The latest Chaitén updates have arrived in my inbox since yesterday, but I haven’t had a chance to check them until now. This information has not yet been published on the SERNAGEOMIN website. Alan Sullivan has already published his thoughts on the latest information, and commented here on an earlier post.

SERNAGEOMIN reports that from 25 to 28 June visual observations of the volcano have been impossible because of the bad weather. The heavy rains have produced flooding and lahars in the watercourses around the volcano, particularly the Chaitén and Amarillo rivers (there have been some news stories in the Chilean press over the past few days reporting on the new flooding of Chaitén town – I’ll catch up with these, and other relevant stories, tomorrow).

There has also been an interesting rise in seismic activity over 27 and 28 June, with up to 5 VT-type earthquakes per hour, and an average of 115 earthquakes per day. Of these, between 25 and 30 earthquakes per day exceed magnitude 2. No HB or LP type earthquakes have been detected. The VT earthquakes were located west and southwest of the volcanic caldera, at a distance of less than 10km from the volcano (in other words, they were between the volcano and Chaitén town). SERNAGEOMIN hedges its bets somewhat as to the meaning of this seismic activity:

In part, the reported seismic activity may be related to the activation of geological faults in the vicinity of the volcano. The location of the earthquakes (less than 10km from the volcano) suggests that the more major seismic activity may caused by the rupturing of rocks and the movement of fluids at depth, in the lower part of the upper system of the volcano. In any case, there has been no confirmation of a new injection of magma at depth and/or a pressurization of the upper system.

SERNAGEOMIN is maintaining volcanic red alert.

Skies have been clearer over Chaitén today and the north-facing webcam at the airfield has been giving some good views of the eruption plume. This image is from 16:16 local time today and shows the late afternoon sun gilding a low plume that is trailing away to the north-east.

For all our Chaitén coverage: Chaitén << The Volcanism Blog

Information
Global Volcanism Program: Chaitén – summary information for Chaitén (1508-41)
ONEMI, Oficina Nacional de Emergencia – Chilean government emergencies office (Spanish)
SERNAGEOMIN – Servicio Nacional de Geología y Minería (Spanish)