Chaitén: Volcano with a Mission?

Dormant for 9,500 years, Chaitén recalled to service by nature

Continuing Activity at Chaitén Volcano

Chaitén Volcano, southern Chile, 42.833°S, 72.646°W; summit elev. 1122 m. False-color images: Red indicates vegetation; deep blue water and off-white is the plume from the volcano. Image: Earth Observatory. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite captured the above image of Chaitén Volcano on January 19, 2009. the two versions of the image posted here are (uppermost) a close-up view, and (top) a view with the surrounding area.

1. After about 9,500 years of dormancy, as if recalled to service by nature, Chile’s Chaitén Volcano erupted violently on May 2, 2008.  The volcano has since continued intermittent activity,  spewing plumes of ash and steam into the atmosphere and ejecting pumice across Patagonia.

2. Lahars from the volcano inundated a coastal town of the same name (population 4,300), whose inhabitants were evacuated last year.

3. Chile’s  SERNAGEOMIN reported an increase in Chaitén’s seismic activity  during 9-12 January, global Volcanism said. “The unstable slopes of Domo Nuevo 2 and spine collapses continued to produce block-and-ash flows. Based on SIGMET notices, analysis of satellite imagery, and web camera views, the Buenos Aires VAAC reported that on 15, 17, 19, and 20 January ash plumes rose to altitudes 1.5-2.1 km (5,000-7,000 ft) a.s.l. and drifted NE, E, and SE. A small thermal anomaly was detected in satellite imagery on 19 January.”

4. “When the Philippine’s Mount Pinatubo erupted in June 1991, it was a tremendous, explosive eruption that buried the surrounding countryside in a thick layer of ash and mud and pumped a cloud of ash and gas high into the atmosphere. Sulfur dioxide rose high into the stratosphere 34 kilometers above Earth’s surface and circled the globe. The gas combined with water to form a fog-like screen of sulfate aerosols that shielded Earth’s surface like a giant shade, and for more than a year the global average temperature dropped by 0.5 degrees Celsius.” EO said.

5. When Chaiten erupted on May 2, 2008, some experts beileved that it was unlikely that it would have an effect on global temperatures.

6. Firstly, Chaiten did not released a large amount of sulfate aerosols into the atmosphere.

7. Secondly, its location was unfavorable. Because it was located in southern Chile far from the equator, its impact would be limited. “Most of the volcanoes that have influenced global temperatures are located in the center of the globe near the equator. Winds in the stratosphere in the tropics quickly circulate sulfate aerosols around the globe. By contrast, stratospheric winds near the poles tend to push sulfate aerosols towards the poles and towards the surface, limiting the area influenced by the aerosols.” EO said.

8. Chaiten was therefore deemed as unlikely to influence global temperatures even if the sulfur dioxide coming from the volcano were higher.

9. However, as Chaiten continues to remain active, it would only be a matter of time before its full impact on the climate is known.

Related Links:

• Chaitén: Volcano that Doesn’t Sleep
• Chaitén’s Fury Ending?
• Philippines Taal Volcano Could Erupt Anytime!

• The Power of Chaitén Volcano
• Chile: Volcano activity prompts mass evacuation
• Chaitén Volcano: No End Seen to Second Massive Eruption

Possibly related links:

• Calendar year 2008 was the coolest year since 2000, according to GISS

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