Abstract A detailed characterization of the crustal deformation in the Himalaya is important to understand the tectonic and non-tectonic deformation processes responsible for the strain build-up and transients in deformation. In the present work, we have characterised the present day tectonic and non-tectonic deformations in the Kumaun Garhwal Himalaya estimated from the continuous GPS measurements. We observed strong seasonal variations in the horizontal and vertical displacement components (i.e. North, East and Vertical). The transient surface deformation estimated from global hydrological models is found to explain ~40–60% of the observed seasonal variations at sites. Plate convergence rate, and variation of slip deficit on the Main Himalayan Thrust (MHT) are calculated using site velocity estimated after removal of seasonal variations from the GPS time series. We report an excessive compression with an average principal shortening rate of −0.09 μ strain/yr in the north-northeast direction. The derived plate convergence rate is 18 ± 1 mm/yr and the width of locked frontal part of MHT is 100 ± 15 km. The quiescence of major to great earthquakes in the region since at least past 200 years and high rate of strain build up make this region vulnerable for a potentially devastating earthquake of Mw ≥ 8 in near future.

中文翻译：

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Kumaun Garhwal喜马拉雅山的构造和非构造地壳变形

摘要 喜马拉雅地壳变形的详细表征对于理解导致应变积累和变形瞬变的构造和非构造变形过程非常重要。在目前的工作中，我们已经描述了根据连续 GPS 测量估计的 Kumaun Garhwal 喜马拉雅山脉的当今构造和非构造变形。我们观察到水平和垂直位移分量（即北、东和垂直）的强烈季节性变化。发现根据全球水文模型估计的瞬态地表变形可以解释约 40-60% 的站点观测到的季节性变化。板块收敛速度，使用从 GPS 时间序列中去除季节性变化后估计的站点速度计算主喜马拉雅逆冲断层 (MHT) 上滑动赤字的变化和变化。我们报告了在北-东北方向的过度压缩，平均主要缩短率为 -0.09 μ 应变/年。推导出的板块收敛速度为 18 ± 1 mm/yr，MHT 锁定锋部宽度为 100 ± 15 km。至少在过去 200 年以来，该地区的大地震和大地震都处于静止状态，并且应变率很高，这使得该地区很容易在不久的将来发生 Mw ≥ 8 的潜在破坏性地震。推导出的板块收敛速度为 18 ± 1 mm/yr，MHT 锁定锋部宽度为 100 ± 15 km。至少在过去 200 年以来，该地区的大地震和大地震都处于静止状态，并且应变率很高，这使得该地区很容易在不久的将来发生 Mw ≥ 8 的潜在破坏性地震。推导出的板块收敛速度为 18 ± 1 mm/yr，MHT 锁定锋部宽度为 100 ± 15 km。至少在过去 200 年以来，该地区的大地震和大地震都处于静止状态，并且应变率很高，这使得该地区很容易在不久的将来发生 Mw ≥ 8 的潜在破坏性地震。