Digital elevation model of South Fork Toutle River, Mount St. Helens, based on June–July 1980 airborne photogrammetry
The lateral blast, debris avalanche, and lahars of the May 18th, 1980, eruption of Mount St. Helens, Washington, dramatically altered the surrounding landscape. The eruption produced mudflows in the South Fork Toutle River basin, which drains the western slopes of the volcano. Orthophotography was acquired shortly …