RUN LIKE THE WIND
Dec 29th 2004

How to avoid dying in a tsunami

ONE pertinent question in the wake of the earthquake near Aceh and the
tsunami it generated is how much notice of an approaching wave can be
given to vulnerable people without the risk of crying "wolf" too often.
Earthquakes themselves are unpredictable, and likely to remain so. But
detecting them when they happen is a routine technology. That was not
the problem in this case, which was observed by monitoring stations all
over the world. Unfortunately for the forecasters, although any
powerful submarine earthquake brings the risk of a dangerous tsunami,
not all such earthquakes actually result in a big wave, and false
alarms cost money and breed cynicism.

On top of that, most "tsunamigenic" earthquakes, which are caused when
the processes of plate tectonics force heavy, oceanic crustal rock
below lighter, continental rock to create a deep trench at the bottom
of the sea, occur in the Pacific, which is almost surrounded by such
trenches. In the Indian Ocean, deep trenches are confined to the
southern coast of Indonesia, and tsunamis are rare. Since most of the
countries affected by this tsunami are poor, or middle-income at best,
and monitoring costs money, this might suggest that a fatalistic
approach to the question is reasonable. But American and Japanese
experience suggests that effective monitoring need not be that
expensive.

These two countries have networks of seabed pressure-detectors that can
monitor tsunamis and indicate whether and where evacuation is
necessary--data they share with their Pacific neighbours. A system of
seven detectors, run from Hawaii, cost about $18m to develop, and the
experience gained doing so means a similar system might now be had for
as little as $2m. So, to the sound of stable doors being bolted firmly
shut, politicians in South-East Asia and Australia are proposing one
for the Indian Ocean.

Detecting tsunamis directly, rather than relying on earthquake
monitors, is important for another reason, too. Not all tsunamis are
caused by earthquakes. Some of the worst, such as a 15-metre-high
monster that killed more than 2,000 people in New Guinea in 1998, are
the result of submarine landslides (though these can themselves be
triggered by earthquakes, as was the case in New Guinea). Indeed, a few
years ago it was suggested that a landslide in an unstable part of La
Palma, one of the Canary Islands, might cause a tsunami that would
devastate the east coast of America.

Even if you have an effective detection system, though, it is useless
if you cannot evacuate a threatened area. Here, speed is of the
essence. Computer modelling can help show which areas are likely to be
safest, but common sense is often the best guide--run like the wind,
away from the sea. Evacuation warnings, too, should be easy to give as
long as people are awake. Radios are ubiquitous, even in most poor
places. It is just a matter of having systems in place to tell the
radio stations to tell people to run. The problem was that no one did.

 

See this article with graphics and related items

 

ASIA'S DEVASTATION
Dec 29th 2004

Reflections on a rare but terrible calamity

THE clue lies in the Japanese name that has been adopted for them
around the world: TSUNAMI. Formed from the characters for harbour and
wave, and commemorated in the 19th-century woodblock print by Hokusai
that decorates so many books and articles about the subject (see
article[1]), the word shows that these sudden, devastating waves have
mainly in the past occurred in the Pacific Ocean, ringed as it is by
volcanoes and earthquake zones. Thanks to one tsunami in 1946 that
killed 165 people, mainly in Hawaii, the countries around the Pacific
have shared a tsunami warning centre ever since. Those around the
Indian Ocean have no such centre, being lucky enough not to have
suffered many big tsunamis before and unlucky enough not to count the
world's two biggest and most technologically advanced economies, the
United States and Japan, among their number.

So when, on December 26th, the world's strongest earthquake in 40 years
shook the region, with its epicentre under the sea near the
northernmost tip of the Indonesian archipelago, there was no
established mechanism to pass warnings to the countries around the
ocean's shores. There would have been between 90 and 150 minutes in
which to broadcast warnings by radio, television and loudspeaker in the
areas most affected, the Indonesian province of Aceh, Sri Lanka and the
Indian chain of the Andaman and Nicobar islands. Had such warnings been
broadcast then many of the tens of thousands of lives lost would have
been saved. How many, nobody can know, for the task of evacuation would
have been far from easy in many of these crowded, poor and low-lying
coastal communities. Equally, though, it will probably never be known
exactly how many people have died (see article[2]). Whereas in many
disasters the initial estimates of fatalities prove too high, the
opposite is occurring in this case.

