School of Earth and Environment

Institute of Geophysics and Tectonics (IGT) PhD Projects

Measuring and modeling large scale deformation in Tibet

Supervisors: Tim Wright, Greg Houseman (Leeds), Hua Wang (Guandong University of Technology)

The Tibetan plateau is the largest deforming area on the planet, created by the collision of the Indian plate with Eurasia. Deformation and elevated topography spans an area of more than 1000 km from the Himalayan front to the Tarim basin. Despite 30 years of intensive study, the modes of deformation within the Tibetan plateau remain controversial. In particular, the role of major faults in accommodating strain within the plateau interior is unclear. Crustal deformation can be measured using repeated GPS measurements, but data is very sparse, particularly in central and western Tibet, where field access is very difficult. In recent years, synthetic aperture radar interfeormetry (InSAR) has been used to measure crustal deformation around locked faults, and hence to provide estimates of the slip rates on those faults. The results have shown that the major faults are not accumulating strain at the high rates suggested by some geological estimates (Wright et al., 2004; Elliott et al, 2009). We have recently developed methods that allow us to combine results from multiple radar tracks to build up strain maps of very large areas. The aim of the project is to apply and test these methods by analysing InSAR data from a large area in western and central Tibet (Figure 1). The results will be used to test numerical models of the Indo­Asian collision.

Figure 1: Topography of Western Tibet showing InSAR tracks (blue boxes), GPS vectors (green arrows), and major faults (red lines)

Specifically the student will:

  1. Process InSAR data acquired by the Envisat satellite in the framework of the joint ESA-NSCC dragon project. This will include data in image mode and wide swath.
  2. Combine the data sets with the available GPS data into a large-scale velocity field by building on the methods recently developed at Leeds.
  3. Conduct a robust and careful analysis of the noise contributions in the InSAR data, using wavelet methods.
  4. Test numerical models of crustal deformation for the Tibetan plateau developed in Leeds.
  5. Be involved in the analysis of any major earthquakes that occur in the study region.

The studentship would suit a numerate earth scientist or physical scientist. The student will be trained in the processing of InSAR data and a suite of remote sensing and data analysis tools. They will be part of the National Centre for Earth Observation (dynamic earth theme – COMET+), and attend regular NCEO meetings.

Further Reading

  • Wang, H; Wright, TJ; Biggs, J (2009) Interseismic slip rate of the northwestern Xianshuihe fault from InSAR data, GEOPHYS RES LETT, 36,. doi:10. 1029/2008GL036560 
  • Elliott, JR; Biggs, J; Parsons, B; Wright, TJ (2008) InSAR slip rate determination on the Altyn Tagh Fault, northern Tibet, in the presence of topographically correlated atmospheric delays, GEOPHYS RES LETT,35(12), . doi:10.1029/2008GL033659 
  • Wright, TJ; Parsons, B; England, PC; Fielding, EJ (2004) InSAR observations of low slip rates on the major faults of western Tibet, SCIENCE, 305(5681), pp236-239.