Eruption threat remains at Nevado del Huila 6 February 2009Posted by admin in activity reports, Colombia, natural hazards, Nevado del Huila, volcano monitoring.
Tags: Colombia, natural hazards, Nevado del Huila, volcanic activity reports, volcano monitoring
In Colombia, Nevado del Huila volcano continues to cause concern. On 3 February 2009 the Observatorio Vulcanológico y Sismológico de Popayán, the observatory operated by the Instituto Colombiano de Geología y Minería (INGEOMINAS) which monitors Nevado del Huila, issued a bulletin for the period 28 January to 3 February 2009, incorporating observations from an overflight made by observatory staff on a Colombian Air Force plane on 28 January. Among the observations made in the statement are:
- Elevated seismicity, with 461 seismic events recorded: ‘Of these, 172 are related to fracturing of rocks, 269 to the movement of fluid within the volcanic conduits, three hybrids and 17 pulses of low-magnitude tremor’. The rock-fracturing events included three quakes of magnitudes ranging between 2.0 and 3.5, two at a depth of less than 4km.
- During the overflight continuous degassing was observed from the upper part of the lava dome, producing gas columns of blue and white colouring, indicating discharges of steam and sulphur dioxide.
- Web camera images from 28 and 31 January showed gas columns not exceeding 1000m altitude and dispersing to the south-east.
- Sulphur dioxide emissions were measured on 3 February and calculated to be at a rate of 2148 tonnes per day.
- Observations show that the new dome on the south flank of Nevado del Huila’s main peak, Pico Central, is continuing to grow.
A video of the 28 January overflight is available from the Popayán observatory main page, or via this direct link (.mpg, 17.2MB). The Nevado del Huila webcam, provided by the USGS, can be viewed through this link.
Above: General view of Nevado del Huila looking northwards. The captions have been added for clarity and are not part of the original image. The lava dome is located on the south flank of Pico Central. Below, two closer views of the lava dome, showing constant gas-and-steam emissions.
Semana reports that the Colombian Interior Minister, Fabio Valencia Cossio, visited the town of Belalcázar on 24 January, in the wake of the government’s decision to relocate the town, which is highly vulnerable to lahars from Nevado del Huila. The Minister confirmed that the entire municipality is to be moved to a new site, along with nine nearby indigenous reserves (the homes and livelihoods of indigenous communities have proved particularly vulnerable to the volcano). The timetable for the move is still not clear, although it is evident that the government takes seriously the warnings of the geologists that Huila will erupt again soon, and wishes to move quickly. Local inhabitants whose homes have already been left uninhabitable by November’s floods will be relocated as a matter of urgency.
For all our Nevado del Huila coverage: Nevado del Huila « The Volcanism Blog.
Global Volcanism Program: Nevado del Huila – summary information for Nevado del Huila (1501-05=)
Portal Corporativo de INGEOMINAS – main page for the Instituto Colombiano de Geología y Minería
INGEOMINAS Popayán – main page for the Observatorio Popayán, which monitors Nevado del Huila