The movement is four times larger than any previous land shift recorded in Japan.
The largest quake in Japan's recorded history also elevated the seabed off the coast of Miyagi prefecture by 3 meters, the coast guard said on Wednesday.
www.reuters.com...
The Korean peninsula shifted 2.3 cm to the east following the devastating earthquake in Japan on March 11 and has not returned to its original position.
The National Geographic Information Institute in collaboration with other institutions such as the Korea Astronomy and Space Science Institute analyzed the movement of the Korean land mass due to the Japanese earthquake and said Wednesday the peninsula shifted 2.3 cm east, while Ulleung Island shifted 4.5 cm and the Dokdo islets 5.4 cm to the east
english.chosun.com...
Scientists estimate that tens of meters of slip took place along the rupture zone. This slip suddenly and permanently uplifted some areas of the seafloor and down-dropped others, causing corresponding vertical movement of the overlying water.
soundwaves.usgs.gov...
Scientists are currently analyzing the wealth of data collected during the earthquake and tsunami, and their preliminary findings have shed some light on why the tsunami was so large. Several factors contributed to the tsunami's enormous size, including the magnitude, depth in the Earth's crust, and overlying water column of the triggering earthquake.
Wave heights are highly exaggerated in these screen shots from computer animations of the tsunami generated by the March 11, 2011, magnitude 9.0 earthquake. View northward in top image, southward in bottom image. walrus.wr.usgs.gov...
Last month's massive earthquake that devastated Japan's northeast shifted the seabed near the epicenter by 24 meters (79 ft), the coast guard said.
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A survey has found that more than 500 square kilometers of land was ravaged by the tsunami triggered by the earthquake on March 11th.
The semi-public Geospatial Information Authority on Saturday announced its survey results based on aerial and satellite images.
It says the tsunami flooded a total of 507 square kilometers of land in the 4 prefectures of Aomori, Iwate, Miyagi and Fukushima. This is equivalent to almost a quarter of the entire Tokyo Metropolitan Area.www3.nhk.or.jp...
Tsunami waves topped 60 feet or more as they broke onshore following Japan’s earthquake, according to some of the first surveys measuring the impact along the afflicted nation’s entire coast. Some waves grew to more than 100 feet high, breaking historic records, as they squeezed between fingers of land surrounding port towns.
The tsunami was born when the magnitude-9.0 earthquake struck March 11 about 45 miles off Japan’s coast. The U.S. Geological Survey said the quake lifted and then dropped a slab of seafloor 50 miles wide and more than 180 miles long. The force shifted the seafloor nearly 80 feet westward above the quake center.
Within a half-hour, the waves arrived on Japan’s coast, plateaus of water that surged up to six miles inland and unleashed much of the devastation that killed about 14,300 people, with another 12,000 still missing. The new estimates on wave heights from the United Nation’s Intergovernmental Oceanographic Commission, gathered from Japanese university surveys, show the biggest waves hit the hilly harbor towns north of where the quake was centered. The surge grew in between inlet hills to 124 feet high at the fishing port of Koborinai
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"I look out the window, and it's like our houses are in the middle of the ocean," says Takahashi, who moved in three years ago.
The March 11 earthquake that hit eastern Japan was so powerful it pulled the entire country out and down into the sea. The mostly devastated coastal communities now face regular flooding, because of their lower elevation and damage to sea walls from the massive tsunamis triggered by the quake.
In port cities such as Onagawa and Kesennuma, the tide flows in and out among crumpled homes and warehouses along now uninhabited streets. www.google.com...
Scientists say the new conditions are permanent.
Japan's northern half sits on the North American tectonic plate. The Pacific plate, which is mostly undersea, normally slides under this plate, slowly nudging the country west. But in the earthquake, the fault line between the two plates ruptured, and the North American plate slid up and out along the Pacific plate.
The rising edge of plate caused the sea floor off Japan's eastern coast to bulge up — one measuring station run by Tohoku University reported an underwater rise of 16 feet (5 meters) — creating the tsunami that devastated the coast. The portion of the plate under Japan was pulled lower as it slid toward the ocean, which caused a corresponding plunge in elevation under the country.
Some areas in Ishinomaki moved southeast 17 feet (5.3 meters) and sank 4 feet (1.2 meters) lower. www.google.com...
Japan's 11 March mega-quake shifted the ocean floor sideways by more than 20m (65ft), according one instrument placed on the seabed off the nation's coast.
This direct measurement exceeds the displacement suggested by some models built only from data gathered on land.
The figure was recorded by the Japan Coast Guard which maintains underwater geodetic equipment along the fault responsible for the giant tremor. www.bbc.co.uk...
