The 28 March 2025 Mw 7.7 Myanmar earthquake: spatio-temporal rupture evolution and source characteristics.
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| Title: | The 28 March 2025 Mw 7.7 Myanmar earthquake: spatio-temporal rupture evolution and source characteristics. |
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| Authors: | Kumar, Ajay1 (AUTHOR), Chaudhuri, Dibyajyoti2 (AUTHOR), Banerjee, Rupak2 (AUTHOR), Mondal, Sankarshan2 (AUTHOR), Shamim, Sk.2 (AUTHOR), Yadav, Tarak2 (AUTHOR), Mitra, Supriyo2,3 (AUTHOR) supriyomitra@iiserkol.ac.in |
| Source: | Journal of Earth System Science. Jun2026, Vol. 135 Issue 2, p1-16. 16p. |
| Subject Terms: | *Earthquakes, *Geologic faults, *Earthquake hazard analysis, *Surface fault ruptures, *Earthquake zones, *Earthquake aftershocks |
| Geographic Terms: | Myanmar |
| Abstract: | The 28 March 2025 Mw 7.7 earthquake in Myanmar occurred along the N–S striking Sagaing Fault near Mandalay and ruptured a previously identified 'seismic gap'. This shallow, bilateral rupture spanned ∼ 400 km and lasted about 80 s. The rupture initially propagated northward at sub-shear speed and then transitioned to a super-shear southward rupture, which likely sustained the rupture on such a long fault. The mainshock was followed by a significant Mw 6.7 aftershock just 11 minutes later. Teleseismic-waveform-data analysis of the mainshock revealed three distinct sub-events, with the central one (10–40 s) contributing the most energy and dominating the radiation pattern. A frequency-dependent radiation is observed for the super-shear southern rupture, which ended in oblique–slip. The mainshock seismic moment is ∼ 6.26 × 10 20 N.m, and moment magnitude is 7.79. The average slip on the fault is ∼ 2 m, with stress-drop of ∼ 15 ± 5 bars. Source directivity analysis indicated stronger ground motion to the south, consistent with the super-shear rupture. The mainshock not only released the strain, accumulated over decades, on the Sagaing Fault, but potentially increased stress on the adjacent, fully-locked Rakhine-Bangladesh megathrust. This has major implications for seismic hazard in Bangladesh and northeast India. [ABSTRACT FROM AUTHOR] |
| Database: | Energy & Power Source |
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| Abstract: | The 28 March 2025 Mw 7.7 earthquake in Myanmar occurred along the N–S striking Sagaing Fault near Mandalay and ruptured a previously identified 'seismic gap'. This shallow, bilateral rupture spanned ∼ 400 km and lasted about 80 s. The rupture initially propagated northward at sub-shear speed and then transitioned to a super-shear southward rupture, which likely sustained the rupture on such a long fault. The mainshock was followed by a significant Mw 6.7 aftershock just 11 minutes later. Teleseismic-waveform-data analysis of the mainshock revealed three distinct sub-events, with the central one (10–40 s) contributing the most energy and dominating the radiation pattern. A frequency-dependent radiation is observed for the super-shear southern rupture, which ended in oblique–slip. The mainshock seismic moment is ∼ 6.26 × 10 20 N.m, and moment magnitude is 7.79. The average slip on the fault is ∼ 2 m, with stress-drop of ∼ 15 ± 5 bars. Source directivity analysis indicated stronger ground motion to the south, consistent with the super-shear rupture. The mainshock not only released the strain, accumulated over decades, on the Sagaing Fault, but potentially increased stress on the adjacent, fully-locked Rakhine-Bangladesh megathrust. This has major implications for seismic hazard in Bangladesh and northeast India. [ABSTRACT FROM AUTHOR] |
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| ISSN: | 02534126 |
| DOI: | 10.1007/s12040-026-02754-y |
