Wednesday, December 8

Earthquake risk in Malaysia: A myth or an underrated truth?

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IT was Dec 26, 2004, a day after Christmas. I was an undergraduate at University of Malaya, staying in an apartment on the 17th floor. That morning, I felt dizzy. I observed the slow sloshing of water in my glass, which I had put on the table. I raised my head and saw a swaying KLCC Twin Towers. I saw occupants, mainly foreigners, running down and gathering in the open space car park downstairs. Being inexperienced and ignorant, it took me a while to realise it was an earthquake.

The news came an hour later. A magnitude-9.1 mega earthquake had struck the offshore subduction fault of Sumatera, about 600km away from Kuala Lumpur, which caused the Indian Ocean tsunami in 2004. If it had not been for Sumatra island taking the hit, sheltering the peninsula, the casualties in Sumatra would probably have been in the peninsula.

That was my, and perhaps also for many Malaysians in the peninsular, first experience of an earthquake. Some may argue that Sabahans experienced earthquakes in Lahad Datu and Ranau. I agree and will make use of this column to discuss that later. In fact, Sarawak too has experienced local earthquakes. Surprised?

Through my mentor, the late MC Hee, I joined the Earthquake Committee of Institution of Engineers Malaysia in 2010, which was assigned by the Department of Standards Malaysia to draft the first earthquake design standards. The code drafting process took eight years, marked by the publication of the Malaysian National Annex of Eurocode 8 in late 2017.

I find it interesting to share this experience of drafting a new design code for Malaysia, where the nation had not considered seismic actions at all in the past. Prof Nelson Lam from the University of Melbourne and I, being members of the committee, have collected some of the common beliefs, doubts, opinions, and fallacious arguments from various stakeholders – only two of which are discussed here: “There is no earthquake in Malaysia, do not make a mountain out of molehill!”, and “Properties will be very expensive if earthquake design is considered, why bother if the risk is low?”

The first argument of no occurrence of earthquakes in Malaysia is the easiest to rebut. Some of the earthquake incidences in Peninsular Malaysia were shared in the beginning of this article, the risk is known from long-distance Sumatran earthquake sources and the sporadic local earthquakes that can hardly be gauged.

For Sabah, it is a known risk, evidently after the 2015 magnitude-6 Ranau earthquake and perhaps the forgotten 1976 magnitude-6.2 Lahad Datu earthquake. For Sarawak, historically some magnitude-5 earthquakes have taken place near Tubau and Miri. Let’s not forget that the rest of the connected lands in Borneo (Kalimantan) have recorded some magnitude-5 earthquake events.

For a stable plate like Malaysia, being away from the Ring of Fire, does give people a false sense that either there are no earthquakes, or the earthquake risk is so low to the point of being negligible. In Australia, which is tectonically similar to Malaysia, there is on average one potentially destructive earthquake event occurring every year somewhere within the continent. The reason of not seeing earthquakes occurring locally in Malaysia at such a rate is simply because of the much smaller landmass. The underlying rate of activity between the two places may well be of the same order.

The second argument is on the price of property. I personally think that this is the most fallacious argument. Many, if not all, who uttered such spurious claims have business-related interests. The real costs of an earthquake are post-earthquake casualties, costs of repair, and business disruptions, and not the costs of design and construction. This logic is often flipped when communicating cost implications to clients and stakeholders in order to avoid the need of any engineering upskilling.

I would like to urge for the following. For code drafters, a state-of-the-art earthquake engineering philosophy is essential, particularly for low- to moderate-seismicity areas. It is overkill to directly adopt the methods used in high-seismic areas.

For policymakers, earthquake risk is always a socioeconomic-political decision and, hence, consensus needs to be achieved. For lawmakers, mandating seismic design for buildings can only be done through law enforcement, otherwise no one will adhere to the code of practice.

For design engineers, they need to jump out of their comfort zone of designing to gravity and wind actions only. Central to seismic design philosophy of buildings is to design buildings to have adequate energy dissipation characteristics without experiencing collapse. We are not designing a structure that is earthquake-proof, which is costly and often unachievable.

For other stakeholders, a point to ponder is that raising the safety level of buildings but expecting there to be no initial cost increase at all appears to be naive thinking. Remember, the real cost is about casualties, repair, and the downtime of the building.

The discussion above is to provide the proof that earthquake risk in Malaysia is not a myth. One may ask, if seismic risk is not a myth, why is the risk being underrated? I would blame this on the world’s news and literature, which focuses on high seismic regions, overshadowing other earthquakes happening in lower seismicity regions, which ironically cover about 90 per cent of the land mass in the globe.

Secondly, it is the short lifespan of humans. We do not live long enough to experience earthquakes in these lower seismicity regions. Hence, we often say there are no earthquakes in this blessed land.

Lastly, it is the legacy of British design influence. The British Isles sit on a very stable plate and are very far away from any mega earthquake source, unlike Malaysia where the Indonesian and Philippines’ subduction fault lines are just in the vicinity. Hence, it makes little sense for us not to consider earthquake risk and continue to act like an ostrich – in other words, to stick one’s head in the sand and pretend there is no problem.

Lower seismicity regions similar to Malaysia, for example, Australia, China, Singapore, Korea, and the UK, have already been practising seismic design. It is about time for Malaysia to do the same in upgrading the safety level of our building stock and to upskill civil engineers in this country in preparation for seismic design of structures.

Dr Daniel Looi Ting Wee is a civil engineering lecturer from the Faculty of Engineering, Computing and Science at Swinburne University of Technology, Sarawak Campus.