Chaitén update, 27 March 2009 27 March 2009Posted by admin in activity reports, Chaitén, Chile, eruptions.
Tags: Chaitén, Chile, South America, volcanic activity reports, volcanic eruptions
Chaitén volcano at sunset on 17 March 2009: close-up of the pinnacle and lava dome (photograph by Nicolas La Penna, Chaitur.com).
SERNAGEOMIN have a summary of a new Chaitén bulletin on their website, dated 25 March 2009 and covering the period 17-23 March, but the full document has apparently not yet been made available. As soon as I have a copy, I will post a full translation. The main points from the summary bulletin are:
- Constant degassing and steam emission, with varying ash content, continues at the dome complex.
- Gravitational collapses of unstable areas of the dome continue, possibly slightly increased in number, causing block-and-ash flows.
- Dome growth appears to be restricted to the central-southern area, where the tall central spine and a significant portion of dome 1 are located.
- The central spine is very tall, unstable, and shows very high temperatures.
- Block-and-ash flows continue to generate ash plumes which disperse mainly to the north and east-south-east.
- There has been a significant decrease in seismicity, with fewer hybrid (‘HB’) earthquakes and lower magnitudes, suggesting a slowing in the rate of dome growth.
- The dangers of further dome/pinnacle collapses generating debris flows and lahars along the Chaitén river valley remain.
- SERNAGEOMIN is maintaining Volcanic Red Alert.
In other Chaitén news, the Chilean Government has announced that planning for the ‘new Chaitén’ at Santa Barbara will be completed this year, with full-scale development of the new town beginning in 2010. Basic services at the site are to be installed over the next two months.
Chaitén volcano at sunset on 17 March 2009: view from Chaitén town (photograph by Nicolas La Penna, Chaitur.com).
Many thanks to Nicolas La Penna of Chaitur.com for contributing the photographs that accompany this article. These images clearly show the height and instability of the central pinnacle: note, too, the smaller pinnacle and rough surface of the southern part of dome 1 in the foreground – signs of active lava extrusion – and the constant degassing and steam emission from throughout this section of the dome complex.
For all our Chaitén coverage: Chaitén « The Volcanism Blog.
Global Volcanism Program: Chaitén – summary information for Chaitén (1508-41)
SERNAGEOMIN – Servicio Nacional de Geología y Minería (Spanish)
Erupción del Volcán Chaitén – extensive coverage of the Chaitén eruption