Alutian Islands Valcanos: Mount Cleveland and Kasatochi

Mount Cleveland, also known as Cleveland Volcano and Chuginadak, is one of the most active volcanoes in the central part of the Aleutian island arc. It is a stratovolcano that comprises the entire western half of Chuginadak Island. The portion of the volcano that is above sea level is about 8.5 kilometers in diameter (5.3 miles) and rises to an elevation of 1,730 meters (5,675 feet).

The volcano has been the site of recurrent eruptions throughout the recorded history of this area. It has produced many eruptions since 2000. Ash plumes from these eruptions are a threat to air traffic between North America and Asia. Volcanic ash can damage the exterior of an aircraft. It can also be pulled into jet engines where it melts, accumulates and can cause engine failure. 

NASA - Cleveland Volcano, Aleutian Islands 

Four Mountains, an island grouping of the Aleutian Islands in Alaska, United States. The chain includes, from west to east, Amukta, Chagulak, Yunaska, Herbert, Carlisle, Chuginadak, Uliaga, and Kagamil Islands. The two largest islands are Yunaska and Chuginadak. Chuginadak is mainly made up of the active volcano Mount Cleveland

Snow Capped Volcanoes, Four Mountains in Alaska's Aleutian Island Chain. 

On August 7, 2008, Kasatochi began erupting explosively with an ash plume maintaining an altitude of 35,000 feet and reaching 45,000 feet. As the eruption became imminent, it forced two biologists from the U.S. Fish and Wildlife Service to evacuate the island.] An ashfall advisory was issued at the time for Adak Island. Prior to 2008, the last confirmed activity at Kasatochi was in 1899, but that was not believed to be an eruption. After the 2008 eruption the life on Kasatochi appears to have been destroyed. A research project was started in 2009 in order to study ecosystem impact and long-term recovery.

Kasatochi volcano, Aleutian Islands