Global Volcanism Program | Image GVP-05241
Hot debris avalanching down the steep north flank of Redoubt Volcano during the 1989-90 eruptions mixed with water derived from melted snow and ice to form lahars. These sediment-rich floods carried steaming debris many kilometers down the Drift River Valley. The top of the gray area marks the high-water line of the lahar that contrasts with the snow-covered slopes above it. Note the helicopter for scale.
Photo by Tom Miller, 1990 (Alaska Volcano Observatory, U.S. Geological Survey).