An e-mail brings the latest SERNAGEOMIN report (dated 30 July 2008), available here at Werner Luis’s site, on the Chaitén eruption. Seismic activity remains significant and intriguing, despite a recent slight decrease, and the high proportion of more powerful quakes is notable. Some information on the depths of these earthquakes over the last few days would be of great interest.

Special Report on Chaitén volcano, 30 July 2008

Between 1600 yesterday and 0800 today, 30.07.08, Pumalín, Santa Bárbara and Llifén stations detected 6 earthquakes per hour (96 earthquakes in 16 hours), within which one earthquake per hour was of a magnitude between 3.6M and 4.0M (16 earthquakes in 16 hours). The other earthquakes remained around 2.5M. So, with regard to the previous 24 hours, it seems that in the last 16 hours there has been a slight lowering both in the total number of earthquakes and in the number of greater magnitude.

Between 0100 and 0400 today 30.07.08, four significant earthquakes were recorded, which reached magnitudes of approximately 4.0M and were perceptible to police in the area of Chaitén. According to data from ONEMI in the region, none of the major earthquakes was perceived in Hornopirén. These major earthquakes are located, provisionally, 7.0km north-east of the volcano.

The weather at Chaitén has been clear today for the first time in some days, producing some nice images on the airfield webcam. The image below, showing a low eruption plume, was taken at 13:28 local time.

As Alan Sullivan points out there is evidence of a new vent in the west or south-west portion of the caldera.* It’s clearer in the image below, which is a detail of the view captured at 12:23 today: a small plume, just to the left of the main emission column.

* As also suggested by JC’s comment on this post of 29 July. Well spotted.

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)
Erupción del Volcán Chaitén – extensive coverage of the Chaitén eruption