Rapid report of the March 28, 2025 M_W 7.9 Myanmar earthquake

Abstract

On March 28, 2025, a moment magnitude (M_W) 7.9 earthquake struck Myanmar, marking it as the most powerful seismic event of the year. The earthquake occurred along the Sagaing Fault, a prominent right-lateral strike-slip fault and the most significant active tectonic structure in Myanmar. In response to this seismic emergency, China Earthquake Networks Center (CENC) promptly published several reports on seismic source parameters. The focal mechanism solution indicates strike-slip faulting as the causative mechanism of the earthquake. Analysis of the rupture process indicates that it predominantly propagates from north to south. The rupture extended over a length exceeding 200 ​km and persisted for approximately 95 ​s. According to the estimated seismic intensity map, the meizoseismal region experienced shaking intensity reaching up to X(10), while the area with an intensity of more than VI exceeds 443 487 ​km². This earthquake inflicted substantial casualties and extensive property damage, underscoring the long-standing seismic hazard posed by the Sagaing Fault and highlighting the need for enhanced seismic preparedness and risk mitigation strategies in the region.

Keywords

Focal mechanism / Rupture process / Real-time intensity

CRediT authorship contribution statement

Jing Cai: Writing - original draft, Conceptualization. Nan Xi: Visualization. Guangjie Han: Formal analysis. Wenze Deng: Data curation. Li Sun: Writing - review & editing.

Author agreement and acknowledgement

On behalf of my co-authors, I would like to declare that the research described in this manuscript is original and has not been published previously. The work is also not under consideration for publication elsewhere, either in whole or in part. All authors listed have approved the enclosed manuscript. The authors thank the scientists from China Earthquake Network Center for sharing their results shortly after the earthquake. We would like to acknowledge the support of the China Earthquake Network Center Youth Science and Technology Fund (QNJJ:202320)

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

References

[1] Allen T.I., Wald D., 2007. Topographic-slope as a proxy for seismic site conditions (Vs 30) and amplification around the globe. Center for Integrated Data Analytics. Wisconsin Science Center.

[2] An Y., Wang D., Ma Q., et al., 2023. Preliminary report of the September 5, 2022, MS 6.8 Luding earthquake, Sichuan, China. Earthq. Res. Adv 3 (1), 10084.

[3] Aung P.S., Satirapod C., Andrei C.O., 2016. Sagaing Fault slip and deformation in Myanmar observed by continuous GPS measurements. Geodesy Geodyn. (1), 8. English Edition.

[4] Borcherdt R.D., 1994. Estimates of site-dependent response spectra for design (methodology and justification). Earthq. Spectra 10, 617-617. https://doi.org/10.1193/1.1585791.

[5] Chen W., Rao G., Kang D., et al., 2023. Early report of the source characteristics, ground motions, and casualty estimates of the 2023 M W 7.8 and 7.5 Turkey earthquakes. J. Earth Sci. 34 (2), 297-303.

[6] Dahlen F.A., Tromp J., 1998. Theoretical Global Seismology. Princeton University Press, Princeton, p. 178.

[7] Duputel Z., Rivera L., Kanamori H., et al., 2013. W-phase fast source inversion for moderate to large earthquakes (1990-2010). Geophys. J. Int. 189 (2), 1125-1147.

[8] Han G.J., et al., 2024. Rapid report of the December 18, 2023, MS 6.2 Jishishan earthquake, Gansu, China. Earthq. Res. Adv. 4 (2). https://doi.org/10.1016/j.Accra.2024.100287.

[9] Hara T., 2007. Magnitude determination using duration of high-frequency energy radiation and displacement amplitude: application to tsunami earthquakes. Earth Planets Space 59 (6), 561-565.

[10] Hayes G.P., Rivera L., Kanamori H., et al., 2009. Source inversion of the W-phase: real-time implementation and extension to low magnitudes. Seismol Res. Lett. 80 (5), 817-822.

[11] Ji C., Wald D.J., Helmberger D.V., 2022a. Source description of the 1999 hector mine, California, earthquake, Part I: wavelet domain inversion theory and resolution analysis. Bull. Seismol. Soc. Am. 92 (4), 1192-1207.

[12] Ji C., Wald D.J., Helmberger D.V., 2022b. Source description of the 1999 hector mine, California, earthquake, Part II: complexity of slip history. Bull. Seismol. Soc. Am. 92 (4), 1192-1207.

[13] Kagan Y.Y., 1991. 3-D rotation of double-couple earthquake sources. Geophys. J. Int. 106 (3), 709-716.

[14] Kagan Y.Y., 2005. Double-couple earthquake focal mechanism: random rotation and display. Geophys. J. Int. 163 (3), 1065-1072. https://doi.org/10.1111/j.1365-246X.2005.02781.x.

[15] Kanamori H., Rivera L., 2008. Source inversion of W phase: speeding up seismic tsunami warning. Geophys. J. Int. 175 (1), 222-238.

[16] Kundu B., Gahalaut V.K., 2012. Earthquake occurrence processes in the Indo-Burmese wedge and Sagaing fault region. Tectonophysics 524 - 525, 135-146.

[17] Maurin T., Masson F., Rangin C., et al., 2010. First GPS results in northern Myanmar: constant and localised slip rate along the Sagaing fault. Egu Gen. Assemb. 12, 4544.

[18] Tin T.Z.H., Nishimura T., Hashimoto M., Lindsey E., Aung L.T., Min S.M., et al., 2022. Present-day crustal deformation and slip rate along the southern Sagaing fault in Myanmar by GNSS observation. J. Asian Earth Sci.

[19] Wang D., Kawakatsu H., Zhuang J., et al., 2017. Automated determination of the magnitude and source, length of large earthquakes using back projection and P wave amplitudes. Geophys. Res. Lett. 44 (11).

[20] Xu L.S., Chen Y.T., 2022. Source time function and source rupture process. Seismol. Geomagn. Obs. Res. 23 (6), 8 (in Chinese).

[21] Yang H., Wang D., Guo R., et al., 2022. Rapid report of the 8 January 2022 MS 6.9 Menyuan earthquake, Qinghai, China. Earthquake Research Advances 2 (1), 11.

[22] Yang Z.G., et al., 2024. Towards fast focal mechanism inversion of shallow crustal earthquakes in the Chinese mainland. Earthq. Res. Adv. 4 (2).

[23] Zhang Y., Chen Y.T., Xu L.S., 2010. Rupture process of the 6 April 2009, L’Aquila, Italy, Mw 6.3 Earthquake-A comparison between apparent source time function method and the direct waveform inversion method Chin. J. Geophys. 53 (6), 1428-1439. (in Chinese).

[24] Zhu Y., 2022. Study on the Sagaing Fault in Southern Myanmar and the Indian Subduction Slab Based on Seismicity and Focal Mechanism Solutions. University of Chinese Academy of Sciences, Beijing.