We document geodetic strain across the Nepal Himalaya using GPS times series from 30 stations in Nepal and southern Tibet, in addition to previously published campaign GPS points and leveling data and determine the pattern of interseismic coupling on the Main Himalayan Thrust fault (MHT). The noise on the daily GPS positions is modeled as a combination of white and colored noise, in order to infer secular velocities at the stations with consistent uncertainties. We then locate the pole of rotation of the Indian plate in the ITRF 2005 reference frame at longitude = − 1.34° ± 3.31°, latitude = 51.4° ± 0.3° with an angular velocity of Ω = 0.5029 ± 0.0072°/Myr. The pattern of coupling on the MHT is computed on a fault dipping 10° to the north and whose strike roughly follows the arcuate shape of the Himalaya. The model indicates that the MHT is locked from the surface to a distance of approximately 100 km down dip, corresponding to a depth of 15 to 20 km. In map view, the transition zone between the locked portion of the MHT and the portion which is creeping at the long term slip rate seems to be at the most a few tens of kilometers wide and coincides with the belt of midcrustal microseismicity underneath the Himalaya. According to a previous study based on thermokinematic modeling of thermochronological and thermobarometric data, this transition seems to happen in a zone where the temperature reaches 350°C. The convergence between India and South Tibet proceeds at a rate of 17.8 ± 0.5 mm/yr in central and eastern Nepal and 20.5 ± 1 mm/yr in western Nepal. The moment deficit due to locking of the MHT in the interseismic period accrues at a rate of 6.6 ± 0.4 × 10¹⁹Nm/yr on the MHT underneath Nepal. For comparison, the moment released by the seismicity over the past 500 years, including 14M_W≥ 7 earthquakes with moment magnitudes up to 8.5, amounts to only 0.9 × 10¹⁹Nm/yr, indicating a large deficit of seismic slip over that period or very infrequent large slow slip events. No large slow slip event has been observed however over the 20 years covered by geodetic measurements in the Nepal Himalaya. We discuss the magnitude and return period of M > 8 earthquakes required to balance the long term slip budget on the MHT.

Using the measurements of 750 GPS stations around the Tibetan Plateau for over 10 years since 1999, we derived a high‐resolution 3‐D velocity field for the present‐day crustal movement of the plateau. The horizontal velocity field relative to stable Eurasia displays in details the crustal movement and tectonic deformation features of the India‐Eurasia continental collision zone with thrust compression, lateral extrusion, and clockwise rotation. The vertical velocity field reveals that the Tibetan Plateau is continuing to rise as a whole relative to its stable north neighbor. However, in some subregions, uplift is insignificant or even negative. The main features of the vertical crustal deformation of the plateau are the following: (a) The Himalayan range is still rising at a rate of ~2 mm/yr. The uplift rate is ~6 mm/yr with respect to the south foot of the Himalayan range. (b) The middle eastern plateau has a typical uplift rate between 1 and 2 mm/yr, and some high mountain ranges in this area, like the Longmen Shan and Gongga Shan, have surprising uplift rates as large as 2–3mm/yr. (c) In the middle southern plateau, there is a basin and endorheic subregion with a series of NS striking normal faults, showing obvious sinking with the rates between 0 and ‐3 mm/yr. (d) The present‐day rising and sinking subregions generally correspond well to the Cenozoic orogenic belts and basins, respectively. (e) At the southeastern corner of the plateau. There is an apparent trend that the uplift rate is gradually decreasing from between 0.8 and 2.3 mm/yr in the inner plateau to between ‐0.5 and ‐1.6 mm/yr outside the plateau, with the decrease of terrain height.

We quantify the bulk topographic characteristics of the Tibet‐Qinghai plateau with specific focus on three representative regions: northern, central, and southeastern Tibet. Quantitative landscape information is extracted from Shuttle Radar Topography Mission digital elevation models. We find that the morphology of the Tibetan plateau is nonuniform with systematic regional differences. The northern and central parts of the plateau are characterized by what we suggest to call “positive topography,” i.e., a topography in which elevation is positively correlated with relief and mean slope. A major change from the internally drained central part of Tibet to the externally drained part of eastern Tibet is accompanied by a transition from low to high relief and from positive to “negative topography,” i.e., a topography where there is an inverse or negative correlation between elevation and relief and between elevation and mean slope. Relief in eastern Tibet is largest along rivers as they cross an ancient, eroded plateau margin at high angle to the major strike‐slip faults, the Yalong‐Yulong thrust belt, implying strong structural control of regional topography. We propose that the evolution of river systems and drainage efficiency, the ability of rivers to transport sediments out of the orogen, coupled with tectonic uplift, is the simplest mechanism to explain systematic regional differences in Tibetan landscapes. Basin filling due to inefficient drainage played a major role in smoothing out the tectonically generated structural relief. This mode of smoothing started concurrently with tectonic construction of the relief, as most clearly illustrated today in the Qilian Shan‐Qaidam region of the northeastern plateau. In the interior of Tibet, further “passive” filling, due to internal drainage only, continued to smooth the local relief millions of years after the cessation of major phases of surface uplift due to crustal shortening. Thus, diachronous beveling at high elevation produced the low‐relief surface of the high plateau. In southeast Tibet, headward retreat of external drainages brought back “in” the global ocean base level, first disrupting then interrupting the relief‐reduction process. It produced a transitional topography by dissecting the “old” remnant plateau surface, which introduced younger and steeper incision of this hitherto preserved high base level. This provides a unifying mechanism for the formation of the low‐relief plateau interior, and for the origin of the high‐elevation, low‐relief relict surface in southeastern Tibet. Our analysis brings forth the importance of surface processes, in particular drainage efficiency, in shaping plateau morphology and landscape relief. Such key processes appear to have been mostly ignored in numerical models of plateau deformation. Our results also cast doubt on and provide a more realistic alternative to the fashionable contention that a continuous preuplift, low‐relief surface first formed at low elevation, extending all the way to the South China Sea shore, before being warped upward in the late Miocene‐Pliocene by lower crustal channel flow.

Earthquakes from Above: Preparing for risks and hazards associated with large earthquakes requires detailed understanding of their mechanical properties. In addition to pinpointing the location and magnitude of earthquakes, postmortem analyses of the extent of rupture and amount of deformation are key quantities, but are not simply available from seismological data alone. Using a type of optical remote sensing, Light Detection and Ranging (LiDAR), Oskin et al. (p. 702 ) surveyed the surrounding area that ruptured during the 2010 M _w 7.2 El Mayor–Cucapah earthquake in Northern Mexico. Because this area had also been analyzed in 2006, a comparative analysis revealed slip rate and strain release on the shallow fault zone and a number of previously unknown faults. As remote imaging becomes cheaper and more common, differential analyses will continue to provide fault-related deformation data that complements modern seismological networks.