Malaysia Maps 11 Active Earthquake Fault Zones, Targets Faster Alerts by 2026

Eleven fault zones put earthquake readiness in focus

Malaysia has mapped 11 active earthquake fault zones across the country and is working to shorten earthquake alerts from about eight minutes to six minutes by 2026. The measures bring together two parts of earthquake preparedness: identifying where the ground can move and getting information to authorities and the public more quickly after a quake.

Plantation and Commodities Minister Johari Abdul Ghani said the Minerals and Geoscience Department completed nationwide fault mapping between 2016 and 2020. Those findings are now informing building standards, infrastructure planning and emergency preparedness, giving engineers and local authorities a clearer picture of where seismic hazards need attention.

Six of the mapped active faults are in Peninsular Malaysia. Sarawak has one and Sabah has four. Authorities have also identified six states with higher exposure to seismic hazards: Pahang, Terengganu, Perak, Negeri Sembilan, Sabah and Sarawak.

Johor has become another focus following a cluster of minor earthquakes felt around Segamat and Batu Pahat in late August and September. The tremors have drawn attention to the Mersing Fault Zone and prompted plans for additional monitoring stations in the state.

As of November 27, 2025, the national effort includes updating hazard information, extending measurements of ground movement and improving earthquake and tsunami services. For residents, the practical priorities are buildings suited to local shaking conditions, dependable monitoring and familiar emergency procedures.

An active fault is a fracture in the Earth's crust where movement has occurred in recent geological time and could happen again. Its activity can appear as micro tremors too small for people to feel or as shallow earthquakes that nearby communities notice.

Where the mapped faults are located

Peninsular Malaysia's six mapped active faults stretch across several states. They are Bukit Tinggi in Pahang, Bokbak spanning Kedah and Perak, Terengganu in Terengganu, Banding in Perak, Kuala Pilah in Negeri Sembilan, and Mersing in Johor.

Sarawak's mapped structure is the Tubau Fault in Miri. Sabah's four are Lobou Lobou and Mensaban in Ranau, together with Lahad Datu and Tabin in the Lahad Datu area. Identifying these structures helps authorities estimate how strong nearby shaking could be and how often it might occur.

Six active fault movement benchmark stations have been installed in Sabah to track subtle ground movement. Authorities also operate 47 passive stations across Pahang, Selangor, Perak, Negeri Sembilan, Sarawak and Sabah. These measurements support surveillance of changes in the ground across fault systems.

Plans are underway to extend both fault mapping and benchmark coverage to other districts with higher risk, including parts of Johor. The maps and instruments support updated hazard models, infrastructure decisions and guidance for engineers using the Malaysia National Annex to Eurocode 8.

Why shaking reaches a relatively stable peninsula

Peninsular Malaysia sits on a relatively stable part of the Eurasian Plate, yet earthquakes can still affect it. A major reason is its proximity to Sumatra, where the Sunda megathrust and the Sumatran fault zone generate large earthquakes. Energy from those events travels across the Strait of Malacca and can produce light to moderate shaking in western and central parts of the peninsula.

Local faults also release stress from time to time. These are described as intraplate faults because they lie within a tectonic plate. Their proximity to towns and infrastructure adds to the risk even when the earthquakes they produce are smaller than those originating in Sumatra.

Peer reviewed studies using deterministic and probabilistic hazard methods have found higher peak ground acceleration values in cities between roughly two and four degrees north latitude, including the Klang Valley corridor, than in other parts of the peninsula. The main influence is nearby Sumatran earthquake sources. Deterministic methods examine shaking from particular earthquake scenarios, while probabilistic methods consider how likely different levels of shaking are over time.

Reservoir induced earthquakes have also been recorded near major dams such as Kenyir and Temenggor. These usually involve small to moderate tremors. Changes in water pressure within rock layers can alter stress along existing faults and trigger movement.

Malaysia's hazard assessment therefore has to consider several sources of shaking: large earthquakes across the strait, movement on local faults and tremors associated with reservoirs. Their effects vary by location, which makes detailed mapping useful for decisions about buildings and infrastructure.

