The chance to escape is probably slim when, or if, a big earthquake happens. But let’s live with this reality: Those giant tectonic plates are highly active underneath Indonesia. We may take earthquakes for granted while scientists warn monstrous ones may be yet to come.

That is a risk that comes with living in a country located on the Pacific “ring of fire”. Indonesia lies on top of two major tectonic plates — the Eurasia and Indo-Australian plates — as well as several minor ones. The country is also surrounded by the Pacific and Philippine Sea oceanic plates.

An earthquake occurs whenever these plates hit each other, or the immense energy accumulated from years of contact between two plates is released.

Indonesia has recorded numerous massive earthquakes and resulting tsunamis over the past few centuries. In 1699, a big earthquake destroyed much of what is now Jakarta. In 2004, the well-documented natural catastrophe in the Indian Ocean left 170,000 dead in Aceh. Just two months ago, on Sept. 28, a 7.0-magnitude earthquake and tsunami struck Central Sulawesi, leaving more than 2,000 people dead and a massive trail of destruction. That happened only two months after a 6.4-magnitude quake wrought devastation in Lombok, West Nusa Tenggara, which claimed more than 500 lives and left thousands of families homeless.

The latest string of earthquakes sent a chill on other islands. Scientists warn of similar disasters in Java, where about 150 million people live, or close to 70 percent of Indonesia’s population. On this island, the latest major earthquake struck the West Java regencies of Tasikmalaya and Cianjur, where the death toll reached 87 in 2009.

In Java, and probably parts of Sumatra, it is believed that the biggest threat will come from the Sunda megathrust located deep beneath the sea, around 150 kilometers south of Java. It is where the edges of two tectonic plates converge.

Earthquakes can happen in megathrust zones when one plate forces the other underneath in a process called subduction. The subduction zone between the Eurasian and Indo-Australian plates is called the Sunda megathrust, which stretches in the Indian Ocean from Sumatra west to Java south.

While most megathrust earthquakes are small with a moment magnitude scale (M) under 5, the effect can be immense. Experts say that the 2004 quake triggering deadly tsunamis in Aceh and several other countries by the Indian Ocean was a megathrust that happened when part of the Indo-Australian plate was subducted by the Eurasian plate.

It is feared that a similar disaster may occur in Java if the Sunda megathrust releases energy to the surface big enough to trigger a tsunami.

However, scientists have discovered that several smaller tectonic faults are also able to trigger large-scale earthquakes in the island’s west coast.

The most well-known might be the Lembang fault in West Java which, scientists say, moves at a speed of 3 millimeters a year, a bit slower than the Palu-Koro fault in Sulawesi that triggered the September earthquake.

While it does not pass under the West Java provincial capital of Bandung, a large earthquake triggered by the Lembang fault is predicted to still cause massive destruction.

Then, there is also the Baribis fault, stretching from East to West Java. It is believed to have caused a 7-plus-magnitude earthquake in Jakarta in 1780.

“Unfortunately, we know very little about this fault, especially its precise location in western Java — whether it passes under Bogor, Jakarta or in between,” says Sukmandaru Prihatmoko, chairman of the Indonesian Geologists Association (IAGI).

Despite the well-known potential dangers from earthquakes, geological information that Indonesia needs for mitigation purposes, especially in major cities like Bandung and Jakarta, is far from adequate.

Ironically, public information drives sometimes hit a snag largely because of a lack of understanding among laypeople and authorities alike about how science works. The best-known case in point occurred in April when Widjo Kongko, a scientist from the Agency for the Assessment and Application of the Technology (BPPT), was summoned by the police on suspicion of spreading false information after he made public his study about the Sunda megathrust.

His most earth-shaking revelation during a seminar on potential big quakes in Java was that a 9.0-magnitude Sunda megathrust could unleash a tsunami as tall as 57 meters and could sweep through western Java down to its northern coasts, including Jakarta.

The findings sparked a heated debate in the local media. The Meteorology, Climatology and Geophysics Agency (BMKG) was among those skeptical about his theory and police believed it was dangerous. Widjo eventually escaped scrutiny after civil groups and fellow academics came to his defense.

The Central Sulawesi disaster has been a wake-up call for the need for information on potential major earthquakes in the future. The National Disaster Mitigation Agency (BNPB) has issued a disaster mitigation handbook on safety measures.

“We need to educate people on disaster mitigation because their awareness [on the issue] is poor,” says BNPB spokesman Sutopo Purwo Nugroho.

Popular

Volcano erupts in North Sulawesi, hundreds evacuated

Dubai roads, airport reel from floods after record rains

Ramadan boosts consumer confidence, retail sales