The largest island in a lake on an island in a lake on an island is a nameless 1.6-hectare (4-acre) island at 69Â°47â²35â³N 108Â°14â²28â³W / 69.793Â°N 108.241Â°W / 69.793; -108.241, 121 kilometres (75 mi) inland from the south coast of Victoria Island, Canada.
A tsunami can travel across the open ocean at about 500-miles per hour, the speed of a jet airliner. As the wave approaches land and as the ocean shallows, the wave slows down to about 30 miles-per-hour and grows significantly in height (amplitude).
Waves of Destruction: History's Biggest Tsunamis. Devastating Waves These series of traveling ocean waves are primarily generated in association with underwater earthquakes (though underwater volcanic eruptions and landslides can also trigger a tsunami). In the deep ocean, the waves can reach hundreds of miles or more from wave crest to wave crest and can exceed speeds of 500 miles per hour (805 kilometers per hour). And they're sneaky, unable to be felt even aboard ships, and undetectable from the air. Here are some of the biggest, most destructive and deadliest tsunamis on record.