How did the Myanmar earthquake occur?

(Source – The Hindu, International Edition – Page No. – 10)

Topic: GS1 – Geography

Context

A powerful 7.7-magnitude earthquake struck central Myanmar on March 28, 2025, about 20 km from Mandalay.

Overview of the Earthquake

• The Sagaing fault, one of the most seismically active faults in the region, was the source of the earthquake.

• Several aftershocks, including a 6.4-magnitude tremor, followed within minutes.

Impact of the Earthquake

• The earthquake caused widespread devastation, resulting in thousands of deaths and extensive destruction of homes and infrastructure.

• Mandalay, with a population of 1.5 million, was the hardest hit, with severe damage to pagodas, mosques, and bridges.

• The U.S. Geological Survey estimated a death toll exceeding 10,000 in the affected regions.

Why Some Areas Were More Affected

• The southern part of the Sagaing fault experienced more damage due to thicker alluvial soil, which amplified seismic energy.

• China’s Yunnan Province and eastern India were spared major destruction because of different geological conditions and the north-south dispersal of seismic energy.

Earthquake Activity in South Asia

• South Asia is prone to earthquakes due to its location near major tectonic features such as the Himalayas, Shillong Plateau, Indo-Burman Range, and Andaman-Nicobar subduction zone.

• The Indian and Eurasian Plates have been colliding for 40 million years, leading to frequent earthquakes.

• Notable past earthquakes include:

  • 1792 Arakan earthquake (8.5-magnitude) – caused a tsunami in the Bay of Bengal.

  • 2004 Sumatra earthquake (9.2-magnitude) – generated a devastating tsunami.

Sagaing Fault and its Geodynamics

• The Sagaing fault runs 1,400 km and is a strike-slip fault, meaning tectonic blocks slide past each other horizontally.

• It accommodates 50-55% of plate motion in the region, with a slip rate of 15-25 mm per year.

• The San Andreas fault in the U.S. is another example of such a fault.

Historical Earthquakes on the Sagaing Fault

• The region has experienced multiple earthquakes, including:

  • 1839 Ava earthquake (7.8-magnitude) – killed over 500 people.

  • 1927 earthquake – strongly felt north of Yangon.

  • 1946 earthquake (7.7-magnitude) – similar in magnitude to the 2025 quake.

  • 2016 Bagan earthquake – damaged historic religious monuments.

Lessons for India

• Myanmar’s earthquake serves as a warning for India, which is one of the most earthquake-prone countries in South Asia.

• India must implement scientifically tested safety measures to reduce earthquake damage and protect lives and infrastructure.

PYQ: Why are the world’s fold mountain systems located along the margins of continents? Bring out the association between the global distribution of Fold Mountains and the earthquakes and volcanoes. (150 words/10m) (UPSC CSE (M) GS-1 2014)

Practice Question: Discuss the geological significance of the Sagaing fault in Myanmar and its role in triggering major earthquakes. What lessons can India learn from the 2025 Mandalay earthquake to improve its earthquake preparedness? (250 Words /15 marks)