The most recent SERNAGEOMIN report on Chaitén has been issued (but not published on the internet at the SERNAGEOMIN site or elsewhere; the most recent report publicly available remains that of 26 June). Translation as follows:

ERUPTION OF CHAITÉN VOLCANO
THIRTY-THIRD TECHNICAL REPORT, 2 JULY 2008
SERNAGEOMIN

1. VISUAL OBSERVATIONS
Today, weather conditions have prevented  visual observation from Queilen.

2. SEISMIC ACTIVITY
The telemetric stations PUMA and STAB continue to register seismic activity similar to the preceding days, with an average of 130 VT-type earthquakes per day, 25 of these with magnitudes bordering on 2.5. Recorded on the previous two days were five groups formed by a pair of VT-type earthquakes whose magnitudes (2 and 2.5) and time intervals (9-11s) were repeated. Today, 2 July 2008, there was a slight decrease in the number of earthquakes with magnitudes greater than 2 (12 events), while the total number of earthquakes reached approximately 150.

3. CONCLUSIONS
The gradual increase in earthquakes that has been verified over the past four days culminated in the formation of a new emission centre, which has increased the rate of emission and, accordingly, the height of the eruption columns. Today there were only 12 earthquakes recorded with magnitudes bordering 2.5. The diminution of earthquakes with magnitudes greater than 2.5 can be related to the opening of the new emission centre.

4. RECOMMENDATIONS
SERNAGEOMIN maintains Volcanic Red Alert and will continue with visual surveillance and the processing, analysis and interpretation of related seismicity.

The most interesting piece of information here, slipped in under ‘conclusions’, is the formation of a new emission centre (’la conformación de un nuevo centro de emisión’), that is, the opening of a new eruptive vent. There are no further details about this that I can find anywhere, and no reference in earlier reports. This reference today is the first confirmation that a new vent has opened, although such a development is consistent with both the recent rise, then drop, in seismicity, and the increased height of the eruption column yesterday. Buenos Aires VAAC was reporting heights of 12000 to 15000 feet (3600 to 4500 metres) yesterday morning; this has since fallen back to 10000 feet (3000 metres).

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)