Eruption of Kasatochi Volcano
The August 7, 2008 eruption of Alaska's Kasatochi Volcano completely covered Kasatochi Island with several meters of ash and volcanic material. It killed all of the islands plants, fish and animals - it virtually sterilized the island. This ecological event also provided a rare research opportunity - a chance to see how species recolonize the island.
Now researchers from the U.S. Geological Survey and the U.S. Fish and Wildlife Service plan to study Kasatochi, visiting the island to look for signs of life.
Volcanic Island Ecology
"Since volcanism plays such a big role in shaping the Aleutians, we hope to end up with a better understanding of how disturbances such as volcanic eruptions shape the ecology of these islands," says Tony DeGange, a USGS scientist at the Alaska Science Center and one of the research team coordinators. "There hasn't been a study quite like this done in Alaska where scientists are taking such a comprehensive ecological view of the impact of an eruption and its resulting response and recovery."
Researchers expect that insects and birds will be the first animal species that recolonize the island. In preparation for the August survey, biologists set up monitoring and sampling equipment on Kasatochi earlier this summer, including insect traps for Derek Sikes, curator of insects at the University of Alaska Museum of the North. Sikes visited Kasatochi in June 2008 for a one-day survey of the insect fauna on the island before the eruption. He will be part of the research team that visits the island next week.
"Work in similar systems shows that flying- and wind-borne insects and spiders form a fairly constant rain during the summer months," says Sikes, adding that some of these species survive by preying or scavenging on other arthropods. "We'll be looking for spiders, which are all predators, and ground beetles, which are mostly predators, as well as other species associated with bird droppings or vertebrate carrion."
A Rare Opportunity to Study a Recolonization
An opportunity like this is extremely rare, according to Sikes. The most comparable example is the emergence of Surtsey Island off the coast of Iceland in 1963, when undersea volcanic eruptions reached the surface. That island was declared a United Nations World Heritage Site for its role as a pristine natural laboratory. Even today, access to Surtsey remains restricted to a small number of researchers each year who study the species that have colonized the island over the past 40 years.
According to the USFWS, the Kasatochi study is unique in that it takes place in an isolated marine ecosystem for which there are pre-eruption ecological data for the island and its nearby marine waters, including data from the Alaska Maritime National Wildlife Refuge dating from the mid-1990s and from Sikes' 2008 field work on the island.
This study is being funded by the North Pacific Research Board, USGS and USFWS. According to DeGange, it is expected to be the first phase of a long-term ecological study.
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|Summit crater and crater lake of Kasatochi volcano, August 6, 2008, the day before the eruption. The crater shown here is about 4,000 feet in diameter. Photo by Chris Ford, USFWS. Larger Image|
|Kasatochi volcano as seen from an aircraft flying at 17,000 feet above sealevel on October 23, 2008. Image by Jerry Morris, Security Aviation. Larger Image|
|Kasatochi volcano, Alaska, after its eruption on Aug. 7, 2008. This near-infrared image acquired on September 23, 2008 shows a barren island. Image by NASA's Terra Satellite.
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|The ash plume from Kasatochi Volcano spreads southeastward over the Pacific Ocean in this August 8, 2008 image from NASA's Terra Satellite. Larger Image|