Originally posted by TrueAmerican
Larger seismicity has been back on the rise this week:
There's got to be a whole temple of people in Tokyo praying 24/7. I am convinced of this now, because I know of no other way they have escaped a direct hit of a bigger one after all this time.
A year on from one of the biggest earthquakes in recorded history, Japanese scientists are warning anew that Tokyo could soon be hit by a quake that will kill thousands and cause untold damage.
Greater Tokyo, home to 35 million tightly packed people, has seen a three-fold increase in tectonic activity since the magnitude 9.0 undersea quake that unleashed a killer tsunami last March.
The University of Tokyo's Earthquake Research Institute says the city, built at the intersection of four tectonic plates, has a 50 percent chance of suffering a major quake -- anything above a magnitude 7.0 -- in the next four years.
"We must prepare for the earthquake that will happen," says Asahiko Taira, executive director of the government's Japan Agency for Marine-Earth Science and Technology.
Als Folge der Erschütterungen riss die Erdkruste in wenigen Minuten auf einer Länge von 400 Kilometern auf. Teile der Honshu-Küste wurden ruckartig um bis zu fünf Meter Richtung Osten versetzt. Am Rand des Japan-Grabens betrug der Versatz von Teilen der Erdkruste sogar über 50 Meter. Die plötzliche Plattenbewegung hob den Meeresboden auf einer Fläche von der Größe Schleswig-Holsteins um bis zu fünf Meter an. Untermeerische Rutschungen verfrachteten große Gesteinsmassen in den Japan-Graben.
Scientists suspect that the extraordinary force of the tsunami, which killed some 20,000 people, may have been the combined result of the sea floor rising with a jolt by up to five metres and of quake-triggered slides of the Japanese continental shelf.
The team will search for clues of either mechanism: the fine-scaled pattern of horizontal and vertical displacement of the crust beneath the ocean floor and the amount and origin of sediment that may have slid into the 7,000 metre-deep Japan trench will shed light on the fateful chain of events and help constrain the precise source of the tsunami, they hope.
“In the light of the tragic events last year the stability of the continental shelf off Honshu is a key research topic,” says Wefer. “We are glad that we can assist our Japanese colleagues with precious ship time. I hope that this cruise will mark the beginning of a close collaboration between our countries in marine sciences.”
Date-Time Friday, March 09, 2012 at 17:25:33 UTC
Saturday, March 10, 2012 at 02:25:33 AM at epicenter
Time of Earthquake in other Time Zones
Location 36.732°N, 140.528°E
Depth 25.3 km (15.7 miles)
Region NEAR THE EAST COAST OF HONSHU, JAPAN
Distances 40 km (24 miles) N of Mito, Honshu, Japan
47 km (29 miles) SW of Iwaki, Honshu, Japan
61 km (37 miles) ENE of Utsunomiya, Honshu, Japan
135 km (83 miles) NNE of TOKYO, Japan
Location Uncertainty horizontal +/- 12.3 km (7.6 miles); depth +/- 7 km (4.3 miles)
Parameters NST=367, Nph=379, Dmin=209.3 km, Rmss=1.06 sec, Gp= 76°,
M-type=body wave magnitude (Mb), Version=9
The disaster lent credibility to his team's research methodology, prompting others to launch interdisciplinary studies integrating seismology, geology and philology to examine the history of earthquakes over hundreds of years.
Shishikura's team took soil layer samples along the Tohoku coast and checked them against disaster accounts recorded in ancient chronicles. This helped them conclude that major temblors and tsunami repeatedly slam Tohoku over a cycle of between 500 and 1,000 years.
Shishikura had planned to visit the Fukushima Prefectural Government last March 23 to explain this danger. Shishikura's team even drew up maps of the areas flooded by the 869 tsunami and planned to distribute copies to residents along the coast.
The maps turned out to be nearly identical to the areas that were inundated on March 11. "We could have saved some lives if the tsunami had come just a month later," he lamented. Shishikura said his team's approach — studying both soil layers and historical accounts to extrapolate quake cycles over hundreds of years — was regarded as a "minor" technique by seismologists.
Before March 11, mainstream seismologists had mostly focused on watching and analyzing real-time data from observation equipment tracking tectonic plate and ground movements. This led them to focus only on temblors from the past 100 years or so, because that's as far back as the available data went, Shishikura said.
But in the wake of March 11, a panel under the government's Central Disaster Management Council in June adopted a new interim report signaling a clear departure from traditional seismology. The report recommended that the government prepare for a "worst case" earthquake and tsunami combo that could strike in a cycle extending over hundreds or even thousands of years.
"To confirm occurrence of gigantic tsunami over thousands of years, it's important to strengthen integrated research from not only seismology, but also archaeology, historical science and surveys of tsunami sediment, soil and animal fossils," the report said.
Originally posted by Alekto
First time poster, in Tokyo. I would like to bail but the wife is 8 months pregnant with our first child.
Am fretting non-stop over this.
Date-Time Thursday, March 15, 2012 at 19:20:18 UTC
Friday, March 16, 2012 at 04:20:18 AM at epicenter
Time of Earthquake in other Time Zones
Location 35.794°N, 139.213°E
Depth 99.9 km (62.1 miles)
Region NEAR THE SOUTH COAST OF HONSHU, JAPAN
Distances 50 km (31 miles) WNW of TOKYO, Japan
53 km (32 miles) NW of Yokohama, Honshu, Japan
58 km (36 miles) ENE of Kofu, Honshu, Japan
67 km (41 miles) S of Maebashi, Honshu, Japan
Location Uncertainty horizontal +/- 11.9 km (7.4 miles); depth +/- 8 km (5.0 miles)
Parameters NST=255, Nph=279, Dmin=123.6 km, Rmss=1 sec, Gp= 83°,
M-type=body wave magnitude (Mb), Version=5
Source Magnitude: USGS NEIC (WDCS-D)
Location: USGS NEIC (WDCS-D)
Event ID usb0008hu0