Rincón de la Vieja volcano, Costa Rica: activity updates
Rincon de la Vieja volcano (Costa Rica): new explosion, evidence of fresh magma
Saturday Mar 12, 2016 09:40 AM | BY: T
Last Wednesday's eruption at Rincón de la Vieja volcano (OVSICORI-UNA)
The new ash deposit on the northern crater flank (OVSICORI-UNA)
The volcano had a new explosion from its crater lake last Wednesday 8 March. The eruption threw deposits of mud and ash onto the northern side of the crater to up to 120 m distance from the rim and generated a small plume of ash that caused light ash fall in nearby villages in up to 6 km distance to the north.
Close-up of the erupted ash: b) and c) show glassy lava from fresh magma (OVSICORI-UNA)
The activity at the volcano had started to increase already in 2015. Volcanologists have found evidence of several similar explosions that occurred in the past months, but the most recent one on Wednesday seems to have been significantly larger (although still small in itself).
The most interesting news, however, comes from the analysis of the ejected ash. OVSICORI-UNA staff found that besides fragmented older rocks and sulfur, about 3-10 % of the ejected ash particles are glassy shards from juvenile (i.e. new) magma.
This means that the explosions were not entirely driven by steam only (so-called phreatic explosions), but involved a component of fresh magma that seems to have recently risen to shallow depths near the surface and was contributing to the energy of the explosion (phreatomagmatic activity). This could (but not necessarily must) signify that more eruptive activity, potentially stronger, is going to occur at the volcano in the near to medium-term future.
Links / Sources:
Links / Sources:
- OVSICORI-UNA (facebook)
Sunday, Sep 21, 2014
The volcano increased its activity. Since 17 Sep, phreatic explosions have regularly occurred from the main crater which contains an acid lake. Although none was observed directly, at least 6 explosions could be identified by seismic signals. An aerial survey yesterday showed no fresh deposits, which suggests that the eruptions were rather small and did not eject material beyond the lake. ... [more]
Wednesday, Mar 06, 2013
OVSICORI-UNA received reports at 05:30 on 26 February of pulsing white plumes rising from Rincon de la Vieja's active crater about every four minutes. ... [more]
Rincón de la Vieja volcano (Costa Rica) activity update: increased degassing and temperature at acid crater lake
Saturday, Oct 06, 2012
The volcano has a very active hot lake whose degassing activity and temperature (48° C) increased after the magnitude 7.6 earthquake on 5 Sep. It has milky gray color due to mixing of sediments. ... [more]
Thursday, Apr 12, 2012
Over the past weeks, the National Park of Rincón de la Vieja has been observing an increase in volcanic activity, and a small phreatic eruption occurred from the main crater on 11 April. [more]
Thursday, Mar 01, 2012
New phreatic explosions were recorded at Rincón de la Vieja volcano in northern Costa Rica. ... [more]