Earthquake Impact Analysis in Myanmar and Thailand

On March 28, 2025, a powerful earthquake struck Myanmar and Thailand, causing severe destruction. The National Centre for Seismology (NCS) reported that the earthquake registered a magnitude of 7.5. The epicentre was near Mandalay, Myanmar. The shaking impacted structures in both Myanmar and Thailand, particularly in Bangkok, located over 1,000 km away.

About Soil Liquefaction

Soil liquefaction is a phenomenon where saturated soil loses strength during an earthquake. It occurs when vibrations cause water to push soil particles apart. This can happen in loose, wet soils, especially near rivers or coastal areas. As a result, buildings can sink or collapse. The NCS brought into light that liquefaction was a key factor in the damage observed during this earthquake.

Effects of Earthquake Frequency

The earthquake’s shaking frequency matched the natural vibration frequency of many buildings. This resonance made structures more susceptible to damage. Buildings that are not designed to withstand such frequencies may experience severe shaking and potential collapse. The NCS indicated that this matching frequency contributed to the destruction in Bangkok.

Aftershocks and Their Significance

Following the main quake, seven aftershocks were recorded, with magnitudes ranging from 3.5 to 7. The first major aftershock occurred just 12 minutes after the primary quake. Aftershocks can exacerbate damage, leading to further structural failures. They pose ongoing risks to affected regions, complicating recovery efforts.

Historical Context of Earthquakes in the Region

The Sagaing Fault, responsible for the earthquake, is a major fault line in the region. Historical records indicate that the area has experienced earthquakes in the past, including a magnitude 7.5 quake in 1912 and a 7.2 quake in 1956. About these historical patterns is crucial for future preparedness and response strategies.

Emergency Response and Impact

In response to the earthquake, Myanmar’s military government declared a state of emergency across six regions, including Nay Pyi Taw and Mandalay. Reports indicated fatalities and extensive damage, particularly in construction areas. Emergency services were mobilised to assist those affected and assess the damage.

Geological Factors and Their Role

The Indo-Burma subduction zone, located 1,200 km from the Sagaing Fault, plays a role in the region’s seismic activity. The energy released during earthquakes can travel distances, affecting areas far from the epicentre. This geological context is vital for understanding the earthquake’s impact on neighbouring countries.

Preparedness and Future Implications

The recent earthquake marks the need for improved earthquake preparedness in the region. It puts stress on the importance of building regulations that account for soil liquefaction and resonance effects. Public awareness and education on earthquake risks are essential for minimising future casualties.

Questions for UPSC:

1. Examine the phenomenon of soil liquefaction and its implications during earthquakes.
2. Critically discuss the significance of building resonance in earthquake-prone regions.
3. Analyse the role of the Sagaing Fault in shaping seismic activity in Southeast Asia.
4. Point out the historical patterns of earthquakes in Myanmar and their impact on urban development.

Answer Hints:

1. Examine the phenomenon of soil liquefaction and its implications during earthquakes.

1. Soil liquefaction occurs when saturated soil loses its strength due to seismic vibrations.
2. It is most prevalent in loose, wet soils, particularly near rivers or coastal areas.
3. The phenomenon can lead to structural damage, including sinking or collapsing buildings.
4. In the recent earthquake, liquefaction was a major cause of damage in affected regions.
5. About liquefaction is critical for designing earthquake-resistant infrastructure.

2. Critically discuss the significance of building resonance in earthquake-prone regions.

1. Building resonance occurs when the frequency of earthquake shaking matches a building’s natural frequency.
2. This can amplify vibrations, making structures more vulnerable to damage or collapse.
3. Buildings not designed for such frequencies are at higher risk during seismic events.
4. The recent earthquake brought into light that many structures in Bangkok suffered due to this resonance effect.
5. Incorporating resonance considerations into building codes can enhance safety in earthquake-prone areas.

3. Analyse the role of the Sagaing Fault in shaping seismic activity in Southeast Asia.

1. The Sagaing Fault is a major geological fault line responsible for seismic activity in the region.
2. It is located approximately 1,200 km from the Indo-Burma subduction zone, affecting nearby countries.
3. Historical records show that the fault has generated major earthquakes, influencing regional geology.
4. The recent earthquake was directly linked to movements along the Sagaing Fault, showcasing its active nature.
5. About this fault’s dynamics is crucial for assessing future earthquake risks in Southeast Asia.

4. Point out the historical patterns of earthquakes in Myanmar and their impact on urban development.

1. Myanmar has a history of earthquakes, including notable events in 1912 and 1956.
2. These historical patterns indicate a recurring seismic threat that shapes urban planning and development.
3. Past earthquakes have led to changes in building regulations and emergency preparedness strategies.
4. Urban areas often need to adapt to seismic risks, impacting architectural designs and infrastructure investments.
5. Continued awareness of historical seismic activity is essential for mitigating future earthquake impacts.