16 research outputs found
Locked and loading megathrust linked to active subduction beneath the Indo-Burman Ranges
The Indo-Burman mountain rangesmarkthe boundary between the Indian and Eurasian plates, north of the Sumatra–Andaman subduction zone. Whether subduction still occurs along this subaerial section of the plate boundary, with 46mm/yr of highly oblique motion, is contentious. About 21mm/yr of shear motion is taken up along the Sagaing Fault, on the eastern margin of the deformation zone. It has been suggested that the remainder of the relative motion is taken up largely or entirely by horizontal strike-slip faulting and that subduction has stopped. Here we present GPS measurements of plate motions in Bangladesh, combined with measurements from Myanmar and northeast India, taking advantage of a more than 300 km subaerial accretionary prism spanning the Indo-Burman Ranges to the Ganges–Brahmaputra Delta. They reveal 13–17mm/yr of plate convergence on an active, shallowly dipping and locked megathrust fault. Most of the strike-slip motion occurs on a few steep faults, consistent with patterns of strain partitioning in subduction zones. Our results strongly suggest that subduction in this region is active, despite the highly oblique plate motion and thick sediments. We suggest that the presence of a locked megathrust plate boundary represents an underappreciated hazard in one of the most densely populated regions of the world
Sensitivity of launch systems to gravity field
This paper considers the question of how sensitive inertially guided systems are to variations in the gravity field. There are systems which use other kinds of information for guidance, such as terrain. But, they will not be considered here
The need for geodetic observations to constrain the relative motion of the Indian tectonic plate
The prediction errors of recent geodynamic plate motion modelling and a study of the relative importance of data on boundaries devoid of plate motion data reveal that the India-Eurasia boundary is of utmost importance for better geodynamic modelling. Examination of the influence of some hypothetical very long baseline interferometry (VLBI) measurements involving an Indian station clearly demonstrates the improvement in modelling which may be achieved if such measurements are made
Contemporary deformation in the Kashmir–Himachal, Garhwal and Kumaon Himalaya: significant insights from 1995–2008 GPS time series
Locked and loading megathrust linked to active subduction beneath the Indo-Burman Ranges
Detailed geometry of the subducting Indian Plate beneath the Burma Plate and subcrustal seismicity in the Burma Plate derived from joint hypocenter relocation
Crustal shortening in convergent orogens: Insights from global positioning system (GPS) measurements in northeast India
Himalayan strain reservoir inferred from limited afterslip following the Gorkha earthquake
The magnitude 7.8 Gorkha earthquake in April 2015 ruptured a 150-km-long section of the Himalayan décollement terminating close to Kathmandu The earthquake failed to rupture the surface Himalayan frontal thrusts and raised concern that a future Mw ≤ 7.3 earthquake could break the unruptured region to the south and west of Kathmandu. Here we use GPS records of surface motions to show that no aseismic slip occurred on the ruptured fault plane in the six months immediately following the earthquake. We find that although 70 mm of afterslip occurred locally north of the rupture, fewer than 25 mm of afterslip occurred in a narrow zone to the south. Rapid initial afterslip north of the rupture was largely complete in six months, releasing aseismic-moment equivalent to a Mw 7.1 earthquake. Historical earthquakes in 1803, 1833, 1905 and 1947 also failed to rupture the Himalayan frontal faults, and were not followed by large earthquakes to their south. This implies that significant relict heterogeneous strain prevails throughout the Main Himalayan Thrust. The considerable slip during great Himalayan earthquakes may be due in part to great earthquakes tapping reservoirs of residual strain inherited from former partial ruptures of the Main Himalayan Thrust