1912 Maymyo earthquake

The 1912 Maymyo earthquake or Burma earthquake struck Burma on the morning of May 23, with an epicentre near Taunggyi and Pyin Oo Lwin in Shan State. The earthquake was initially calculated at 8.0 on the surface-wave magnitude scale (Ms/) by Beno Gutenberg and Charles Francis Richter, and described by them as being one of the most remarkable seismic events in the early 1900s. Recent re-evaluation of the earthquake, however, have revised the magnitude to 7.6 7.9. It was preceded by two foreshocks on May 18 and 21 with respective intensities V and VII on the Rossi Forel scale, while the mainshock was assigned IX. Shaking was felt throughout most of Burma, parts of Siam and Yunnan; an area covering approximately 375,000 square miles. It was one of the largest earthquakes in the country.

The 1912 Maymyo Earthquake

The 1912 Maymyo earthquake, also referred to as the Burma earthquake, occurred on the morning of May 23, striking Burma with an epicenter near Taunggyi and Pyin Oo Lwin in Shan State. Initially, the earthquake was measured at a magnitude of 8.0 on the surface-wave magnitude scale by seismologists Beno Gutenberg and Charles Francis Richter. They regarded it as one of the most significant seismic events of the early 1900s. However, recent evaluations have adjusted the magnitude to between 7.6 and 7.9.

The earthquake was preceded by two foreshocks on May 18 and May 21, which had intensities of V and VII on the Rossi–Forel scale, respectively, while the mainshock was rated IX. The shaking was felt across much of Burma, parts of Siam, and Yunnan, affecting approximately 375,000 square miles, making it one of the largest earthquakes in the region.

Tectonic Setting

Myanmar is located at the convergence of four tectonic plates: the Indian, Eurasian, Sunda, and Burma plates. The Sunda megathrust, a significant fault line, marks the boundary between the Indian and Burma plates, extending from the seafloor in Bangladesh and running parallel to the Chin Hills. This fault converges in the northern region of Myanmar, culminating at the eastern Himalayas.

The Sagaing Fault, a north-south trending strike-slip fault, facilitates half of the tectonic movement between the Indian and Sunda landmasses. The research has shown varying slip rates, suggesting a slip accumulation period that could span thousands of years.

The Earthquake

Gutenberg and Richter had initially estimated the 1912 earthquake’s magnitude at 8.0 in their 1954 publication, “Seismicity of the Earth and Associated Phenomena”. However, subsequent studies in 1983 and 1992 adjusted this to 7.6–7.7. Other estimates, including 7.9 from the journal “Secular Seismic Energy Release in the Circum-Pacific Belt”, further add to the complexity of its measurement.

Geological investigations indicated that a railway was displaced in Kyaukkyan village, linked to the earthquake’s surface rupture. Nevertheless, significant uncertainties remain regarding the exact fault responsible for the event.

Impact

The casualty count from the earthquake remains unclear, with the National Earthquake Information Center cataloging “few” deaths, estimated between 1 and 50.

Pyin Oo Lwin

Witnesses reported hearing thunder during the earthquake. Damage was extensive, with bricks and plaster falling from the Governor’s House, and severe structural damage to local hospitals. The seismic intensity likely reached VIII–IX. Additionally, a major rockslide disrupted services on the Burma Railway.

Mandalay

Many residents struggled to maintain their balance as the shaking intensified to IX on the Rossi–Forel scale. Several buildings suffered extensive damage, including a cathedral and the Wesleyan School.

Taunggyi

In Taunggyi, the shock persisted for over a minute, causing critical damage to military buildings and a widespread collapse of chimneys.

Mogok

Here, the quake caused cracks in brick structures and the collapse of several pagodas, alongside landslides that disrupted local infrastructure.

Other Areas

Shaking was felt across several regions, including Shan State and Bago Region, with intensities of VI–VII. In contrast, areas farther away, such as Rangoon, barely perceptibly felt the quake, with reports of swinging lamps and disrupted water and oil in local communities.

Conclusion

The 1912 Maymyo earthquake remains a pivotal event in Myanmar’s seismic history, highlighting the region’s complex tectonic activity and the challenges of accurately assessing historical seismic events.