Earthquake in Japan

Experts say Japan's tsunami warning system won a seemingly impossible race
against giant ocean waves, offering possible lessons to countries like India.
The Japan Meteorological Agency put out its first tsunami warning with details
of which prefectures were likely to face the most dangerous waves, a t 2.49pm just three minutes after the
quake on March 11.
A detailed warning, listing the height of waves likely to strike each
prefecture and the time of arrival of the tsunami at each place followed a
minute later - at 2.50pm.
The warnings were too late for Iwate prefecture, where the tsunami stuck
first at 2:49pm, but beat the waves to all other prefectures.
"...This is the best timing I have seen for a tsunami warning system, and is
an example for all of us," Sri Lankan tsunami expert Rohan Samarajiva said.

Japan's timing is significant for countries such as India and Sri Lanka
because the nearest fault-line in the Indian Ocean lies near the Andaman and
Nicobar Islands.
While Japan is forced to face tsunamis - generated just off its coast - India
has up to 120 minutes before a tele-tsunami (long-distance tsunami) hits the
Tamil Nadu coast.
Reducing the time needed for issuing warnings increases the time available
for evacuations, experts said. Indonesia took 14 minutes to issue warnings about
the 2004 tsunami off Sumatra.
The Indian National Centre for Ocean Information Services took eight minutes
to put out its first bulletin on the Japan quake last Friday. The key to the
Japanese success appears to lie in pre-analysed models that allowed a
fully-automated warning system to make near-immediate announcements, the experts
said.
"India's tsunami warning system is now much better than it was in 2004. But
there are things to learn from the Japanese..." IIT Kharagpur professor PK
Bhaskaran said.
The process of warnings involves sensors on the ocean bed picking up wave
signals, transmitting them to land stations, evaluating the wave height and time
before the tsunami hits land, and obtaining clearances for evacuation.