Various:
Two earthquakes caused devastation across the Pacific earlier
this week. One, based off the coast of Samoa caused a tsunami;
the other, near Sumatra, was so deep that no tsunami occurred,
but the loss of life on the surrounding area may be
greater."The chances of there being a connection between these
two earthquakes is extremely slim," said University of Ulster
geophysicist John McCloskey,
told
the
London Times
. The 10,000 km distance between the
quakes and the orientation of the tectonic plates made a causal
link physically implausible, he said."The real danger in the
coming days is that a second larger quake with a magnitude of
around 8.5 could occur just off the coast of Padang," Professor
McCloskey said. That could result in a huge tsunami submerging
the town and surrounding coastline, which has a population of
about 1.5 million.A magnitude 6.6 event off the coast of
Sumatra
happened
earlier today.
The tsunami earthquakeThe tsunami that
devastated the islands of Samoa, American Samoa, and Tonga was
the result of a shallow rupture in the earth's crust on one of
the most geologically active areas of the world—where the
Pacific plate is plunging westward under the Australia plate at
a rate of 86 mm a year.The earthquake, which was measured as
high as 8.3 on the Richter scale, occurred 190 kilometers
southwest of American Samoa. The event caused one side of the
fault line to push up several meters higher than the other
side, according to initial estimates.Gary Gibson, a senior
seismologist at Environmental Systems and Services in
Melbourne,
told
Australia's ABC network that the energy released in the
earthquake was approximately one-thirtieth the size of the
Boxing Day 2004 earthquake near the island of Sumatra,
Indonesia.Gibson also
mentioned
to the
Sydney Morning Herald
that this earthquake was
unusual in that it was due to a north-east to south-west
tension in the crust. "The earth [was] being stretched rather
than compressed," he said.After the earthquake, the
Pacific
Tsunami Warning Centre issued a tsunami warning for South
Pacific nations, including New Zealand, which experienced a
rise in sea level of 40 cm, but Samoa, American Samoa and Tonga
were too close to the initial event to get enough
warning."People who live in areas where tsunamis can occur are
generally educated about them,"
said
John Bellini, a geophysicist with the National Earthquake
Information Center in Denver, Colorado. "If you feel an
earthquake, get to high ground as fast as you can." In this
case, he adds, "Five minutes was not enough time for emergency
services to move into action."Analysis of the data
indicated
that Hawaii was too far away for any major tide rise to
occur.
Related Links
Map
of the two earthquakes
Sumatra
and Samoa earthquakes were inside the 'Ring of Fire' fault
lines London Times
Samoan
tsunami caused by 'shallow quake'
When
two plates collide: rupture set off wave Sydney Morning
Herald
Tsunami
forecasts quicker, more accurate Honolulu Advertiser
Tsunami
warning system unable to help Samoans Inside Science
