Synthetic Aperture Radar Interferometry to Measure Earthquake-Related Deformation: A Case Study from Nepal

Abstract

The Himalayan syntax is located at the collision boundary of the Indian and the Eurasian plates form an arc that extends ~2400 km across the continent, starting from the Kashmir Himalaya to Northeast India. Due to this collision process, there have been several significant earthquakes in the Himalayan region. To monitor earthquake-related deformation, a space-based technology, known as interferometry synthetic aperture radar (InSAR), is often employed. In this study, we demonstrate the InSAR-derived deformation rates corresponding to a moderate earthquake that occurred in the western part of Nepal near Dipayal Silgadhi (29.323°N, 81.143°E) on 19 November 2019. We use 42 interferograms covering the epicentral area with latitude ranging from 29.1°N to 29.8°N and longitude ranging from 80.5°E to 81.8°E. We calculate the line of sight (LoS) velocity and the coherence for the area along with their residuals. As a preliminary result, we observe an average upliftment of ~17.6 ± 15.5 mm/yr and subsidence of ~13.2 ± 14.4 mm/yr along the study region.