Volcanic ash clouds have been in the news recently, and Iceland is not the only place that is causing problems for the local populace and air travel. In February 2010, islands in the Caribbean were once again affected by an eruption of the Soufriere Hills volcano.
Soufriere Hills volcano is located on the small Caribbean island of Montserrat (Figure 1). In 1995, the previously inactive volcano awakened, initiating a period of eruptive activity that has continued to present. The eruption style of the Soufriere Hills volcano is one of periodic lava dome growth in the volcano's crater, generating an unstable volcanic edifice. When the lava dome collapses, ash clouds are blasted into the sky, usually accompanied by the dangerous nuee ardente (pyroclastic flow), a "glowing avalanche" of ash and gas that sweeps down the side of the volcano at high speed, incinerating and burying everything in its path. The pyroclastic flows from the Soufriere Hills volcano have devastated much of the southern part of Montserrat, leading to numerous fatalities and the evacuation and eventual destruction of the capital city of Plymouth. Only about one-third of the island's pre-eruption population remains, living on the northern end of the island.
For much more information about the volcano and its history, visit the Web site of the Montserrat Volcano Observatory.
Figure 1: Location map and images of Montserrat and the Soufriere Hills volcano
On Feb. 11, 2010, the growing lava dome in the volcano's crater collapsed and sent out a large plume of volcanic ash clouds into to the atmosphere. (NASA Earth Observatory provided the MODIS image of the eruption shown above; see below for a link to the Image of the Day article describing this event.) The global merged IR dataset available at the Goddard Earth Sciences Data nd Information Services Center (GES DISC) documented this event. Figure 2 is an animation of the eastward propagation/dispersion of the ash clouds. Figure 3 is the same animation, but in false color that reveals the temperatures at the top of the ash cloud. Similar to strong tropical thunderstorms, the height of these ash clouds reached the top of the tropopause. This event also disrupted air travel in the Lesser Antilles, the chain of islands that includes Montserrat. (Just a couple of islands south in the chain from Montserrat is the island of Martinique, where a pyroclastic flow from Mount Pelee destroyed the city of St. Pierre on May 8, 1902, killing approximately 30,000 residents.)
Figure 2: Grayscale animation of Merged IR data, showing the ash cloud generated by the eruption of Soufriere Hills volcano, February 11, 2010.
Figure 3: False color animation of Merged IR data, showing cloud top temperatures of the ash cloud generated by the eruption of Soufriere Hills volcano, February 11, 2010.
The animation utilizes the Merged IR dataset, which is a globally-merged (60°N-60°S) pixel-resolution IR brightness temperature data set (equivalent blackbody temperatures), merged from geostationary weather satellites (GOES-8/10, METEOSAT-7/5 & GMS). The data is available (from Feb 2000 and onwards) in Mirador, the data ordering system at the GES DISC. The animations were generated using the Hurricane Data Analysis Tool.
NASA Earth Observatory: Partial Dome Collapse at Soufriere Hills