Singapore at risk if lesser-known undersea volcanoes in region erupt

Researchers cite tsunami waves, tech outages as possible impacts

- Shabana Begum

It has long been assumed that Singapore is sheltered from volcanic eruptions and tsunamis, but new research into 466 lesser-known undersea volcanoes in the region shows that the island state is not immune to rare, explosive events.

If a large, slumbering underwater volcano in the South China Sea were to erupt, it can set off tsunami waves that could reach Singapore’s coastlines.

Volcanic ash can blow towards Singapore, blanketing the surface with fine ash, similar to an eruption of a land-based volcano. When the Philippines’ Mount Pinatubo erupted in 1991, a layer of ash covered the ground, cars and even the floors of houses across Singapore.

Lava flows and volcanic rock avalanches can damage undersea cables in the region, causing internet outages and disrupting financial transactions.

“Singapore can be affected too because these cables are thousands of kilometres long, and Singapore has some of the main subsea cables and landing sites in South-east Asia,” said Dr Andrea Verolino, a research fellow at NTU’s Earth Observatory of Singapore (EOS).

The 2022 Hunga Tonga-Hunga Ha’apai mega eruption, which was hundreds of times more powerful than the Hiroshima atomic bomb, got Dr Verolino thinking about what could happen if a similar disaster happens in the region.

The explosion from the South Pacific Ocean seamount triggered far-reaching tsunamis that struck the shores of Japan, Peru, Chile and Russia. Tsunamis that swept onto Tongan islands reached as high as 20m, displacing more than 1,500 people and causing four deaths.

In Peru, freak waves caused an oil spill from a tanker ship.

Dr Verolino and his colleagues mapped out 466 submerged seamounts and volcanic islands in the waters of South-east Asia, Taiwan, and the Andaman and Nicobar Islands – with the help of published data sets and sea-floor topography information. Hundreds of them are ancient giants lurking in the deep, mostly overlooked and forgotten.