The alert level for an Alaska volcano is being raised after officials say persistent thermal anomalies have been spotted in satellite data. The Alaska Volcano Observatory on Wednesday raised the level Cleveland Volcano to advisory from unassigned. Read more
At 3:00 p.m. Alaska Daylight Time on May 23, 2006, International Space Station (ISS) Expedition 13 Flight Engineer Jeff Williams contacted the Alaska Volcano Observatory (AVO) to report that the Cleveland Volcano had produced a plume of ash. Shortly after the activity began, he took this photograph. This picture shows the ash plume moving west-southwest from the volcano’s summit. The event proved to be short-lived; two hours later, the plume had completely detached from the volcano. The AVO reported that the ash cloud height could be as high as 6,000 meters above sea level.
Credit NASA
Cleveland Volcano, situated on the western half of Chuginadak Island, is one of the most active of the volcanoes in the Aleutian Islands, which extend west-southwest from the Alaska mainland. It is a stratovolcano, composed of alternating layers of hardened lava, compacted volcanic ash, and volcanic rocks. At a summit elevation of 1,730 meters, this volcano is the highest in the Islands of the Four Mountains group. Carlisle Island to the north-northwest, another stratovolcano, is also part of this group. Magma that feeds eruptions of ash and lava from the Cleveland Volcano is generated by the northwestward movement of the Pacific Plate beneath the North American Plate. As one tectonic plate moves beneath another—a process called subduction—melting of materials above and within the lower plate produces magma that can eventually move to the surface and erupt through a vent (such as a volcano). Cleveland Volcano claimed the only known eruption-related fatality in the Aleutian Islands, in 1944.
The 1730 metre Cleveland Volcano in the Aleutian Islands erupted a 6700-metre high ash cloud on Monday. Satellites managed to detected the cloud. The Federal Aviation Administration issued a temporary flight restriction in a cylindrical area around the volcano below 50,000 feet and within a roughly six-mile radius. There are no inhabited communities nearby.
"In terms of people on the ground there isn't a danger, but the air traffic out there can be highly affected" - Janet Schaefer, geologist with Alaska's Division of Geological and Geophysical Surveys.
Location: 52.49N, 169.57W Mount Cleveland is a symmetric stratocone which has been frequently active during the 20th century. The volcanic edifice forms the western half of Chuginadak Island located about 40 km west of Umnak Island in the Central Aleutians about 1,525 km southwest of Anchorage.
Cleveland, on uninhabited Chuginadak Island, last erupted in July. Normal eruption activity includes short-lived explosions of ash from the summit. Ash from the volcano has blocked air routes in the past. It's the second volcano to erupt in Alaska this year. Augustine Volcano in south-central Alaska began spewing ash in mid-January.
Three Alaska volcanoes, including two located on remote Aleutian islands, are setting off frequent tremors and minor bursts of ash or steam. Cleveland Volcano, 900 miles southwest of Anchorage, had a small eruption on Friday. An ash plume rose to a height of nearly 15,000 feet above sea level.
Ash emissions from the Volcano "are a lot easier to see now than they were in the summer because you have fresh snow" - Dave Schneider, a U.S. Geological Survey volcanologist.
The Volcano has had periodic but minor ash emissions and some debris flow caused by melted snow Cleveland Volcano, which comprises the western half of uninhabited Chuginadak Island, last erupted in 2001. The closest community, 45 miles to the east, is Nikolski, an Aleut village of 36 people.
A cloud of steam from the 11,070-foot Mount Spurr was visible from Anchorage, 75 miles away. A series of eruptions in 1992 showered Anchorage and the surrounding region with ash, forcing a brief closure of Anchorage International Airport.
The other volcano showing signs of unrest is 5,925-foot Tanaga Volcano.