Quakes strike Asia, but are they linked?
Quakes strike Asia, but are they linked?
TOKYO (Reuters): The earth moved in Asia on Thursday as
powerful aftershocks rocked the west coast of Indonesia's Sumatra
island, and a series of earthquakes jolted China, Myanmar and
Japan.
Experts said last Sunday's quake in Indonesia's Bengkulu
province, measuring 7.9 on the Richter scale, may have led to a
shift in the huge tectonic plates deep under Asia's seas,
prompting the burst of seismic activity this week.
Japan was rocked by three fairly strong earthquakes this week,
while China and Myanmar were each hit by two. Nearly all measured
above five on the open-ended Richter scale.
"It is not unusual to have a sequence of activity on a single
seismic belt, some of it can be quite intense," said C.M. Tam of
the Hong Kong Observatory, referring to the circum Pacific belt
stretching from New Zealand across a wide swathe of East Asia.
Bengkulu's earthquake, which killed at least 120 people,
injured some 1,300 and damaged thousands of homes and buildings,
has spawned around 400 aftershocks, seismologists said.
The Bengkulu earthquake, which appears to have occurred after
a rupture between two key plates -- the Pacific and Indian plates
-- may have triggered a chain reaction of seismic activity along
the circum Pacific and Eurasia belts, the seismologists said.
Professor Ding Jianhai of China's State Seismological Bureau
said the Sumatra, Myanmar and China quakes all occurred along the
Eurasia seismic belt stretching from the Mediterranean sea
through the Himalayas to Indonesia.
He described the belt as "very active" and said he believed
all the tremors were related.
"According to our estimates, there are about average 18
earthquakes at more than seven on the Richter scale globally in a
year, mainly in two belts, the Euroasia belt and the belt around
the Pacific," he said.
Aftershocks from the Bengkulu quake included a major tremor
measuring 6.2 early on Thursday, but most experts expect the
aftershocks and other regional seismic activity to wind down
steadily.
An official at Japan's Meteorological Agency said Japan has
experienced about 20-30 tremors since Sunday's quake in Bengkulu,
although he could not say for sure if they were linked to the
Sumatran earthquake.
"I think they are connected, but it is difficult to say for
sure," he told Reuters.
Japan's latest tremor struck on Thursday at 9:32 a.m. (7:32
a.m. Jakarta time) on the island of Kyushu, and measured 4.9 on
the Richter scale. There were no reports of damage or casualties.
On Wednesday, a tremor measuring 5.8 hit central Japan,
injuring three people but causing no serious damage to buildings.
On Saturday, another earthquake measuring 5.8 swayed buildings
in metropolitan Tokyo, but caused no damage.
Japan sits atop the juncture of three tectonic plates, or
pieces of the earth's crust. Those three plates -- referred to by
geologists as the Asian, Pacific and Philippine plates -- have
been at the heart of recent seismic activity.
Katsuyuki Abe, professor at Tokyo University's Earthquake
Research Institute, however, said linking quakes in Indonesia and
Japan was difficult because they were so far apart.
Two earthquakes rocked Myanmar on Thursday, occurring within
two hours in the remote northern Kachin state, about 1,440 km
north of the capital Yangon. There were no reports of casualties.
"We think the epicenter may be at a very sparsely populated
area," an official said.
About 26 minutes after Myanmar's first quake, China's
southwestern province of Yunnan felt a tremor measuring 7.3,
about 140 km north of the Myanmar town of Myitkyina.
An earthquake bureau official in the Yunnan district of Liuku
told Reuters many buildings in the area had been damaged,
although there were no immediate reports of casualties.
It was the second quake to hit China this week. On Tuesday, 24
people were injured in the northwest province of Gansu in a
tremor that measured 5.9.