COLORADO—Mount St. Helens erupted with a blast on May 18, 1980, leveling the surrounding forests and taking the lives of 57 people. Layers of ash transformed the landscape from old growth forest to a barren moonscape. Matthew Radcliff, an earth science video producer for NASA, wanted to capture the forest’s recovery 40 years later.
Rocky Mountain Research Station research ecologist Sean Healey uses Landsat data recorded since 1972 to study the long-term impacts of the eruption on the forest. Healey is an expert in the field of remote sensing, specializing in the assessment of disturbance and management impact on carbon storage, and addressing national and international monitoring issues. He has partnered with NASA on many projects, and this video highlights the collaboration between the agencies. On May 18, NASA released 40 Years of Watching Mount St. Helens to commemorate the anniversary of the eruption and to share Healey’s science.
Healey and research partner RMRS computer scientist Zhiqiang Yang have been studying the time series of Landsat data of the forests around Mount St. Helens to determine how the forest structure changes and recovers following such a disturbance. This type of volcanic disturbance is unique and relatively unstudied, and Landsat data provides a fantastic opportunity to study the landscape over time. Healey and Yang developed a model using the Landsat imagery to predict the percent tree cover and document the recovery of the area as trees and other vegetation regrows. They are monitoring the changes in carbon stocks and the dynamics of the forest recovery.
Healey says, “Zhiqiang Yang and I have for many years used remote sensing to support old growth monitoring in the Northwest Forest Plan area. The Mount St. Helens eruption 40 years ago stands out as monumental loss of old growth forests, but it has also showed us how forests start over. The Landsat program has been a great tool for studying this unique event.”
Their new model and insights from the recovery of the forests around Mount St. Helens will guide managers in sustaining our nation’s forests in the face of major disturbances. The Landsat Program, jointly managed by NASA and the United States Geological Survey, is a series of satellites that have been consistently observing the earth since 1972, creating a record of our planet’s changing landscapes.