Wade Rogers shares footage of a controlled avalanche event taken from a helicopter. It's amazing to see how an avalanche flows like liquid water. Via Wade:
After a heavy snowfall in Juneau, Alaska, the State's Dept. of Transportation conducted a controlled avalanche drill on the side of Mt. Roberts, using a helicopter and explosives that are dropped from a dispenser that's slung under the chopper. There are 3 avalanches in this video, beginning with the largest and longest. During the first avalanche, the snow continued to slide down the chute for a couple of minutes after the powder reached sea level, so it takes a couple of minutes to get the full scale of this avalanche. It's likely that several hundred thousand tons of snow was moved during just the first event. I shot this at 1080p using a 4K Sony video camera with an internal 3 axis gimbal, mounted to a monopod, while at Sandy Beach in Douglas, Alaska.
Here's another good example out of Washington State:
Image: YouTube / Wade Rogers