Chillán volcano news & activity updates:
Nevados de Chillán volcano (Chile): new ash eruptions
Montag Mai 09, 2016 21:52 | VON: T
Eruption of Nevados de Chillan on 9 May morning (SERNAGEOMIN)Two new phases of ash explosions occurred at the volcano this morning. The first and strongest occurred at 13:03 local time, generating a dense ash plume that rose 1700 m above the crater, followed by a weaker series of ash emissions at 14:40.
The eruption plumes caused moderate ash falls in areas up to a few km downwind (north) of the crater as well as small mud flows on its upper slopes. The latter were the result of rapid interaction of hot tephra (the erupted fragmented material) with snow.
The new activity, sign of the volcano's ongoing phase of unrest, had been preceded by increasingly frequent gas and steam puffs since around yesterday evening; some of them possibly contained light ash ash well.
According to SERNAGEOMIN, the seismic activity of the volcano has been at fluctuating, but generally low energy levels during the recent weeks. Out of 614 seismic events detected during 16-30 April, more than 90% were related to internal fluid movements, in turn indicative of interaction of the volcano's (deeper) magmatic with the shallow hydrothermal system.
During today's eruptions, some of these fluids (gasses and over-pressurized water) found their way to the surface again, releasing some of the internal pressure and establishing a new (temporary) balance. A pulse of tremor accompanied the explosions (rapidly escaping gasses and rock fragments), followed by a decrease in seismic activity afterwards.
This process of intermittent phreatic activity could go on in a similar way for a long time, until it fades or escalates into a phase of more vigorous activity (e.g. if more magma rises to shallower depths), something that is impossible to predict at the moment.
The alert level of the volcano remains unchanged at "yellow", with an access restriction of 2 km radius around the crater.
Links / Quelle:
Links / Quelle:
- Nevados de Chillán (SERNAGEOMIN)
Mittwoch, Apr 20, 2016
New ash emissions occurred yesterday morning, generating a small plume that rose approx. 500 m. According to Sernageomin, this activity is not caused directly by fresh magma, but related to disturbances of the shallow hydrothermal system which interacts with an underlying, probably only small body of magma. ... [mehr]
Donnerstag, Mär 31, 2016
Intermittent ash emissions re-appeared at the volcano during the past days. ... [mehr]
Freitag, Mär 04, 2016
A small eruption occurred at the volcano again yesterday, the first activity since the mild explosive activity on 7 February. Starting around noon, the volcano began to emit a steam plume of variable intensity, sometimes mixed with ash. The activity took place at one of the new craters that had formed in early February. ... [mehr]
Montag, Feb 01, 2016
A series of new explosions with small to moderate ash emissions occurred at the volcano during the end of last week. This activity formed a second new crater, approx. 25x30 m wide and located 50 m beneath the northeast flank of Arrau crater, as SERNAGEOMIN staff observed on an overflight on 30 January. ... [mehr]
Mittwoch, Jan 13, 2016
A short pulse of ash emissions occurred in the evening of 8 Jan 2016 around 18:49 local time. ... [mehr]