Characterizing infrasound and seismic data at Reventador volcano to improve hazards monitoring and risk mitigation

Abstract:

Between the provinces of Napo and Sucumbíos 100 km east of Quito lies El Reventador volcano. This volcano is one of the most active volcanoes in the Ecuadorian arc, and represents a major source of hazard, as it is very close to populated areas in the country, as well as to major infrastructure like hydroelectric power plants, roads, and oil pipelines. Currently, volcanologists and geophysicists use infrasound data along with other geophysical measurements like seismicity, deformation, gravity, and thermal cameras to monitor volcanic activity and infer eruption dynamics.

In this project, we study the degassing mechanisms at El Reventador volcano using infrasound arrays. El Reventador is an excellent target due to its intense and quasicontinuous infrasound activity. The data come from the infrasound array AZU, which includes three infraBSU microphones connected to a DATA-CUBE3 located 4 km from the summit. Due to the proximity of the sensors to the source, the signals recorded are linear acoustic waves with a minimum of attenuation. Additionally, a 120 s Trillium compact seismometer was collocated with the array during the study period. We extract relevant information about the dynamics of eruptions at this volcano by studying phases of both volcanic quiescence and degassing at El Reventador over long periods of time. Using data from May to June of 2015, we (1) characterize the infrasound signals associated with known eruptive events, (2) use these basic parameters to search for new events in the data, and (3) compare the observed events to the seismic signals. These results may be used to show possible patterns in the data that can precede paroxysmal and lava extrusion phases in El Reventador volcano.