Tracking surface and subsurface deformation associatedwith groundwater dynamics following the 2019 Mirpurearthquake

Abstract

The Mirpur Mw 5.8 earthquake on September 24, 2019, producedextensive liquefaction-induced surface deformation (LISD) in the sur-rounding villages. Due to the complexity of seismic hazards and theoccurrence of their effects on a large spatial scale, the resulting sur-face, and subsurface deformation are often poorly resolved. To coverspatially extended LISD, the PSInSAR technique provided subsidenceand uplift rate values ranging from 110 toþ145 mm/yr consistentwith the spatial distribution of the mapped liquefaction features. Themost prominent surface change occurred in Abdupur and Sang vil-lages. GPR measurements were conducted to map the near-surfacecracks produced by transported liquified sand into the shallow sub-surface layers and other liquefaction features (elevated groundwatertable, conductive clay pockets, fractures, sand dikes, and water-enriched zones). Thus, the GPR survey assisted in the reconstructionof these structural and hydrogeological features on the near surface.In addition, the highly vulnerable zones were identified and mappedusingspace-andground-basedremotesensingmeasurementssup-ported by the field observations. The results highlight the effective-ness of the proposed novel approach for detailed assessment of thecoseismic liquefaction-induced deformation on- and near-ground sur-faces by identifying areas prone to failure during earthquakes andthereby can help with hazard mitigation.