SYDNEY (Reuters) - The southern
Indian Ocean, where investigators suspect missing Malaysia Airlines
Flight MH370 may have come down, is one place where a commercial
airliner can crash without a ship spotting it, a radar plotting it or
even a satellite picking it up.
The
empty expanse of water is one of the most remote places in the world
and also one of the deepest, posing potentially enormous challenges for
the international search effort now refocusing on the area, one of
several possible crash sites.
Even
Australia, which has island territories in the Indian Ocean and sends
rescue planes to pluck stricken yachtsmen from the cold, mountainous
seas in the south from time to time, has no radar coverage much beyond
its Indian Ocean coast.
"In
most of Western Australia and almost all of the Indian Ocean, there is
almost no radar coverage," an Australian civil aviation authority source
said, requesting anonymity as he was not authorised to speak on the
record.
"If anything is more than 100 kilometres offshore, you don't see it."
So far, search operations by navies and aircraft from more than a dozen nations have failed to find even a trace of Flight MH370, which went missing a week ago after taking off from Kuala Lumpur for Beijing and diverting from its intended flight path.
The search effort has focused mainly on the South China Sea but is now switching to the Indian Ocean after investigators, having pieced together radar and satellite tracking data, began to suspect the Boeing 777-200ER had been deliberately flown hundreds or possibly thousands of miles off course.
Searchers still face a daunting array of possible last locations for the plane, including the northern end of the Indian Ocean as well as central Asia, though investigators say it is more likely to have flown to the south than through busier airspace to the north where it would likely have been detected.
With an estimated four hours fuel left when last spotted by radar off Malaysia's northwest coast, the plane could have flown a further 2,200 miles (3,500 km) or so, assuming normal cruising speed and altitude.
Officials think, based on
the available data, the aircraft flew south until it ran out of fuel and
crashed into the sea, according to a source familiar with data the U.S.
government is receiving from the investigation.
In the south, any debris from MH370 would have been widely dispersed by Indian Ocean currents in the week since it disappeared.
SCATTERING OF ISLANDS
The
southern Indian Ocean, between Indonesia and Australia, is broken up
only by the Australian territories of Christmas Island, home to asylum
seeker detention facilities, and the Cocos (Keeling) Islands some 2,000
km (1,240 miles) northwest of Perth. The Cocos Islands have a small
airport to serve the islands' combined population of just 3,000 people.
Further
south, the only habitation is the handful of research stations on the
scattering of tiny French-run islands including Kerguelen - a group of
volcanic outcrops between Africa, Australia and Antarctica. While home
to several powerful astronomical scanners and radar, there is no airport
and it is seen extremely unlikely the aircraft could have made it that
far.
The shipping route from
Western Australia north to Asia and Europe is considered relatively
quiet in global shipping terms, despite the large amount of iron ore and
other resources that are shipped from Australia's northwest ports.
Ships
track north staying close in to the West Australian coastline and then
head north through Indonesian waters into the South China Sea or
northwest toward the Red Sea.
Australia's
civil aviation radar extends a maximum of just 200 nautical miles (410
km) off the coast, the civil aviation authority source said, and was
used only for monitoring scheduled aircraft on approach into the country
and subsequent landings.
There
are just two primary radars on the west Australian coast, one in Perth
and one further north in Paraburdoo, which has even less range and is
used to monitor mining traffic heading to the nearby Pilbara region.
The
source said that this was the case with flights by Emirates Airlines,
which all fly over the Indian Ocean to Australia, but it did not provide
a specific radar plot.
Australia does not have any government satellites.
The
Australian military has an over-the-horizon radar network that allows
it to observe all air and sea activity north of Australia for up to
3,000 km (1,860 miles). This encompasses all of Java, Papua New Guinea
and the Solomon Islands.
While
the Jindalee Operational Radar Network (JORN) extends part-way across
the northern Indian Ocean, government papers online describe it as a
"tripwire" in Australia's northern surveillance system, helping underpin
the defense of the country from any attack originating from the north.
Local
media have said its main use recently has been to track illegal
immigrants approaching Australia by boat through the region's largely
unguarded northern waters.
The Australian Defence Force was not available for comment on Sunday.
A
potential crash site around 1,600 km (1,000 miles) northwest or west of
the Australian coast would be well within the search and rescue area of
the Australian Maritime Safety Authority (AMSA), one of the largest in
the world.
An AMSA spokesman said no request for assistance had been received from Malaysia as of Sunday.
Source: Yahoo News
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