Will earthquake rattles Malay Peninsula?

This the question playing in the mind of lot of Malaysians, after witnessing the devastating jolt in Sichuan Province, China.

Western, Central and Eastern “Belts” of Peninsular Malaysia and distribution of suture zone rocks (oceanic ribbon-bedded cherts, argillites, mélange, serpentinites) and ribbon-bedded cherts, argillites and turbidites of the Semanggol Formation. Radiolarian localities and ages are also shown (after Metcalfe et al., 1999). Inset map shows the distribution of principal continental terranes and sutures of East and Southeast Asia. WB=West Burma, SWB=South West Borneo, S=Semitau Terrane, HT=Hainan Island terranes, L=Lhasa Terrane, QI=Qiangtang Terrane, QS=Qamdo-Simao Terrane, SI=Simao Terrane, SG=Songpan Ganzi accretionary complex, KL=Kunlun Terrane, QD=Qaidam Terrane, AL=Ala Shan Terrane (after Metcalfe, 1998). [Taken from Journal of Asian Earth Sciences, Volume 18, Issue 6, December 2000, Pages 691-712]

We used to be taught in school and sometimes in the media that Malaysia is free from earthquake. Is this true? The answer is yes and no. Yes, traditionally Malaysia had never be the victim of earthquake, but this does not mean that we will not have one in the future. After all, earthquake is, as the saying goes, act of god.

The fact that Malay Peninsula very existence was due to the tectonics action between two continent sub-plate, the Sibumasa terrane and the Indochina terrane make earthquake something that we cannot take it lightly. Bukit Tinggi, a small town of Pahang, situated near the Pahang-Selangor border and accessible by Karak Highway had been reporting many instances of minor quake and tremors lately. Following are the more recent news of Bukit Tinggi quakes.

21 gegaran di Bukit Tinggi cetus tanda tanya

KUALA LUMPUR 25 Mei – Kejadian gempa bumi kecil yang telah menggegarkan kawasan Bukit Tinggi, Pahang sebanyak 21 kali sejak November tahun lalu menimbulkan tanda tanya terutama di kalangan penduduk yang tinggal di kawasan sekitarnya.

Bukit Tinggi terletak dalam zon sesar bumi

KUALA LUMPUR 26 Mei – Kawasan Bukit Tinggi di Pahang yang terletak dalam zon sesar di mana lapisan bumi bergeser antara satu sama lain menjadi punca kejadian gempa kecil kerap berlaku di kawasan itu termasuk pagi semalam.

Pensyarah Jabatan Geologi, Universiti Malaya (UM), Prof. Madya Datuk Dr. Mohamad Ali Hasan berkata, lokasi itu menyebabkan Bukit Tinggi mudah menerima kesan daripada gempa bumi di negara jiran.

“Walaupun kawasan Bukit Tinggi terletak jauh dari China dan Indonesia, tetapi ia masih boleh menerima gegaran kuat di daratan berbanding kawasan lain di Malaysia.

“Ia juga boleh dikaitkan dengan tekanan persekitaran yang kuat di Asia Pasifik,” katanya kepada Utusan Malaysia hari ini.

One who is familiar to the geology of Malay Peninsula knows that, Bukit Tinggi is located at the famous Raub-Bentong suture, a fault zone. (refer to the map above) This region had been fairly stable as far as history can go, but we have to reckon that we are now experiencing extremely frequent seismic activities across the whole Asia, the magnitude 9 earthquake of Sumatra that triggered the South Asia Tsunami on Boxing Day of 2004 and the recent magnitude 8 of Sichuan may add much uncertainties to the stability of the Raub-Bentong suture.

I strongly urge that local geology experts should intensify their efforts to monitor the various fault zones in Malay Peninsula and establishing some form of early warning system to minimize damages to our population and economic, in the event of The Big One occur in Malay Peninsula.

For more information on Raub-Bentong suture, I managed tho find this journal article.

The Bentong–Raub Suture Zone by I. Metcalfe

Journal of Asian Earth Sciences
Volume 18, Issue 6, December 2000, Pages 691-712

Here I excerpted its abstract,

"It is proposed that the Bentong–Raub Suture Zone represents a segment of the main Devonian to Middle Triassic Palaeo-Tethys ocean, and forms the boundary between the Gondwana-derived Sibumasu and Indochina terranes. Palaeo-Tethyan oceanic ribbon-bedded cherts preserved in the suture zone range in age from Middle Devonian to Middle Permian, and mélange includes chert and limestone clasts that range in age from Lower Carboniferous to Lower Permian. This indicates that the Palaeo-Tethys opened in the Devonian, when Indochina and other Chinese blocks separated from Gondwana, and closed in the Late Triassic (Peninsular Malaysia segment). The suture zone is the result of northwards subduction of the Palaeo-Tethys ocean beneath Indochina in the Late Palaeozoic and the Triassic collision of the Sibumasu terrane with, and the underthrusting of, Indochina....."