Chaitén volcano (Chile): increased seismic activity
Friday Nov 22, 2013 08:57 AM | BY: T
Increased seismic activity has been detected under the volcano, Chilean scientists reported.
The devastating Plinian eruption of Chaitén in May 2008 forced the evacuation of the entire population of the small coastal town of Chaitén, located only a few kilometers south of the volcano. After the initial explosive phase, several lava domes have been growing slowly by extrusion of degassed, viscous magma. This phase ended in 2011 and since then, the volcano has only produced degassing.
On 20 Nov at 08:07 (local time), a volcano-tectonic magnitude 2.4 earthquake occurred at 6 km depth north-east of the volcano. It was followed by a swarm of more than 80 quakes of mostly long-period type, characteristic for movements of fluids (gasses, water, and possibly magma) inside cracks inside the volcanic edifice. They are considered potential precursors to eruptive activity. In addition, pulses of volcanic tremor and a second volcanic-tectonic quakes of magnitude 2.7 at 11:39 local time, this time at shallow 4.4 km depth were recorded.
Volcanologists from SERNAGEOMIN mentioned that at the time of publication of their report, the seismicity continued, but the official alert level of Chaitén remains green. For now, the signs of unrest are weak and it is not likely that a new eruption is immediate.
Links / Sources:
Links / Sources:
Thursday, Nov 12, 2009
Chaitén's lava dome continues its growth and can shed pyroclastic flows and produce ash eruptions at all times. The alert level remains at its highest (red). [more]
Tuesday, Mar 10, 2009
On 24 February it was reported that a partial dome collapse of Chaitén's Domo Nuevo 1 lava-dome complex a large amount of material accumulated in the basal ring depression surrounding the dome complex and throughout the Blanco River valley. Steam plumes with little ash content and explosions were noted. ... [more]
Friday, Feb 20, 2009
Chaitén volcano experienced an increase in activity over the past few weeks. Yesterday, around 11 am local time on 19 Feb., a largere section of the growing lava dome in the crater collapsed, triggering a large pyroclastic flow that came close to the already largely abandoned town of Chaitén. According to press reports, heavy ash falls occurred in the area and the evacuation of the remaining residents of the town is under way. ONEMI reports the eruption of a considerable column of ash. ... [more]
Thursday, Jan 15, 2009
It was reported that during 29 December-9 January Chaitén's lava dome continued to grow. Plumes rose to altitudes of 2.6-3.1 km. Block-and-ash flows from frequent spine collapses fell down from the edge. ... [more]
Friday, Nov 21, 2008
During 12-17November ash plumes from Chaitén continuously rose to altitudes 1.4-3.7 km and a thermal anomaly was detected on satellite photos on 12 November [more]