- Who
- Osceola Mudflow
- What
- 3000000000 cubic metre(s)
- Where
- United States (Mount Rainer)
The largest volcanic mudflow was the Osceola Mudflow, which occurred some 5,600 years ago and began on top of Mount Rainier in the US Cascade Mountain range. The result of a volcanic eruption, it consisted of a debris flow of around 3 km³ (105,944 ft³) that hurtled down the mountain at around 90 kph (56 mph). By the time it had reached the Puget Sound, more than 100 km (62 miles)away, the mudflow still had a thickness of around 30 m (98 ft). After it had subsided it had created 460 km² (177 miles²) of new land on the coast.
