Volcanic Activity Report (RAV) Bio Bio region
Nevados de Chillan volcanic complex
The level of activity of the volcanic complex is at:
LEVEL YELLOW: changes in the behavior of volcanic activity -Time For a probable eruption weeks / months.
Based on the analysis of information obtained from monitoring equipment and surveillance of the volcanic complex, the Servicio Nacional de Geologia y Mineria (SERNAGEOMIN) -Observatorio Volcanológico Los Andes del Sur (OVDAS) announces:
It was recorded five hundred sixty-nine (579) seismic events, sixty-five of which (65) were associated with rock fracturing processes, called volcano-tectonic earthquakes (VT) with a local maximum amplitude (ML) of M 2.7. On the other hand, five hundred and ten (510) earthquakes associated with fluid dynamics within the volcanic edifice, called long-period events (LP) with a lower maximum local magnitude (ML) of M 2.1 to reduced travel (DRC) to 30cm2. were recorded
In addition, four (4) pulses of tremor (TR) discreet, also associated with the fluid dynamics inside the volcano, with a reduced displacement of less than 2.0cm2 were recorded.
The images obtained through the network of cameras installed in the area, showed surface activity mainly characterized by the emission of a small white plume associated with the steam which has reached a maximum height of 300 m above the crater.
Based on the analysis of data provided by two (2) electronic inclinometers and five (5) GNSS stations that monitor the deformation of the volcanic complex, no changes due to the internal activity of the volcano were evident during this period .
The images published by the OMI Group (Monitoring Instrument – Group Sulfur Dioxide -http: //so2.gsfc.nasa.gov/) and NESDIS (National Environmental Satellite, Data, and Information – http: // sateps anone.nesdis. noaa.gov) does not report any anomaly in the emissions of sulfur dioxide (SO2) into the atmosphere in the area of the volcanic complex.
Thermal radiation released by the MODVOLC (Moderate Resolution Imaging Spectroradiometer – http://modis.higp.hawaii.edu/ MODIS) and Mirova (Middle InfraRed Observation of volcanic activity) on its website (http: // www. mirovaweb.it/), surveillance systems that indicate significant changes in surface temperature, heat alerts have reported no abnormalities in the zone associated with volcanic complex.
Monitoring of the parameters during the last two weeks has shown, usually a tendency to a balance between the surface of magmatic hydrothermal system and the underlying magmatic system. However, in recent days, the activity related to seismicity of fluids increased without affecting the superficial system, suggesting a possible slow rise of new magmatic masses to the surface or a process of destabilization by thermodynamic changes inside.
This implies the possibility of generate new phreatic explosions and / or phreatomagmatic eruptions from currently active craters.
Therefore, the volcanic alert remains at yellow level considered high risk area in the present state, including the area within 2 km from the active craters. Therefore, it is recommended to restrict access to this area.
March 07, 2016. Nevados De Chillan, Chili :
Source : Sernageomin.