July 9, 2011 - Eruption of Puyehue-Cordón Caulle volcano, Chile

Eruption of Puyehue-Cordón Caulle volcano, Chile

A month after the eruption of the Puyehue-Cordón Caulle volcanic complex began, a light gray plume of volcanic gas and ash drifted hundreds of kilometers northwest over the eastern South Pacific Ocean. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Aqua satellite captured this true-color image on July 3, 2011.

Between June 2 and June 3, about 1,450 earthquakes were detected near the volcanic complex, an average of about 60 tremors per hour. On June 4, the seismic activity increased to an average of 230 earthquakes an hour, with several events reaching a Richter magnitude of greater than 4. Later that same day, the volcano began erupting explosively, shooting an ash and gas plume to an altitude of at least 10 kilometers (33,000 feet) above sea level. The initial plume was reported to be 5 kilometers (3.1 miles) wide. Since the initial eruption, the ash cloud circumnavigated the globe at least twice, with the first completed on June 22.

On July 1, the Southern Andean Volcano Observatory (OVDAS) of Servicio National de Geologia y Mineria de Chile (SERNAGEOMIN) reported a white plume rose 3 kilometers (9,842 feet) above the crater. At that time, local news articles reported disruptions of airline flights in Argentina. The white color of the plume was thought to be due to a low quantity of ash.

From June 29 to July 2 the seismic activity was reduced, leading to speculation that the lava flow remained active, but reduced. From July 2 to July 3 seismic signals indicated that the lava flow was significantly decreased or ceased. However, on July 4 high-intensity tremors suggested that the lava flow was active again.

The plumes that rose above the crater on July 2-4 were darker gray, suggestive of increased ash being emitted. The Alert Level at the volcanic complex remains at 6, a Red Alert.

Image Facts
Satellite: Aqua
Date Acquired: 7/3/2011
Resolutions: 1km ( B), 500m ( B), 250m ( B)
Bands Used: 1,4,3
Image Credit: Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC