Myanmar’s Seismic Vulnerability: Causes and Impacts

Context:

Myanmar’s frequent earthquakes, exemplified by the devastating 7.7 magnitude quake on March 28, 2025, highlight its position in a seismically active region. This susceptibility stems from its tectonic setting, making it a critical area of study for understanding earthquake dynamics and disaster preparedness in Southeast Asia.

Key Points:

• Recent Earthquake Event: On March 28, 2025, a 7.7 magnitude earthquake struck central Myanmar, followed by at least six aftershocks, killing at least 144 people and collapsing buildings in Mandalay, Myanmar’s second-largest city with 1.5 million residents.
• Regional Impact: The quake’s effects extended to Thailand, where an under-construction skyscraper in Bangkok collapsed, killing nine, and to Northeast India, which experienced tremors without significant damage or casualties.
• Epicenter and Depth: The earthquake’s epicenter was 17.2 km from Mandalay, at a shallow depth of 10 km, making it the strongest globally in two years, as per the United States Geological Survey (USGS).
• Tectonic Setting: Myanmar lies on the Alpide belt, where the Indian Plate moves north against the Eurasian Plate, causing frequent seismic activity along the Sagaing Fault, a north-south strike-slip fault through central Myanmar.
• Sagaing Fault: This fault, marking the India-Eurasia plate boundary, facilitates horizontal movement, with the Indian Plate shifting north relative to the Eurasian Plate, leading to earthquakes.
• Historical Context: Over the past century, Myanmar has experienced 14 earthquakes of magnitude 6 or higher, including a notable 8.3 magnitude quake in 1839, killing 300-400 people, seen as a historical analogue to the 2025 event.
• Seismic Frequency: Since 1900, at least six quakes above magnitude 7 have occurred near the Sagaing Fault, with the most recent prior to 2025 being a magnitude 7 event in January 1990, collapsing 32 buildings.
• Shallow Quakes’ Impact: Shallow earthquakes, like the 2025 event, cause more intense surface shaking, amplifying damage compared to deeper quakes.
• Plate Dynamics: Earth’s lithosphere comprises tectonic plates; their edges, or faults, move slowly, building stress that releases as seismic waves during earthquakes when plates slip past each other.
• Global Comparison: The 7.7 magnitude quake’s energy matches several hundred nuclear explosions, underscoring its destructive potential, felt across Southeast Asia due to its shallow depth and fault alignment.

Key Terms:

• Alpide Belt: A seismic zone from the Mediterranean to Southeast Asia, prone to earthquakes due to plate collisions.
• Sagaing Fault: A major strike-slip fault in Myanmar, driving frequent seismic activity.
• Tectonic Plates: Rigid segments of Earth’s lithosphere that move and interact, causing earthquakes.
• Strike-Slip Fault: A fault where two blocks of crust slide horizontally past each other.
• Seismic Waves: Energy waves released during an earthquake, causing ground shaking.
• Magnitude: A measure of an earthquake’s energy release, logarithmic in scale (e.g., 7.7).
• Epicenter: The point on Earth’s surface directly above an earthquake’s origin.
• Shallow Earthquake: An earthquake occurring near the surface (e.g., 10 km depth), causing stronger shaking.

Link To The Original Article – https://indianexpress.com/article/explained/explained-sci-tech/why-myanmar-is-frequently-rocked-by-earthquakes-9912160/