Volcanic landslides that generate huge and devastating tsunamis tend to occur during historically warmer times on Earth, a new study suggests. Scientists don't know exactly why, but since the global climate is warming as you read this, the apparent connection was tossed out this week as a reason for scientists to be concerned about the threat now.Tsunamis are waves that race across the ocean without much fanfare but grow to frightening proportions when they reach land. The waves are deep, and while they may appear just a few inches or feet tall on the open ocean, they can soar to the height of a multi-story building as they are forced upward near the shore.A tsunami can be generated by the sudden uplift of the seafloor in an earthquake, or by the paddle-like effect of a landslide crashing into the sea from, say, an island volcano. Yet while quake-generated tsunamis have been observed from their genesis to the disastrous end, scientists have never witnessed a significant open-ocean tsunami generated by a landslide.Evidence exists at various locations around the world for megatsunamis, as scientists call the largest of these events. They seem to occur every 100,000 years or so, said Gary McMurtry of the University of Hawaii. These monsters can be hundreds of feet tall and, depending on local topography, race miles inland.One controversial event, about 110,000 years ago, appeared to create a 1,600-foot wave in Hawaii. Yes, you read that right: Nearly one-third of a mile, or about half a kilometer. But the evidence -- marine fossils way up there where there's no sea -- is controversial. Perhaps the islands have been rising and carried the fossils up, critics suggest.McMurtry's team looked at marine fossils at the Kohala volcano on the main island of Hawaii, which is known to be sinking about an inch per decade. The fossils simply could not have started at a lower elevation, McMurtry said Monday at a meeting of the American Geophysical Union held here. A submarine landslide from the giant Mauna Loa volcano has been dated to the same time and, the thinking goes, caused the tsunami.
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Wow that's kinda- no scary! Well I for one hope it doesn't happen while I'm still here! I never thought of that happening every 100,00 years! That's interesting! And kinda a scary thought. Maybe I should put my Beanie Babies and Nancy Drew collections up on ebay? Hmmm....
