The Johor Earthquake Explained: Intraplate Quakes and Singapore’s Risk

On 24 Aug 2025, a rare earthquake rattled Johor and startled many in Singapore. How did it happen so far from the Pacific Ring of Fire, and what are the chances of it striking here?

Screengrab: Google Maps

Why Did an Earthquake Hit Johor?

On 24 Aug 2025, a magnitude-4.1 earthquake struck near Segamat in Johor at about 6:13 a.m., followed by a smaller tremor at 9:00 a.m. The Malaysian National Disaster Management Agency confirmed the quake and attributed it to the reactivation of internal crustal stress on a local fault in Peninsular Malaysia (The Straits Times).

This came as a shock because Johor and Singapore sit far from the Pacific Ring of Fire, the world’s most active earthquake zone. Yet scientists say there is another explanation.

What Is an Intraplate Earthquake?

Image: Liew, M.S., Kamaluddeen Usman Danyaro, Mazlina Mohamad, Eu Shawn Lim; via ResearchGate.

Most earthquakes occur along tectonic boundaries where plates collide, separate, or slide past one another. However, an intraplate earthquake happens inside a tectonic plate itself, far from those edges.

Tectonic plates are not flawless blocks of rock. They hold ancient fractures and weaknesses buried deep within the crust. Stress from surrounding plate movements can build up over decades or centuries. When the accumulated pressure finally breaks through a weak zone, the result is a quake—sometimes in places thought to be geologically stable.

In Johor’s case, researchers note that Peninsular Malaysia generally sits on stable ground but is not entirely immune. Studies of seismic activity from 1922 to 2020 confirm that while earthquakes are rare, intraplate events have occurred occasionally across the peninsula. Stress from the ongoing collision between the Indo-Australian and Eurasian plates can transfer far inland, triggering dormant faults (SpringerOpen Earth Sciences paper).

Famous intraplate quakes elsewhere include the 2001 Bhuj earthquake in India and the New Madrid earthquakes in the United States, both far from plate boundaries.

Could Singapore Be Hit by an Earthquake One Day?

Singapore lies on stable geology with no active faults beneath it. The likelihood of a destructive quake here is extremely low. However, powerful quakes in Sumatra have been felt in Singapore before, such as the 2007 Bengkulu earthquake that caused high-rise buildings to sway. More recently, the 2022 Pasaman quake in Sumatra was also faintly felt.

This means that while significant damage from a quake is highly unlikely, Singaporeans may occasionally experience tremors triggered by seismic events in neighboring regions.

What Are the Possibilities and Precautions?

• Faint tremors in Singapore are possible, especially from major Sumatran quakes.

• Moderate tremors are very rare, with no local historical examples of significant shaking.

• Major damage is extremely unlikely, as Singapore has no nearby active fault lines.

• Tsunami risks remain negligible, since local geography does not support such hazards.

Final Thoughts

AI Image: OpenAI

The Johor tremor was an intraplate earthquake, triggered by stress building deep within the Sunda Plate rather than at its boundary. These events are rare but show that Earth’s tectonic forces can stretch far across seemingly quiet regions. For Singapore and Johor, the good news is that the overall risk of major quakes remains low. Still, awareness of how to respond to tremors (or earthquakes, if you are overseas) is a simple step toward resilience.