What the Johor tremors mean for local preparedness

Segamat and Batu Pahat experienced tremors during the cluster of minor earthquakes in late August and September. Recorded magnitudes ranged roughly from 2.5 to 4.1, and the earthquakes were shallow. Engineers describe them as a natural release of tectonic energy along older fault structures.

The events drew attention to the Mersing Fault Zone, which runs through eastern Johor. Based on current data, expected shaking intensity in areas such as Segamat and Batu Pahat is moderate at most. Authorities say routine monitoring and appropriate building standards remain the focus.

Pahang, Terengganu, Perak, Negeri Sembilan, Sabah and Sarawak have been flagged for higher exposure to seismic hazards. Local authorities in these states need to apply modern design standards and strengthen monitoring where faults and population centers intersect.

Johor's recent tremors give that work an immediate local focus. The planned expansion of mapping and monitoring will provide more information about small earthquakes and ground movement, while building decisions continue to depend on the conditions at each location.

How hazard maps become building requirements

Seismic hazard maps turn geological information into numbers engineers can use. A key measure is peak ground acceleration, or PGA, which describes how strongly the ground accelerates during shaking. Maps estimate the shaking a site might experience over a given timeframe, using return periods such as 475 years and 2,475 years.

Recent academic work combining distant Sumatran earthquake sources with local faults estimates PGA on rock sites across Peninsular Malaysia at about 1 to 10 percent g for the 475 year level and about 2 to 20 percent g for the 2,475 year level. The symbol g refers to acceleration caused by gravity, providing a reference for expressing the strength of ground movement.

Those ranges show why engineers need local hazard values. A single number for the whole country would miss differences between districts. Local authorities use the mapped values to set requirements for new construction and to decide which existing buildings should receive priority for strengthening.

Malaysia's design practice references the Malaysia National Annex to Eurocode 8, the standard used to design structures for earthquake resistance. It provides guidance on structural systems, ductility, detailing and site classification so buildings can withstand the shaking anticipated at their location.

Ductility describes a structure's ability to deform while continuing to carry loads. Detailing concerns how its parts and connections are arranged. Site classification accounts for ground conditions, which matter because buildings on different soils can respond differently to the same earthquake.

For complex urban areas, experts recommend microzonation: mapping soil conditions and fault proximity at a finer scale. This can identify neighborhoods where softer soils may increase shaking and guide design checks for essential facilities such as hospitals, schools and bridges.

Faster alerts and stronger monitoring in Johor

The Malaysian Meteorological Department, known as MetMalaysia, operates 80 seismographic stations at strategic locations nationwide. Its system also receives data in real time from 323 international stations, extending the information available for detecting and assessing earthquakes in and near Malaysia.

The system issues alerts within about eight minutes for earthquakes of magnitude 3.0 or larger occurring in or near the country. Under the current national plan, upgrades aim to bring that time down to about six minutes by 2026. Reaching the target would shorten the stated alert time by two minutes, or one quarter.

Twelve seismic monitoring stations are being strengthened as part of the wider improvement program. In Johor, two new stations are planned in Segamat and Muar. Four existing stations in Johor Bahru, Batu Pahat and Gelang Patah are also being upgraded to improve detection of local earthquakes with low magnitudes.

Data transmission uses satellite links to maintain continuity during storms or power disruptions. Reliable transmission matters because instruments must send their readings to the monitoring system for the information to support timely alerts.

The main milestones connect completed geological work with the next monitoring target:

• 2016 to 2020: The Minerals and Geoscience Department completed nationwide fault mapping.
• Late August and September: Minor earthquakes around Segamat and Batu Pahat drew attention to the Mersing Fault Zone.
• November 27, 2025: Malaysia's preparedness effort includes updated hazard information, expanded monitoring and station upgrades.
• 2026: The national plan targets earthquake alerts within about six minutes.

Faster alerts can help responders put essential services on standby, temporarily halt rail lines for inspections and send guidance to schools and hospitals. When shaking is felt without causing damage, prompt official information can also calm rumors and reduce unnecessary evacuations.

Earthquakes cannot be predicted. Tsunamis, however, can be detected and tracked after undersea earthquakes. Early warning investment therefore covers both seismic detection and sea level monitoring, alongside clear procedures for delivering alerts to authorities and the public.

