On 2 May 2008 an old volcanic caldera erupted close to the coastal town of Chaitén in southern Chile.
28 September 2022
05 May 2008
By HansPeter Roesli and Jochen Kerkmann (EUMETSAT)
More than 9,000 years after the last eruption, huge amounts of ash and gases were ejected to great heights for several days (activity is ongoing even even months after the first eruption).
With Meteosat-9's sensitivity to ash and SO2 their transport across the Southern Atlantic into the Indian Ocean could be monitored over several days. The hourly Meteosat-9 animation (3 May 06:00 UTC–06 May 09:00 UTC) shows the initial evolution in a sequence of the standard RGB enhancing the presence of ash and SO2. The 3-hourly Meteosat-9 animation (3 May 00:00 UTC–09 May 06:00 UTC) is a longer sequence at lower temporal resolution but spanning three more days and the whole part of the southern hemisphere covered by Meteosat-9.
Three frames taken from the latter animation are used to single out a couple of SO2 signals that tag the general circulation over the area. On frame 1 (4 May 6:00 UTC) the upper red arrow marks a pink-coloured ash plume and the lower red arrow shows the approximate position of a SO2 cloud. The blue arrow points to a second, light green SO2 plume.
Two and a half days later, on frame 2 (6 May 21:00 UTC) the two SO2 clouds of the former frame move over to the longitude of South Africa with the respective trajectories (red arrow now north of blue one). At the same time, over the Argentinean Atlantic coast yet another Chaiten plume (white arrow) is appearing again carrying ash and SO2.
While the SO2, marked with red and blue arrows, appear to merge moving further into the Indian Ocean, on frame 3 (9 May 03:00 UTC) the SO2-part of the Argentina plume has moved on a more southern track (white arrow) than the patches seen before. New ash plumes continue to cover the coast from Argentina to southern Brazil. There are other SO2 patches in the sequence that can be followed.
All in all, the trajectories indicate clearly the meandering circulation, much in contrast to the SO2 tracks over the North Atlantic following the Kasatochi event in August 2008.
Other Chilean volcano cases
Eruption of Calbuco Volcano, Chile
Chile’s Calbuco volcano unexpectedly erupted for the first time in more than 40 years in late April 2015.