Estimation of active surface deformation using PSInSAR technique of the Central Himalayan region

Abstract

The Kumaun Himalaya is considered as the most active part of the Central Seismic gap in the Indian Sub-continent. In this paper, we presented active surface deformation rates of the Kumaun region from February 2017 to February 2021 using the Persistent Scatterer Interferometric Synthetic Aperture Radar (PSI) technique. The cumulative displacement that occurred during the span of 4 years is ±55 mm, whereas the Line of Sight (LOS) deformation velocity rate ranges is ±7 mm/yr. Apart from PSI, we also estimated the b-value of the Kumaun region from 1803 to 2021 (399 events) and its value is 0.54 ± 0.03. A distinct NE-SW trend of b-value is observed where earthquakes with M > 6 occurred towards NE of this trend. The PSI-derived deformation reveals that the central part of the Inner Lesser Himalaya along with the Main Central Thrust (MCT) zone is dominated by uplift. The zone between the Munsiari Thrust (MT) and MCT in the central region shows the maximum uplift ranging 5–7 mm/yr which exactly lies above the mid-crustal ramp of the Main Himalayan Thrust (MHT). Our results are well corroborated with available observations of geodetic strain and peak ground acceleration values. However, the deformation patterns and high-velocity rates in the central part of the study area between MT and MCT indicate the accumulation of high stress.

Keywords:

• Deformation
• PSInSAR
• Kumaun Himalaya
• Uttarakhand
• India

Acknowledgment

GCK AP and UB are thankful to the cluster head, Department of Petroleum Engineering and Earth Science for granting necessary facilities to carry out this research work. Kapil Malk is thankful to SARPROZ. We are thankful to all receivers and to the regional Editor, Geocarto International for the constructive comments and encouragement.

Credit authorship contribution statement

GCK designed the structure of the manuscript, RSK and GCK – Conceptualization, Investigation, Methodology, Analysis, Writing. RKD, KL AJ, AT, KM, RT – Review and Editing.

Disclosure statement

On behalf of all co-authors, I declare that there is no conflict of interest between co-authors. The funding agencies are highlighted and acknowledged in the manuscript.