Sabah and Sarawak face different local challenges

Sabah has experienced damaging earthquakes in living memory, including the 2015 event near Ranau that triggered rockfalls on Mount Kinabalu. Its four mapped active faults are concentrated in the Ranau and Lahad Datu areas, making those locations important for monitoring and planning.

Sabah's steep landscape and housing stock, which includes substantial lightweight construction, affect how structures respond to shaking. The state's six active fault movement benchmark stations support close surveillance of deformation across its fault systems.

Sarawak's Tubau Fault near Miri is the state's main mapped structure. Both Borneo states are covered by an expanding benchmark network that tracks slow ground movement, adding information that can be used alongside earthquake recordings and hazard maps.

Local governments in East Malaysia increasingly use hazard information for land use and site selection. Their planning includes avoiding known fault traces when choosing sites for critical facilities and raising construction standards where needed. These decisions connect the geological work directly to where facilities are built and how they are designed.

Which buildings and services need attention

Engineers and local authorities are being urged to apply the Malaysia National Annex to Eurocode 8 consistently to public buildings, structures used by large numbers of people and essential infrastructure. Proper geotechnical investigations on new projects help establish the ground conditions needed for design decisions.

Hospitals, emergency centers and major bridges may also need response spectra tailored to their sites where practical. A response spectrum describes how structures respond to different shaking motions, helping engineers match a design to the anticipated earthquake conditions.

Older buildings in towns near mapped faults need preliminary assessments to identify vulnerable features. Priorities include soft story configurations, where one level is less resistant to sideways movement than others; masonry without reinforcement; and concrete frames with limited ability to deform during shaking.

Heavy components that do not form part of a building's main structure also need attention. Parapets and partitions without bracing can pose risks during shaking. Simple measures such as bracing water tanks and securing equipment can reduce those risks.

More detailed microzonation is recommended for urban areas within the corridor of higher PGA values. These include the Klang Valley, Seremban, Melaka, Ipoh, Penang and Johor Bahru, as well as growing Johor towns such as Segamat and Kluang. The results can inform planning approvals and emergency response plans.

Essential services require similar checks. Power substations, water treatment plants, pipelines, elevated tanks, telecommunications hubs and transport viaducts are priorities for seismic assessment. Where weaknesses are found, strengthening programs can be introduced in phases, starting with the most cost effective measures.

Public education remains part of the same effort. Programs should explain what to do during shaking, how to prepare at home and at work, and how official alerts are delivered. Familiar procedures help people respond more quickly and calmly when an event occurs.

Vigilance, updated maps and steady improvements

Seismic engineering expert Dr Azlan Adnan has urged vigilance, updated hazard maps and more detailed studies in urban centers close to mapped faults or within corridors exposed to Sumatran earthquake sources. He explained the combination of nearby regional activity and older local structures:

The country lies near a major seismic zone in Sumatra and also has legacy fault lines within the peninsula which can occasionally reactivate.

Dr Azlan's advice to the public was concise:

It is a time to be vigilant, not to panic.

Government officials say the national hazard map is being refreshed and seismic and tsunami services are being improved under the current development plan. The goals are faster detection, richer data for engineers and steady improvements in standards as new geological information becomes available.

Key Points

• Malaysia has mapped 11 active fault zones: six in Peninsular Malaysia, one in Sarawak and four in Sabah.
• Nationwide fault mapping was completed between 2016 and 2020 and now informs construction, infrastructure planning and preparedness.
• Pahang, Terengganu, Perak, Negeri Sembilan, Sabah and Sarawak are flagged for higher seismic exposure.
• Authorities operate six active fault movement benchmark stations in Sabah and 47 passive stations across six states.
• MetMalaysia uses 80 domestic seismographic stations and data from 323 international stations. Alerts take about eight minutes, with a target of six minutes by 2026.
• Twelve monitoring stations are being strengthened. Johor is due to receive new stations in Segamat and Muar, alongside upgrades to four existing stations.
• The Malaysia National Annex to Eurocode 8 and local hazard maps guide earthquake resistant design.
• Earthquakes cannot be predicted. Monitoring, tsunami detection, suitable construction and public readiness remain the main preparedness measures.