MAKING A VIRTUE OUT OF DISASTER
The question of whether there should now be some sort of seismic and
even tsunami warning system established for the Indian Ocean is not
currently the most urgent one, however. After all, big tsunamis are
thankfully extremely rare occurrences. There is no reason in science to
believe that they are becoming any more likely. The most urgent
questions concern how much humanitarian aid can be mustered by the
world's richer countries and how it can be distributed.

The Indian Ocean tsunami has been called the world's worst ever natural
disaster. In terms of cold statistics, that is wrong, even as the
estimated death toll climbs well past 50,000. Other earthquakes have
killed more, especially in poor and populous countries such as China:
probably 600,000 or more in Tangshan in 1976, and 200,000 or so on two
occasions in the 1920s. Iran lost an estimated 50,000 people to a quake
in 1990 and a further 26,000 in Bam exactly a year ago to the day, on
December 26th 2003. It is not even the Indian Ocean's deadliest
disaster, for cyclones have often brought worse, most notoriously in
1970 when the then new state of Bangladesh lost about 500,000 people.

What is special about this tsunami is the geographical extent of the
devastation and the number of countries affected. Earthquakes produce
terrible consequences, but normally of a highly localised sort. This
time, particularly in Sri Lanka, Indonesia, India and Thailand, the
damage stretches across thousands of miles and involves millions of
people. That produces a huge logistical challenge for international
organisations and aid agencies: how to get relief supplies and, later,
reconstruction assistance to so many places at more or less the same
time. Much more of the money and planning will have to be devoted to
planes, helicopters, trucks and supply lines than in "normal" disasters
and relief efforts.

But let not everything about this terrible event feel bad. For in that
very geographical challenge lies also an opportunity, one that comes in
three main forms. The first is that the involvement in the disaster of
so many resorts favoured by tourists from rich countries in the West
and the richer parts of north-east Asia has given it even more
prominence in those countries than the sheer horror of the fatalities
would have produced. Such selfish distortions are regrettable in
theory--who noticed while millions were dying in Congo's wars?--but in
practice they might as well be exploited. It ought to be possible to
raise far more in charitable donations from individuals and
organisations in rich countries for relieving this disaster than for
single-country earthquakes or floods, for example.

The second is that the countries around the Indian Ocean itself
should, on this occasion, feel motivated enough to assist each other,
poor though all of them are, and to accept each other's help. Those
that were less affected and those on neighbouring seas, including the
Arab countries and around the Pacific, must surely be persuadable that
they too could easily have been affected by such an act of God,
whichever God it may be considered to have been.

That sense of mutual vulnerability brings us back to the question of
warning systems and to the third way in which this disaster could be
turned into an opportunity. Money and complacency are two reasons why
no tsunami warning system exists for the Indian Ocean. But the region
also suffers from a political fear of co-operation. Suspicions and
mistrust between many of the countries bordering the ocean, and between
those in the seismically turbulent region beyond, in Pakistan,
Afghanistan, Iran and elsewhere, mean that habits of cross-border
co-operation are weak. Even the exchange of seismic data is meagre, to
say the least, let alone interchange on more politically and
economically charged topics.

In 1999, when Greece and Turkey both suffered earthquakes in rapid
succession, the urge to assist each other led to a considerable thaw in
long-frosty relations. To build a warning system, including processes
to share seismic data and to pass on alerts expeditiously, would not be
an expensive operation. Nor would it prevent natural disasters in the
future, such is the power and unpredictability of nature. But it could
be a useful, non-controversial contribution to the easing of old
political tensions--and to saving some lives.

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[1] http://www.economist.com/displayStory.cfm?story_ID=3521075
[2] http://www.economist.com/displayStory.cfm?story_ID=3521017

 

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