Indonesia world's most earthquake-prone country

Indonesia world's most earthquake-prone country

By William Furney

JAKARTA (JP): Every day, some 20 earthquakes rock various
parts of Indonesia, leading to a total of about 7,000
subterranean movements each year. Of that number, only about 60
are felt. Among those, however, are what are known as killer
quakes -- earthquakes whose magnitude is great enough to destroy
buildings, roads and lives.

Such was the case on June 4 this year when a quake measuring
7.3 on the Richter scale flattened much of the town of Bengkulu
in the southwestern tip of Sumatra island.

The unrelenting forces of nature are harsh in this tropical
country, with lives persistently being ruined by natural
disasters such as volcanoes, mudslides and earthquakes, Indonesia
having more of the latter than any other country on earth. The
Bengkulu quake killed 90 people, seriously injured 803 and left
another 1,782 others slightly injured. The quake damaged 30,374
houses, 513 places of worship and destroyed roads in 26
locations. Prosaic though they may be, powerful large-magnitude
earthquakes are not something that can be foreseen and when they
occur they do so with little regard for human life.

Sri Diharto is used to being woken in the early hours of the
morning. After four years as head of the Meteorological and
Geophysics Agency (BMG) of the Department of Communications, he
is adept at fielding enquiries from jittery journalists. "They
want to know everything at once, where the epicenter was and the
scale of the quake. They should be more patient," he said in an
interview with The Jakarta Post.

But the frustrations of waiting journalists as they edge
toward their deadlines and those of his own office are now the
stuff of yesteryear, belonging in a small room in the agency's
office that houses ancient seismographs from the Dutch era. For,
it now has enough leading edge imported technology to make the
mouths of the most ardent earthquake trackers salivate. A
"Supercomputer Room", chilled by strong air-conditioners awaits
the arrival "soon", through a soft loan, of an estimated US$19.5
million terabyte cruncher.

Vice President Megawati Soekarnoputri was due to open the
newly renovated facility last month, but due to ongoing political
snafus, the opening has been postponed until later in the month.

The new facility encompasses BMG's Communications and Computer
Center, Weather and Climate Center, National Earthquake Center
and the agency's Air Quality Center.

Operating 24 hours a day and with a total workforce of 3,500,
750 of whom are based at the Jakarta headquarters, BMG is
responsible for disseminating information about earthquakes when
they occur. Not only to the public and media, but also the
National Disaster Management Coordination Board and related
government departments so they can send relief or rescue teams.

Said Sri Diharto: "When a quake happens we need at least 15
minutes to determine where the epicenter was. But then we have
people on the phone wanting immediate answers and we have to make
an estimation. Sometimes, the estimations are wrong, as with the
Sukabumi quake. We said the epicenter was in Pandeglang, when
later we determined that it had been in Sukabumi."

Unpredictable

Even with its new and sophisticated technology, BMG, like
other agencies around the world, cannot predict when a quake will
occur. But there are certain areas in the country that are more
prone than others. West Sumatra, along the Indian Ocean down to
the Sunda Strait; the south of West Java around the Sukabumi area
which is traversed by the Cimandiri fault; the Nusa Tenggara
area; the Maluku islands; and Sulawesi are earthquake hot zones.
Also Irian Jaya, which has many local faults and is very prone to
earthquakes. The Indoaustralia plate meets with the Euroasia and
Pacific plates, and their movements cause intense tectonic
activity in Indonesia. Because of the pressure, the Indoaustralia
plate moves 7 cm to 12 cm per year. Along of the coast of Sumatra
is the most earthquake-prone area, while Kalimantan is virtually
quake-free.

Earthquakes are caused by tectonic movements, the shifting of
plates in the Earth's crust. If a quake happens on land, like the
recent 5.1 magnitude Sukabumi quake, it will be felt and the
effects are often devastating. But if an earthquake happens on
the sea floor, even with those of large magnitude, the effects
are limited and in many cases tremors will not be noticed. The
danger of earthquakes under the sea, however, is that they are
often followed by tsunami, giant waves caused by the submarine
earth movements.

Earthquakes are measured on the Richter scale, which
determines the magnitude at the center of a quake while the
Modified Mercalli Indicator is what is felt, depending on the
distance from the epicenter.

The Bengkulu quake was the most severe over the past few
years. The last high-scale earthquake in Bengkulu was in 1833,
and there were resulting tsunami.

In the past, houses were made from wood and bamboo but
concrete has long been the material of choice and is naturally
heavier and not so pliable. The Ministry of Public Works,
however, issues guidelines to builders about the construction of
buildings in quake-prone areas.

In terms of monitoring the country, BMG divides Indonesia into
five regions: Medan, North Sumatra; Jakarta, Java; Denpasar,
Bali; Makassar, Sulawesi; and Jayapura, Irian Jaya. Monitoring
stations in each of these regions use Indonesia's Palapa
satellite to relay real-time information back to BMG
headquarters.

As with any period of uncertainty, be it during power outages,
volcanic eruptions or earthquakes, the public reach for the phone
to call relevant officials for information. Up to now, this has
been a problem for the agency, as there is a limited number of
telephone lines. BMG, however, has just established a new
information service.

"Every time there is a quake, the telephone lines are jammed.
To counter this, I've installed a new telephone system which will
have all the information about new earthquakes. It'll make our
office more efficient. This facility is available to the public,"
said Sri Diharto.

Recent reports have been saying that with the increasing
number of quakes in the capital, Jakarta can expect a sizable
earthquake. Sri Diharto, however, refutes this.

"It depends on the scientific approach. People have their own
ideas, and whatever the newspapers say becomes the news. We are
an official agency and can only tell the public what has
happened. If we look back over the last 100 years, there have
been no severe earthquakes in Jakarta.

"There have been numerous quakes in Jakarta over the last few
months but none of the many high-rise buildings in the capital
have collapsed. Even small magnitude quakes could cause them to
fall down if they were not built correctly and according to
procedures. We've seen some damage in some of the older buildings
though, such as City Hall, which developed cracks after a quake
in 1996."

Seismologist and head of the National Earthquake Center, based
at BMG headquarters, Suhardjono says the Indoaustralia plate,
which Jakarta sits on, is getting deeper each year, meaning the
likelihood of a strong earthquake in the capital is remote.

But when earthquakes do occur, he said, people should "get out
of the house, if they can. But earthquakes happen so quickly and
only last a short time. Therefore, if you live in a high-rise
building, you should know your surroundings so that you can get
under the nearest table or chair. These are the safe things to
do. It's not always advisable to stand under a door frame because
sometimes it's not strong enough and can collapse."

Suhardjono said people living in high-rise buildings should
hold drills twice a year so that they would know what to do in
the event of a quake.

"Outside, you've got to watch the ground, because it sometimes
opens up. Going to a beach is not a good idea as sometimes the
water recedes and there are lots of fish stranded. People go and
collect them and are drowned when the sea quickly comes back in.
This is what happened a long time ago in France."

After the tremors, houses should be inspected for cracks, he
said.

-- BMG's earthquake information hotline numbers are 654-6316
and 420-9103.