Pacific Northwest Research Station

» Chaitén Photoessay

Making Science Connections, Worldwide

Since 2009, PNW Research Station scientists Fred Swanson and Charlie Crisafulli have been traveling to Chile to study the effects of the eruption of Chaitén Volcano, a 3,681-foot-tall caldera volcano that erupted violently in May 2008. Their visits, supported by the U.S. Forest Service and the National Science Foundation and carried out in collaboration with Chilean academics, national park officials, and other U.S. and Chilean colleagues, have launched a study to document the ecological responses to the Chaitén eruption and to compare them with those observed in the intensively studied Mount St. Helens landscape. Now in their fourth year, these visits have already begun yielding insight on the response of nearby forests, rivers, and towns to volcanic disturbance—and on the striking similarities between volcanic landscapes and their responses in the northern and southern hemispheres.

Browse this site to learn more about the changes observed in Chile so far and how Crisafulli and Swanson are making connections between their work at Mount St. Helens and at Chaitén.

The Eruption at Chaiten

Remote sensing image with locations.

Chaitén is a small volcano located in Pumalin Park, in the southern part of Chile. Prior to Chaitén’s 2008 eruption, which followed several days of earthquake activity, many nearby residents and visitors did not know that the 962-meter-tall (3,156 feet) flat-topped structure was a volcano, which added to their surprise when it erupted. The eruption itself attracted attention worldwide—as it was the first major rhyolite eruption in nearly a century anywhere on Earth. Initially, it launched fine-grained rock debris more than 20 kilometers (65,000 feet) into the atmosphere. Over the following months, the volcano maintained an eruption column several kilometers high and exhibited intermittent periods of more explosive phases. Wind blew plumes of tephra in a broad arc to the east across Argentine Patagonia and the Atlantic Ocean.

Sometime during the first week of the eruption, a blast cloud of hot rock debris surged down the north flank of Chaitén, knocking down trees and scorching foliage on trees around the edge of a 4 km2 zone. Intense rainfall began about 10 days after the start of the eruption and washed a great deal of tephra from the surrounding hillslopes, sending sediment-rich flood waters into streams and rivers. The volcano’s lava dome grew within the caldera in the two years immediately following the eruption.

Research Trips

Remote sensing image with locations.

January 2012 will mark the fourth consecutive year that station scientists Fred Swanson and Charlie Crisafulli and U.S. collaborators have traveled to Chile during the southern hemisphere summer to document the ecological impacts of the eruption on nearby forests and rivers and to investigate the pace and pattern of plant and animal response.

The landscape affected by Chaitén’s 2008 eruption has remained dynamic since the eruption.

Plant survival was widespread, but varied dramatically based on the types and intensities of volcanic disturbance.

Several species of trees in the former forest that were leveled by the powerful blast sent out new shoots as early as the first post-eruption growing season. The success of this regrowth is not known, but is a topic of investigation. By the third post-eruption growing season, numerous species of plants and animals had established in the affected areas. These included tree, shrub, and herb species as well as animals such as birds, amphibians, insects, and spiders.

Sediment production remains above pre-eruption levels. Four bridges in the vicinity of the town of Chaitén offer views of the volcano and the surrounding rivers and forests that were affected by the 2008 eruption. These locations provide ideal vantage points for telling the stories of the volcano’s eruption and its aftermath.