A significant earthquake, measuring M7.7, struck near Mandalay, Myanmar on March 28, 2025, at 06:20:54 UTC (12:50 local time). The event, designated as us7000pn9s by the USGS, occurred at a shallow depth of 10.0 km (USGS) and preliminary analysis indicates a strike-slip faulting mechanism (Science Media Centre). Neighboring countries, including Thailand, also experienced strong shaking, resulting in casualties and building collapses in Bangkok.

Please note: The following analysis is based on preliminary data, and we will provide updates as more information becomes available. Should seismic accelerometer data become accessible, we will utilize SeismoSoft applications to conduct a thorough analysis.

Key Technical Details:

Magnitude: 7.7 Mw
Location: 16 km NNW of Sagaing, Myanmar (22.013°N 95.922°E)
Depth: 10.0 km
Time: 2025-03-28 06:20:54 UTC
Faulting Mechanism: Strike-slip, likely along the Sagaing Fault (Science Media Centre). The finite fault solution suggests a rupture area of approximately 200 km x 20 km (USGS).
Impact: The USGS PAGER system issued a red alert for shaking-related fatalities and economic losses, indicating a high probability of extensive damage and casualties.

Implications for Structural Engineers:

Ground Motion: The shallow depth and strike-slip mechanism likely resulted in strong ground shaking over a wide area. Engineers should consider the potential for long-period ground motions, particularly for taller structures.

Building Vulnerability: The region’s building stock is characterized by a mix of vulnerable and resistant structures. Informal construction (metal, timber, etc.) and unclassified building types are likely to have suffered significant damage (USGS). Reinforced concrete structures, especially multi-story buildings, are also at risk of collapse (Science Media Centre).

Sagaing Fault: The earthquake’s proximity to the Sagaing Fault, a major strike-slip fault similar to the San Andreas Fault in California (Science Media Centre), highlights the region’s high seismic hazard. This event underscores the importance of robust seismic design and retrofitting practices in Myanmar.

Liquefaction and Landslides: The USGS estimates extensive areas affected by liquefaction and significant areas affected by potential landslides. These ground failures can exacerbate structural damage and pose additional risks.

Further Resources:

USGS Event Page: M 7.7 – 2025 Mandalay, Burma (Myanmar) Earthquake
Science Media Centre Expert Reaction: expert reaction to Myanmar earthquake | Science Media Centre

Photo/ Map by earthquake.usgs.gov