The earthquake of March 28, 2025 in Myanmar rekindles the alarm on the “Seismic Highway”: Sagain’s fault is a 1,200 km long threat.
The magnitude earthquake 7.7 of 28 March 2025 (followed by a second strong shock of magnitude 6.4) near Mandalay, in Myanmaroccurred along one passed fault among the plates Indiana and Eurasian. These are faults consisting of fractures in which a portion of terrestrial crusts slips laterally compared to the other. The passes of passes associated with events of the size of that of March 28 are about 160 kilometers long and twenty wide. In this case, from the first data it seems that The responsible fault is the sagaing fault, one of the most important active faults of Myanmar, or one fault parallel belonging to the same family. These structures represent A serious threat to the regiondue to their high seismic potential.
The sagaing fault extends for over 1,200 kilometers and connects the Divergent margin in the Andaman sea With the continental collision area along the Himalayan front. Crossing densely populated urban centers such as Mandalay, Naypyidaw and Yangon, a “Seismic faults” for his ability to generate significant earthquakes.
History and studies on this fault
The presence of the fault was documented for the first time at the beginning of the twentieth centurybut it is only since the 70s that geophysical studies have confirmed his crucial role in regional seismicity. Recent analyzes have estimated that along the fault there is a relative movement between the Indian plaque and that of the probe about 18 mm/year.
Sections of fault and seismic activity
The sagaing fault is divided into different sections, each with specific geological and seismic characteristics. The section southernwhich includes the segments of Bago, Pyu and Naypyidaw, it was theater of numerous destructive earthquakes during the twentieth century. In particular, the Seismic sequence of 1929-1931 It caused serious damage and losses of human lives. The section northernon the other hand, presents a complex secondary fault network who branch off from the main one, and has recorded significant events in the past, such as i earthquakes of 1906 and 1908. This area remains under observation for the still unexpressed seismic potential.
Seismic danger and seismic gaps
The fault of Sagaing represents a threat concrete for the Myanmarespecially for densely populated urban areas along its track. His geometry could encourage the propagation of “supershear” earthquakes, that is Seismic events that move at speeds higher than that of the cutting waves, thus increasing the destructive potential.
In addition, the presence of “seismic gaps” – fault segments that have not produced significant earthquakes for decades – increases the risk of events of great magnitude for the accumulated energy. In particular, the segments of Meiktila and the Andaman Sea are considered areas of particular concern.
The earthquake of March 28 rekindled the international attention on the danger of the fault. According to the first estimates of the USGS, the earthquake caused serious damage in at least three regions and caused interruptions of communications and transport. Local authorities are still evaluating the exact number of victims and displaced people.
The fault of Sagaing therefore remains a crucial element in the seismic risk assessment in Myanmar. Constant monitoring is necessary, accompanied by urban planning plans and civil protection aimed at reducing the damage of future earthquakes.
