Magma extrusion during the Ubinas 2013–2014 eruptive crisis based on satellite thermal imaging (MIROVA) and ground-based monitoring

Abstract

After 3 years of mild gases emissions, the Ubinas volcano entered in a new eruptive phase on September 2nd, 2013. The MIROVA system (a space-based volcanic hot-spot detection system), allowed us to detect in near real time the thermal emissions associated with the eruption and provided early evidence of magma extrusion within the deep summit crater. By combining IR data with plume height, sulfur emissions, hot spring temperatures and seismic activity, we interpret the thermal output detected over Ubinas in terms of extrusion rates associated to the eruption. We suggest that the 2013-2014 eruptive crisis can be subdivided into three main phases: (i) shallow magma intrusion inside the edifice, (ii) extrusion and growing of a lava plug at the bottom of the summit crater coupled with increasing explosive activity and finally, (iii) disruption of the lava plug and gradual decline of the explosive activity. The occurrence of the 8.2 Mw Iquique (Chile) earthquake (365 km away from Ubinas) on April 1st, 2014, may have perturbed most of the analyzed parameters, suggesting a prompt interaction with the ongoing volcanic activity. In particular, the analysis of thermal and seismic datasets shows that the earthquake may have promoted the most intense thermal and explosive phase that culminated in a major explosion on April 19th, 2014. These results reveal the efficiency of space-based thermal observations in detecting the extrusion of hot magma within deep volcanic craters and in tracking its evolution. We emphasize that, in combination with other geophysical and geochemical datasets, MIROVA is an essential tool for monitoring remote volcanoes with rather difficult accessibility, like those of the Andes that reach remarkably high altitudes.

Volcanic gas emissions and degassing dynamics at Ubinas and Sabancaya volcanoes; implications for the volatile budget of the central volcanic zone

“…The current activity started with phreatic eruptions and is now characterised by vulcanian eruptions. On March 19, 2014, incandescent lava could be observed in the crater (Coppola et al, 2015). At the time of our investigation in November 2015 the eruption frequency was around one vulcanian eruption per week.…”

“…This episode of unrest, characterised by vulcanian explosions emitting juvenile material of andesitic composition, was the first crisis at Ubinas to be closely monitored by scientists (Rivera et al, 2010). In September 2013 eruptive activity resumed at Ubinas volcano (Coppola et al, 2015) and is ongoing at the time of writing. The current activity started with phreatic eruptions and is now characterised by vulcanian eruptions.…”

Detection of pre-eruptive seismic velocity variations at an andesitic volcano using ambient noise correlation on 3-component stations: Ubinas volcano, Peru, 2014

“…During the last stage, between 20 and 1 ka, the eruptive behavior has been dominantly explosive, and the summit caldera was formed in association with a large-scale Plinian eruption, between (Figure 3c; delimited by the red dashed line). Thermal anomalies were also detected by the MIROVA hot-spot detection system (Coppola et al, 2015). This activity increased significantly until the first major explosion on 13 April.…”

Thermal Remote Sensing for Global Volcano Monitoring: Experiences From the MIROVA System

“…For example, during the eruptive crisis of Ubinas in 2014, the detection of a small thermal anomaly inside the deep crater signaled the first appearance of a lava dome (confirmed only later by observations on the ground) after several days of seismic unrest. The opening of a magma path marked the beginning of an intense explosive activity that culminated few weeks later in a series of major explosions (Coppola et al, 2015). The fast detection of thermal anomalies is therefore very important to indicate the opening of the system, and coupled with other geophysical parameters often leads the rise of the alert level, as recently occurred at Sabancaya (Perù) (Reath et al, 2019b).…”

“…Similarly, during the 2014 eruption of Ubinas (Peru), the increasing VRP values were compared with the state of seismicity, as well as with other parameters (such as ash or SO 1 missions, etc. ; Coppola et al, 2015) to provide, eventually, recommendations to the civil protection authorities for the evacuation of the population.…”