20 November 2019

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

by Dr Daniel Looi Ting Wee

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

News came an hour later. A magnitude 9.1 mega earthquake struck at the offshore subduction fault of Sumatera, about 600 km away from Kuala Lumpur, which caused the Indian Ocean tsunami in 2004. If it was not Sumatra island taking the hit, sheltering the Peninsular, the casualties in Sumatra would probably be in Peninsular.

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

Through my mentor the late Ir. MC Hee, I joined the Earthquake Committee of Institution of Engineers Malaysia in 2010, who was assigned by Department of Standards Malaysia to draft the first earthquake design standard. The endeavour of 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 has not considered seismic actions at all in the past. Professor 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 examples are discussed here, “There is no earthquake in Malaysia, do not make a mountain out of molehill!”, and “Properties will be very expensive if to consider earthquake design, 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 was shared in the beginning of this article, the risk is known coming from the long-distance Sumatra 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 took place near Tubau and Miri. Let’s not forget that the rest of connected lands in Borneo (Kalimantan) had recorded some numbers of Magnitude 5 earthquake events.

For a stable plate like Malaysia, being away from the ring of fire, it does give people a false sense that either there is no earthquake, or the earthquake risk is so low until it is 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 its 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 claim are having business related interest. 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 costs implications to clients and stakeholders in order to avoid the need of any engineering up-skilling.

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

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

For design engineers, they need to jump out from their comfort zone of designing to gravity and wind actions only. Central to seismic design philosophy of buildings, it is to design buildings to have adequate energy dissipation characteristic 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 is no initial cost increase at all appears to be a naive thinking. Remember, the real cost is about casualties, repair and downtime of the building.

The discussion above is to provide the proofs 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 to the world’s news and literature which focus on high seismic regions, overshadowing other earthquakes happening in lower seismicity regions, which ironically cover about 90% of the land mass in the globe.

Secondly, it is human’s short life span. We do not live long enough to experience earthquakes in these lower seismicity regions. Hence, often we say there is no earthquake on this blessed land.

Lastly, it is the legacy of British design influence. The British Isle sits on very stable plate and is very far away from any mega earthquake source, unlike Malaysia where the Indonesia and Philippines subduction fault lines are just at the vicinity. Hence, it makes little sense for us not to consider earthquake risk and continue to practice ostrich effects, in other words, ‘to stick one’s head in the sand and pretend there is no problem’.

Lower seismicity regions similar like Malaysia, for examples, 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. Also, up-skilling of 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. He can be reached via email at dlooi@swinburne.edu.my