Galapagos Islands Volcano - Sierra Negra

Sierra Negra Volcano, on the Galapagos Island of Isla Isabela, has been erupting since October 22. The image below shows a heavy plume of volcanic ash and steam streaming from the volcano to the southwest. Lava flows have descended the northeast side of the mountain but have not threatened people or rare species such as the giant tortises and land iguanas.

Augustine Volcano Eruption (Alaska)

Augustine Island Volcano, located in southern Cook Inlet, about 100 km WSW of the town of Homer on the Kenai Peninsula and nearly 300 km SW from Anchorage, is erupting now after about 18 years of inactivity. The current eruption is producing ash but USGS is concerned that a large blast might occur. Augustine's symmetrical cone rises 1,254 meters above sea level. It was named by Captain James Cook in 1778 and has erupted in 1812, 1883, 1935, 1963-64, 1976, and 1986. An eruptive blast in 1883 produced a large landslide which ran out to the ocean, extending the island's north shorline as far as 2 kilometers and producing a small tsunami that swept across Cook Inlet.Augustine's 1986 eruption began with a violent explosion on March 26th. This sent ash plumes to more than 10 kilometers above the vent and triggered pyroclastic flows that sped down the volcano's flanks into the sea. A second stage began on April 23 when lava began erupting near the volcano's summit and added about 25 meters to the top of the existing lava dome. Small pyroclastic flows accompanied growth of the dome.

Eruption at Tungurahua Volcano Ecuador

Tungurahua Volcano, a stratovolcano in central Ecuador is erupting again. This volcano has a history of sudden strong explosions, lava flows, lahars and pyroclastic flows that have reached populated areas near its base. Early this morning Tungurahua erupted with a powerful explosion, launching hot rocks and ash into the air and producing a lava flow that spread into populated areas. Thousands have been evacuated and remain at a safe distance even though the activity subsided quickly. Scientists at the National Geophysics Institute expect more explosive activity over the coming days or weeks.

Mayon Volcano Hangs on Edge of Eruption

In early August, the Philippine Institute of Volcanology and Seismology recommended an evacuation of thousands of people who live within a danger zone surrounding Mayon volcano and the Philippine government responded with an evacuation order (see our previous post).Mayon continues its activity and remains dangerous in the opinion of the PIVS. The evacuated people remain in numerous temporary evacuation centers which provide uncomfortable accommodations which are expensive for the government to maintain.One of the main causes for concern is the possibility of pyroclastic flows (deadly clouds of hot gases and ash that can flow down the flank of the volcano at great speeds and run several miles from the volcano's base). During an eruption in 1993, seventy seven people were killed by Mayon's pyroclastic flows. The images (below and right) show pyroclastic flows descending Mayon during a 1984 eruption.

One of the best satellite images of a volcano that I have ever seen is now on display at NASA's Earth Observatory website. Tungurahua Volcano in Ecuador has been erupting or restless for the past several months. Lava flows and pyroclastics have blanketed much of the surrounding landscape, forced evacuations of many villages, dammed the Chambo River and caused numerous fatalities and injuries.Tungurahua is one of the most active volcanoes in Ecuador, but many people decide to live on its flanks because of the rich soils and mild temperatures. The price for this has been abandonment of property and the risk of injury or death. Visit the Earth Observatory website to see this great Volcano Image.