A pyroclastic flow produced by collapse of a growing lava dome sweeps down the flanks of Alaska's Augustine volcano on August 28, 1986. These high-temperature, high-velocity flows commonly travel silently because the sound of the moving blocks at the base of the flow is muffled by dense columns of gas and ash that roil up above the flow. This photo was taken at a distance of about 100 m from the margin of the pyroclastic flow.

Copyrighted photo by Katia and Maurice Krafft, 1986.

Copyrighted image used with permission. All Rights Reserved. Contact photographer for any usage requests.

Augustine