Remembering Tsunami 2004: Will we be warned in time if the next big tsunami hits?

The Star, 22 Dec 2014

On the 10th anniversary of one of Asia’s worst natural disasters, the Boxing Day tsunami of 2004, MetMalaysia briefs us on what tech we have in place to guard people living along the country’s shorelines.

MALAYSIA’S preparedness in dealing with a future tsunami lies in an early warning system that spans data collection, processing and dissemination through a network of sirens that has been installed at identified hotspots nationwide.

At the Early Warning Tsunami Section, set up within the Earthquake and Tsunami National Centre of the Malaysian Meteorological Department, multiple screens display images of coastlines relayed from closed-circuit television (CCTV) cameras that have been put up on strategic hotel fronts and at vulnerable beaches. Seventeen CCTVs are in place in the north of Peninsular Malaysia. The feeds are monitored for the onset of threatening waves around the clock and in real time by staff on shifts in the section, which is located in Petaling Jaya.

Staff members also observe a host of other monitors that track unusual or abnormal wave-forms that could be the result of seismic activity; these are connected to 44 seismic stations that have been established nationwide – 32 in Peninsular Malaysia and 12 in Sabah and Sarawak.

“All data are transmitted in real time through satellite communication and broadband lines to our national centre here (in Petaling Jaya) for processing and dissemination,” explains Dr Mohd Rosaidi Che Abas, the Malaysian Meteorological Department’s deputy director-general (strategic and technical).

There are data streams from regional and international sources to monitor, too. As with most tsunami detection centres in this region, the Malaysian section is hooked into the US National Oceanic and Atmospheric Administration’s Pacific Tsunami Warning Centre (PTWC) in Hawaii and the Japan Meteorological Agency in Tokyo.

Malaysia’s system also receives live information from deep sea buoys; while we maintain only one deep sea buoy, off the coast of Layang-Layang Island, we receive data from Indonesia, which has more buoys.

There is also a tide gauge network installed in several locations, including Porto Malai (on Pulau Langkawi), Pulau Perak and Teluk Bahang in the north of Peninsular Malaysia; Pulau Perhentian off the north-west coast of Peninsular Malaysia; and also coastal regions such as Kudat and Lahad Datu in Sabah. Data is also received from international and regional tide gauge networks such as the GLOSS (Global Sea Level Observing System) and the Indian Ocean network.

Some of the data are used to generate simulation analyses through computer modelling exercises to provide estimates on what conditions would trigger a tsunami, and if so, the projected locations where the waves would hit, and the predicted time of their arrival.

When the information from all these sources point towards a possible tsunami, the warning system comes into play, explains Dr Mohd Rosaidi.

There are currently 23 sirens in the country, that were established at a cost of RM2.7mil: 14 on the peninsula (stretching from Perlis down to Selangor, and from Terengganu to Pahang), eight in Sabah, and one in Sarawak, with plans to add another 31 at a cost of about RM3mil (US$921,000).

The siren system comprises a 16m-high pole with a loudspeaker at its top that can blare out sounds that can be heard up to 3km in-shore (when wind conditions are normal and there aren’t any blindspot obstructions).

“The sirens are checked every three months to ensure they are in proper working condition. For the additional 31, they will greatly help beef up the existing spots,” says Dr Mohd Rosaidi.

Either a tsunami alert or tsunami warning will be issued from the sirens. The alert is a precautionary measure that directs people to move away from the beach or river mouth, while a tsunami warning is far more serious, indicating that a tsunami is approaching and not only people on beaches and by river mouths but also people living in high-risk areas will have to evacuate immediately to safer spots.

Dr Mohd Rosaidi explains that the centre has also come up with four possible “worst case scenarios” of tsunamis that could strike Malaysia from the Andaman Sea, Sulu Sea, South China Sea, and Sulawesi Sea.

By producing data and a correlating timeline of an impending tsunami disaster if strong earthquakes were to occur in the beds of these four seas, the centre calculated how high waves could get and how fast they would hit local shores:

> Assuming (through a historical census) that a 9.5 magnitude earthquake occurs in the Andaman Sea bed, the highest wave would hit Kuala Perlis within an hour and 51 minutes.

> A 9.0 magnitude quake in the Sulu Sea bed would cause Sandakan in Sabah to be hit by a 15.9m-high wave in two hours and 22 minutes after the quake.

> A 9.0 magnitute quake in the South China Sea bed will push a 5.6m-high wave towards Sabah and Sarawak; and on the Peninsula, Kelantan, Terengganu and Pahang, will be affected. Kota Kinabalu will experience the highest wave at 5.6m in two hours and 20 minutes. This scenario is worrying, says Dr Mohd Rosaidi, because scientists have predicted that it will involve the Manila Trench – and that it is already long overdue.

> A 9.0 magnitude earthquake in the Sulawesi Sea bed is a particularly worrying scenario according to Dr Mohd Rosaidi. A first wave of 26m would crash into Tawau, Sabah, within 40 minutes; a wave of 28.9m will hit Semporna, also in Sabah, within 49 minutes – this means coastal communities in these areas have only between 30 and 40 minutes to evacuate.

“We conduct awareness programmes and tsunami drills as regularly as possible for these populations; the last we had was a few months ago in Kuala Terengganu with an upcoming exercise in Sabah.

“The different agencies like the police and fire department too have standard operating procedures to follow in the event of such disasters.

“We have also the Fixed Line Alert System to disseminate warnings and information to homes located up to 3km from the beach.”

This scheme was worked out between the agency and Telekom Malaysia in 2005: voice messages will be transmitted to designated fixed phone lines within 10 minutes of a warning siren sounding. Once the need for evacuation arises, the phones will continue ringing until they are picked up.

Although the Early Warning Tsunami Section installs and manages all the technology, from the sirens to the seismic stations, Dr Mohd Rosaidi says the sirens can only be activated (for emergency evacuations) after the green light is received from the National Security Council, which has to first seek approval from the Prime Minister. The National Security Council is the principal body in the country coordinating all disaster management networks and their related operations.

MetMalaysia (www.met.gov.my), as the meteorological department is called, comes under the aegis of Mosti, the Ministry of Science, Technology and Innovation.

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