Near-Surface Hydrologic Influences on Sagaing Fault Surface Rupture During the 2025 Mw 7.7 Mandalay, Burma (Myanmar) Earthquake

This is the authors' abstract. We don't add key points for this paper.

On 28 March 2025, the Mw 7.7 Mandalay earthquake ruptured ∼475 km of the Sagaing fault. The surface rupture was mapped using high-resolution satellite optical images guided by displacements from subpixel optical image correlation. The surface rupture was generally continuous where remotely observable (i.e., not tree-covered) and very simple without large steps or bends along strike. We analyze remote surface rupture mapping from pixel tracking and optical images and determine that ∼10% of the surface rupture passed through potentially saturated ground. The ground saturation observed on high-resolution satellite images was compared with Sentinel-2 normalized differential water index and generally agrees spatially. We test for correlations between ground saturation observations and the presence or absence of surface rupture and of strike-slip geomorphology. We infer that transient near-surface conditions, such as ground saturation, may influence the geomorphic and paleoseismic preservation of surface rupture, as well as infrastructure (dam) performance, both in this earthquake and globally.