The powerful earthquake that unleashed a devastating tsunami Friday appears to have moved the main island of Japan by 8 feet (2.4 meters) and shifted the Earth on its axis.
"At this point, we know that one GPS station moved (8 feet), and we have seen a map from GSI (Geospatial Information Authority) in Japan showing the pattern of shift over a large area is consistent with about that much shift of the land mass," said Kenneth Hudnut, a geophysicist with the U.S. Geological Survey (USGS).
Reports from the National Institute of Geophysics and Volcanology in Italy estimated the 8.9-magnitude quake shifted the planet on its axis by nearly 4 inches (10 centimeters).
Japan is in a subduction zone -- the Pacific and Philippine Sea plates are sliding under the North American and Eurasian plates right there. The Japanese archipelago actually seems to have originated as part of the continent, separated by a rift at what is now the Sea of Japan. If you look at a map, it's pretty amazing -- here's what seems to be a decent site on the geology and geologic history of Japan. And here's a diagram of the plate boundaries.
That site's worth checking out if you want to get an idea of why that quake happened.
As for the human reality, I can't wrap my head around what people are going through -- it's just utter and total disaster for those caught in the quake zone and the path of the tsunami. I've experienced a couple of quakes here in Chicago -- very mild, on the edges of the zone -- they were centered in southern Illinois and Indiana, and neither was very strong, but it was still scary as hell -- the building shook for a good thirty seconds and the cats and I all freaked out. To have buildings coming down around you has got to the scariest thing there is. And to have that followed by 60-foot tidal wave? Here's an overview of the devastation from AP. Just reading that, it becomes a little more real, and even more staggering. (And as a footnote, among the things that the Teabaggers don't want to spend money on are the tsunami warning system and humanitarian aid.)
And now they're faced with the possibility of a meltdown at one of their nuclear power plants. Why would anyone build nuclear power plants in a place as earthquake-prone as Japan? Because people don't think very much.
Footnote: I was talking about Hawai'i the other day, and how it's sitting on a volcanic hot spot in the middle of the Pacific. If you want to see how the Pacific plate has moved over the past few million years, take a look at this:
Notice that long string of seamounts that starts in the middle of the Pacific Ocean and stretches all the way up to the Aleutians. Those have all been Hawai'i. (This is from the site linked above.)
No comments:
Post a Comment