Sagaing Fault

The Sagaing Fault is a roughly 1,400 kilometer long, mainly continental transform fault running north to south through central Myanmar, connecting seafloor spreading in the Andaman Sea to the Himalayan collision zone to the north. It marks a right lateral strike slip boundary between the Indian and Sunda plates and passes through or near the major cities of Mandalay, Naypyidaw and Yangon, making it the source of the country's most significant earthquake hazard. GPS measurements show the fault accommodating about 18 millimeters of slip per year, and it has produced repeated damaging earthquakes, including the 1839 Ava earthquake that destroyed the imperial capital, a 1946 doublet of magnitude 7.3 and 7.7, and the 2025 Myanmar earthquake, whose magnitude 7.7 to 7.9 rupture extended some 530 kilometers, the longest strike slip rupture ever precisely measured by modern instruments.