Earthquake Hits Myanmar and Thailand

Overview

• Date: March 28, 2025
• Location: Myanmar and Thailand
• Magnitude: 7.5
• Epicenter: Near Mandalay, Myanmar
• Report: National Centre for Seismology
• Effects: Soil liquefaction, building damage due to frequency matching natural vibrations

Key Concepts

Earthquake Magnitude

• Magnitude measures energy released during an earthquake.
• Scale Used: Moment Magnitude Scale (Mw)
  • Considers fault area and seismic waves size.
  • More accurate than the older Richter scale.

Soil Liquefaction

• Occurs when saturated soil loses strength during shaking.
• Affects loose, wet soils, causing structures to sink or collapse.
• Notably impacted Bangkok and surrounding areas.

Aftershocks

• Smaller earthquakes following the main event.
• Can cause additional damage and disrupt rescue operations.
• 7 aftershocks recorded, magnitudes up to 7.0.

Historical Context

• Sagaing Fault: Responsible for the earthquake.
• Past Earthquakes:
  • 1912: Magnitude 7.5
  • 1956: Magnitude 7.2
• Region has a history of seismic activity and ongoing seismic risk.

Impacts

Infrastructure and Casualties

• Severe damage reported to infrastructure.
• High-rise construction site collapse in Bangkok resulted in fatalities.
• Over 1,600 deaths in Myanmar.
• State of emergency declared by Myanmar's military government.

Seismology Techniques

• Seismographs: Used to record earthquake activity.
• Modern technology provides digitized, more accurate data.

Intensity Measurement

• Intensity measures shaking experienced at locations.
• Scales Used: Modified Mercalli Intensity scale, MSK scale
  • Classifies earthquakes from I to XII.
  • Considers human perception and structural damage, varies with distance from epicenter.