 ± 20 ka. Its volcanic activity includes dome forming eruptions, explosive events, and lava flows. The most recent eruption cycle started in January 2016. We employ DInSAR time-series from Sentinel-1 data to investigate the unrest episode from January 2019 to November 2020. Two distinct periods of unrest are recognized in the time series. The first period (from January to October 2019) coincides with explosive events, dome growth inside the active crater, and a decrease in seismic activity but does not present a significant deformation. The second period (October 2019 to November 2020) is characterized by a displacement towards the sensor's line-of-sight of 100–120 mm. The observed surface deformation is compatible with an inflation source approximately 1.5 km south-southwest of the present active vent, at 5.5 ± 0.5 km depth from the surface, and with a volume change of 0.044 ± 0.014 km3. The most likely explanation for the observed inflation of Nevados de Chillan is the intrusion of magma in a reservoir feeding the current eruption cycle.

Publication Year 2022
Title Volcanic unrest at Nevados de Chillán (Southern Andean Volcanic Zone) from January 2019 to November 2020, imaged by DInSAR
DOI 10.1016/j.jvolgeores.2022.107568
Authors Ana Astort, Gregorio Boixart, Andrés Folguera, Maurizio Battaglia
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Volcanology and Geothermal Research
Index ID 70241061
Record Source USGS Publications Warehouse
USGS Organization Volcano Science Center
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