An extract from my report for your casual reading. In the early years of modern construction, Malaysia has not prioritizing Seismic Hazard Assessment since the nation is considered to have very low seismicity with exception of Sabah which is quite exposed to earthquake and seismic activities coming from seas and ocean surrounded it. Earthquake data for Malaysia only began since 1976 with the implementation of Seismological Program for Southeast Asia (SEA) sponsored by UNESCO withseven seismological stations using short period vertical component seismographs to monitor seismic activities in the country and surrounding areas. Prior to this, data are correlated based from earthquake data from the Philippines which were used for construction of several structures especially the Kinabatangan Bridge and the Segama Bridge during the 60’s. Under the Earthquake Hazard Mitigation Program which was undertaken by the Southeast Asia Association of Seismology and Earthquake Engineering (SEASEE) from 1982 to 1984, a few seismological studies were carried out including the production of a seismotectonic map for Malaysia. Based on historical data, an attempt was made to derive appropriate earthquake intensity according to the Modified Mercalli (MM) Scale. This is the foundation of the Maximum Observed Intensity maps for Peninsular Malaysia (Malaya), Sabah and Sarawak. The down side to the short period covered by available records and low rate of earthquake occurrence, it is relatively difficult to embark on Seismic Hazard Assessment or Seismic Zoning of the country. Until date of the Maximum Observed Intensity map production, Sabah had only experienced five (5) local earthquakes between 1976 and 1990. Therefore, such adequacy did hamper the accuracy of the zoning. During that point of time, Lahad Datu, Semporna and Tawau were classified to be under Class VII of the MM Scale as shown in Figure 1. MM Scale grouped the intensity to possible Richter scale as per Figure 4 and Figure 5. The Study by Leyu (2008) have produced another Maximum Observed Intensity Map of Sabah and Sarawak (1875-2007) which saw an increase of the classification surrounding Dent-Semporna Peninsular Zone to Class VIII with PGA (0.25 to 0.30g) with Pulau Mabul sitting at the borderline of the demarcation; at Class VII with PGA of 0.10 to 0.15g. The basis of such result is based on earthquakes occurred at the bay between Lahad Datu and Kunak on the 26th July 1976 at six epicenters with the highest magnitude of 5.8 Richter Scale along Lahad Datu active fault line. In 2015, N.S.H. Harith, A. Adnan and A.V. Shoushtari produced their research work entitled “Seismic Hazard Assessment of East Malaysia Region” which is the foundation to the annexed map of peak ground acceleration for Sabah and Sarawak for the Malaysian Annex Eurocode 1998 Part 1 which is based on 10% probability of exceedance as per Figure 3B.
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