Here’s a fascinating video about the 1980 eruption of Mount St. Helens, which was preceded by one of the largest landslides in recorded history. Amateur photographer Keith Ronnholm had set up camp that day at Bear Meadows, roughly 10 miles northeast of the mountain.
At around 8:30 in the morning, a magnitude 5.1 earthquake triggered a massive landslide that wiped out the north face of the volcano, with the entire surface moving at up to 115 miles per hour. Pat Forgey of the The Daily News has an interesting account from Ronnholm’s perspective:
Looking up, Ronnholm saw a lot more than what he’d come for. “The entire north face of the mountain, what was called the ‘bulge,’ was sliding down,” he said. At first forgetting he’d come to take photos, Ronnholm hesitated getting his camera. “I thought, ‘I’ll never get it focused in time, this is all happening too fast,’ ” he said.
Standing third ridge removed from the mountain, Ronnholm thought he had a good spot to view the geologic event of a lifetime. He began snapping pictures with his 35mm Minolta as a lateral blast shot out of the volcano and swirled and boiled toward him. Ronnholm said he was not worried.
Thanks to the photographs of the event captured by Ronnholm and a few other photographs on the scene (notably Gary Rosenquist), scientists have been able to reconstruct what the landslide looked like.
At the end of the video above, we see a rendering of what it looked like, created by filling in the gaps found in the photos captured that day. Here’s another one:
Ronnholm, Rosenquist, and their photographs survived because the landscape deflected the volcanic blast around 1 mile short of their location. As we shared back in 2011, another photographer named Robert Landsberg wasn’t so lucky — he died protecting his film and photographs.