No reports of injuries, damage from M7.3 quake in northeastern Japan
Areas in northeastern Japan hard hit by the March 11 mega earthquake and
ensuing tsunami were jolted again Sunday morning by a strong earthquake
with a preliminary magnitude of 7.3, the Japan Meteorological Agency said.
There were no immediate reports of injuries or damage from the 9:57 a.m.
quake, which registered 4 on the Japanese seismic intensity scale of 7
in parts of Iwate, Miyagi and Fukushima prefectures including an area in
the Iwate capital of Morioka.
A warning for tsunami of up to 50 cm was issued for Pacific coastal
areas of the three prefectures immediately after the quake, but was
lifted at 11:45 a.m. after 10-cm tsunami waves were observed at Ofunato
port in Iwate at 10:44 a.m. and at Soma port in Fukushima at 11:11 a.m.,
while another 10-cm tsunami reached Ofunato port at 11:20 a.m.,
according to the agency.
It was the first time tsunamis were actually observed in Japan since the
March 11 disaster.
The focus of the quake was about 180 km off the coast of Miyagi
Prefecture at a depth of about 34 km, the agency said, adding the quake
is considered to be an aftershock of the March mega quake.
It was the first time that the agency issued a tsunami warning since
June 23, when a magnitude 6.7 quake shook the northeastern region.
Sunday’s quake was the first in the magnitude 7 class to rock areas
devastated by the March quake since a magnitude 7.0 temblor struck on
April 11.
The agency initially put the preliminary magnitude of Sunday’s quake at
7.1 but later revised it to 7.3.
"(Magnitude 7-class quakes) may occur occasionally between magnitude 3-
to 5-class quakes that could occur frequently," an official at the
agency said in a press conference. "Continued vigilance will be required
over coming years," he added.
Kyodo, July 11, 2011
http://search.japantimes.co.jp/cgi-bin/nn20110711a2.html
March 11 Disaster May Have Boosted Probability of Quake near Tokyo
Tokyo, July 11 (Jiji Press)—The March 11 earthquake may have boosted the probability of a massive earthquake expected to happen at faults in the Miura Peninsula of Kanagawa Prefecture, south of Tokyo, a government panel said Monday.
It seem to have become easier for the faults to move though it is uncertain how much the probability has risen from the existing forecast of 11 pct over the next 30 years, the government’s Earthquake Research Committee said.
The magnitude of the anticipated quake on the open-ended Richter scale is forecast at 6.7 at least. Its maximum seismic intensity on the Japanese scale is seen reaching the highest 7 in the Kanawaga Prefecture cities of Yokohama and Yokosuka.
The Miura faults add to three other groups of faults noted last month by the same panel as those whose quake probability may have increased. The three are the Futaba faults straddling Fukushima and Miyagi Prefectures, the Tachikawa faults straddling Tokyo and Saitama Prefecture and the Gofukuji faults in Nagano Prefecture.
Near the Gofukuji faults, a 5.5-magninude quake struck on June 30. But it is uncertain whether the faults had anything to do with the tremor.
Jiji Press, July 11, 2011
http://jen.jiji.com/jc/eng?g=eco&k=2011071100888