填空题
You should spend about 20 minutes on Questions 28-40, which are based on
Reading Passage 3 below. [*]
Inadequate Warning System Left
Asia at
the Mercy of Tsunami
When two tectonic plates
beneath the Indian Ocean cracked past each other at 0.59 GMT on 26 December
2004, the sea floor was forced upwards by some 10 meters. This displaced in the
region of a trillion tonnes of water, driving it towards Southeast Asia's
coastline in a long, low amplitude wave traveling at up to 900 kilometers per
hour.
When the wave reached shallower water near the coast, it
shortened, slowed and gathered into surges that killed at least 150,000 people
across a dozen countries. In the aftermath of the disaster, casualties continue
to mount at a ferocious pace. Seismologists knew about the magnitude 9
earthquake within minutes, but the absence of monitoring equipment in the ocean
itself meant that they didn't know for sure that a tsunami had occurred. Those
who suspected as much were unsure how to get the word out to the regions most at
risk.
Although the small global community of tsunami researchers
had expressed some concerns about the risk of such an event, little had been
done to plan for it. "It is always on the agenda," says Vasily Titov, a tsunami
researcher at the Pacific Marine Environmental Laboratory in Seattle,
Washington. But he says that it has been difficult to raise the money for a
monitoring system. "Only two weeks ago it would have sounded crazy," he says.
"But it sounds very reasonable now. The millions of dollars needed would have
saved thousands and thousands of lives. "
The most recent
comparable event in the region took place in 1883. In contrast, earthquakes in
Chile in 1960 and Alaska in 1964 led to the creation of a reasonably
sophisticated tsunami warning system in the Pacific Ocean. Two international
tsunami warning bodies exist under United Nations Educational, Scientific,
and Cultural Organization (UNESCO)'s Intergovernmental Oceanographic
Commission (IOC). the International Coordination Group for the Tsunami Warning
System in the Pacific, known as ITSU, and the International Tsunami Information
Center based in Hawaii. They get by on annual budgets from the IOC of about US $
40,000 and $ 80,000, respectively, which are supplemented by grants from nations
on the Pacific rim.
To predict a tsunami with any useful time
advantage, researchers say, data on small changes in sea level and pressure have
to be collected directly from the floor and surface of the ocean. The strength
of the event depends on the displacement of the ocean floor, not on the strength
of the earthquake.
Some buoys that could provide such data are
already in place in the Indian Ocean. And only a few weeks before the tsunami
struck, members of ITSU were talking about how these could be adapted for use in
a tsunami-warning system, says Peter Pissierssens, head of ocean services at the
IOC.
Within 20 minutes of the earthquake, at least three
monitoring stations in the United States had detected it, initially estimating
its magnitude to be around 8. The United States Geological Survey (USGS)
circulated the information to about 100 people, mostly its own researchers and
senior officials, within 16 minutes, and sent a more detailed bulletin to a list
of external contacts, including the US Department of State, after an hour. The
USGS has no responsibility for tsunami monitoring and its statement did not
mention the risk of such an event.
The Hawaii-based Pacific
Tsunami Warning Center (PTWC), meanwhile, sent out a bulletin to its regular
circulation list, noting that the event presented no tsunami risk in the
Pacific. According to Laura Kong, director of the International Tsunami
Information Center, "let's keep an eye on it" was the prevalent attitude that
night. "At that point, none of us expected anything like what we have seen,"
says Charles McCrery, director of the PTWC and deputy chair of ITSU. "We
expected a local tsunami at most. "
At 2:04 GMT, the PTWC put
out another bulletin revising the quake up to magnitude 8.5. Because there was
no information about sea levels in the area, the existence of a tsunami was
merely hypothetical, but staff were worried enough to begin looking for numbers
to call in Asia.
According to Kong, the team tried and failed to
reach colleagues in Indonesia. Australia was contacted, although to little
avail, as that country experienced only half-metre waves. It was not until 3.30
that the team in Hawaii saw news reports on the Internet of casualties in Sri
Lanka. The wave had already crossed the ocean, to devastating effect.
Kong says that without a predetermined communication plan, warning efforts
were doomed from the start. But she adds that the PTWC will in future directly
contact the US state department, which can communicate risks to any nation, at
any time.
Indonesian seismologists initially underestimated the
strength of the earthquake, according to local news reports. And although
officials there had very little time in which to act, an instrument that could
have helped warn them of the approaching wave was transmitting its information
to a dead phone line, according to a senior Indonesian seismologist.
Efforts over the years to get an Indian Ocean warning system in place have
made little progress in the face of national governments' reluctance to invest
in them. In 2003, a working group on the Tsunami Warning System in the Southwest
Pacific and Indian Ocean was established within ITSU. But Pissierssens says that
the first chair of the group, a representative from Indonesia, left soon after
his appointment and that the group then split into two according to
region.
Phil Cummins a seismologist at Geoscience Australia in
Canberra agreed to write a position paper for the group on tsunami risk in the
Indian Ocean. "1 am still in the process of writing that paper," he says. "No
one else was 100% convinced that we should worry and that included me, I've got
to admit. "
According to Pissierssens, UNESCO will now make an
observation system in the Indian Ocean a priority. "The first thing we will do
is send out a survey team in January or February," he says, "and then we want to
set up a conference in the area." Needless to say, there is little reluctance
now to accept the need for the system. The UN International Strategy for
Disaster Reduction has also said that one should be built within a year. And the
Indian government, under intense domestic pressure for its failure to warn
people on its eastern coast, said it would spend up to US $ 29 million to build
a system itself (see 'India pledges to fund alert system in wake of disaster',
above).
Nicole Rencoret, spokeswoman for the UN's
disaster-reduction branch, notes that early warning systems could watch for
other natural disaster risks, as well as tsunamis. "There has been an enormous
amount of focus on tsunamis, but we need to take a multihazard approach," she
says.
Questions 28-33
Do the following statements agree with the information given in
Reading Passage 3 ?
In boxes 28-33 on your answer sheet,
write
TRUE
if the statement agrees with the information
FALSE if the statement
contradicts the information
NOT GIVEN
if there is no information on this