Interseismic coupling on the main Himalayan thrust

• Published in: Geophysical research letters Vol. 42; no. 14; pp. 5828 - 5837
• Main Authors: Stevens, V. L., Avouac, J. P.
• Format: Journal Article
• Language: English
• Published: Washington Blackwell Publishing Ltd 28.07.2015; John Wiley & Sons, Inc
• Subjects: Accumulation; Banks (topography); Convergence; Coupling; Earthquake construction; Estimates; Geodetics; Geomorphology; GPS; Himalaya; Interferometric synthetic aperture radar; Interferometry; interseismic coupling; Joining; Length; Mathematical models; Plate tectonics; Propagation; Radar; SAR (radar); Segmentation; seismic hazard; Seismology; Slip; Slope; Strain; Synthetic aperture radar; tectonics; Thrust; Topography; Topography (geology); Uplift; Width; Pakistan, Himalayas
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1002/2015GL064845

We determine the slip rate and pattern of interseismic coupling on the Main Himalayan Thrust along the entire Himalayan arc based on a compilation of geodetic, interferometric synthetic aperture radar, and microseismicity data. We show that convergence is perpendicular to the arc and increases eastwards from 13.3 ± 1.7 mm/yr to 21.2 ± 2.0 mm/yr. These rates are comparable to geological and geomorphic estimates, indicating an essentially elastic geodetic surface strain. The interseismic uplift rate predicted from the coupling model closely mimics the topography, suggesting that a small percentage of the interseismic strain is permanent. We find that the fault is fully locked along its complete length over about 100 km width. We don't find any resolvable aseismic barrier that could affect the seismic segmentation of the arc and limit the along‐strike propagation of seismic ruptures. The moment deficit builds up at a rate of 15.1 ± 1 × 1019 N m/yr for the entire length of the Himalaya. Key Points The whole Himalayan arc is locked to roughly 100 km width, with no resolvable aseismic patches GPS and geomorphic shortening rates are comparable, indicating an elastic geodetic surface strain The moment deficit builds up at a rate of 15.1 ± 1 × 1019 Nm/yr for the entire arc