Source Model for Sabancaya Volcano Constrained by DInSAR and GNSS Surface Deformation Observation

Gregorio Boixart,Pablo A Euillades,Luis F Cruz,Leonardo D Euillades,Rafael Miranda Cruz,Maurizio Battaglia

doi:10.3390/rs12111852

Abstract

Sabancaya is the most active volcano of the Ampato-Sabancaya Volcanic Complex (ASVC) in southern Perú and has been erupting since 2016. The analysis of ascending and descending Sentinel-1 orbits (DInSAR) and Global Navigation Satellite System (GNSS) datasets from 2014 to 2019 imaged a radially symmetric inflating area, uplifting at a rate of 35 to 50 mm/yr and centered 5 km north of Sabancaya. The DInSAR and GNSS data were modeled independently. We inverted the DInSAR data to infer the location, depth, and volume change of the deformation source. Then, we verified the DInSAR deformation model against the results from the inversion of the GNSS data. Our modelling results suggest that the imaged inflation pattern can be explained by a source 12 to 15 km deep, with a volume change rate between 26 × 106 m3/yr and 46 × 106 m3/yr, located between the Sabancaya and Hualca Hualca volcano. The observed regional inflation pattern, concentration of earthquake epicenters north of the ASVC, and inferred location of the deformation source indicate that the current eruptive activity at Sabancaya is fed by a deep regional reservoir through a lateral magmatic plumbing system.

Highlights

Sabancaya is a 5980 m-high stratovolcano located in the Central Volcanic Zone (CVZ) of the Andes, 75 km northwest of the city of Arequipa, Perú
The SAR dataset consists of 84 ascending (Path 47, Frame 1125) and 79 descending orbit (Path 25, Frames 614-646) scenes acquired by the Sentinel-1 Mission (European Space Agency, C-Band) between October 2014 and March 2019
Sub-swath 2 of the ascending orbit and sub-swath 1 of the ascending orbit cover the whole area of interest (Figure 1). They were processed using our own implementation of the DInSAR Small Baseline Subsets (SBAS) time-series approach [12], which allows a proper spatial and temporal characterization of the deformation patterns occurring within the studied area

Summary

Introduction

Sabancaya is a 5980 m-high stratovolcano located in the Central Volcanic Zone (CVZ) of the Andes, 75 km northwest of the city of Arequipa, Perú. It is the youngest and most recently active of the three volcanoes of the Ampato-Sabancaya Volcanic Complex (ASVC), which includes Hualca Hualca to the north and Ampato to the south (Figure 1). Tahneompraeliseesn[t1e0]r.uSpetiisvmeicciytycleduorfinSgabtahniscapyeraiobdegisancoinncNenotrvaetmedbmera2in0l1y6naonrdthroefmSaaibnasnocanygao, ianrgouthnrdough May 2020, when this paper was accepted It is characterized by phreatic and Vulcanian explosions associated with constant SO2 and ash emissions, accelerated lava dome growth, and thermal anomalies [10]. The observed deformation field is compatible with a deep source, 12–15 km below the surface and 5 km north of Sabancaya, that has possibly been feeding the current Sabancaya eruptions

Synthetic Aperture Radar Data

GNSS Data

26 September 2014

Modelling

Discussion

Conclusions