Active Tectonics of Strike-slip Restraining & Releasing Bends

This exciting project aims to advance our understanding of active crustal deformation and continental tectonics for a number of major strike-slip fault zones using high resolution satellite SAR interferometry. In particular, we aim to quantify rates of uplift and subsidence associated with restraining and releasing bends using the latest earth observation techniques.

This project will use novel space-based instruments (Elliott et al, 2016) and develop quantitative methodologies to assess active tectonic rates of deformation associated with restraining and releasing bends of major continental strike-slip faults. Determining the rate of deformation in these zones is especially important for understanding the tectonics of these active structures and the role they play in generating major topographic relief, in additional to accommodating the overall strike-slip motion between crustal blocks. The aim is to identify the relative rates and activity of push up ridges and pull apart basins, as these are major tectonic features visible across deforming continental interiors (Cunningham & Mann, 2007). Initially the project will explore strike-slip zones in Central Asia, focusing on major strike slip zones such as the Altyn Tagh Fault along the northern margin of the Tibetan plateau (Figure 1). This builds on a recent study recently completed in this area examining the strain accumulation across this major fault (Shen et al., 2019). Further parts of this strike-slip zone will also be analysed, as well as other major strike-slip faults in the region.

Objectives
In this project, the student will apply the latest techniques in measuring active tectonics, faulting, continental deformation and mountain building. The project will have the following specific objectives:

  1. The postgraduate researcher will generate high resolution synthetic aperture radar (SAR) satellite data from Sentinel-1 over restraining and releasing bends of the Altyn Tagh strike-slip zones in Central Asia (Lazecky et al., 2020). This will involve using data from multiple look directions to help constrain the vertical component of deformation.
  2. They will then generate dense time series of deformation across these fault bends to quantify the rates of uplift and subsidence associated with strain accumulation on these structures (Morishita et al., 2020), accounting for any seasonal signal noise that will mask these rates as well as implementing atmospheric noise corrections.
  3. From this data they will then model the deformation on the bounding fault structures using numerical finite element software to identify the key active structures responsible for controlling the uplift and subsidence. They will also attempt to correlate this with the existing extent of topography, and any known rates of long-term uplift.
  4. They will subsequently apply this approach to a selection of other major strike-slip faults that are rapidly deforming across the continents to quantify rates of uplift and subsidence associated with these structures, as well as constrain the styles of deformation (Cunningham & Mann, 2007).

The balance between these components will vary depending on the specific interests of the student.

Training
The student will work under the supervision of Dr. John Elliott, within the Active Tectonics group of the Institute of Geophysics & Tectonics in the School of Earth & Environment at Leeds. The project will be co-supervised by Prof. Tim Wright (also in IGT, SEE). The Institute of Geophysics & Tectonics also hosts the Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics (COMET http://comet.nerc.ac.uk/) which provides a large group of researchers engaged in active tectonics research with whom the student can interact. The successful PhD student will have access to a broad spectrum of training workshops that include an extensive range from scientific computing through to managing your degree, to preparing for your viva (http://www.emeskillstraining.leeds.ac.uk/). The student will also have the opportunity to engage with a wider range of scientists within COMET at a number of other UK institutions who have a broad interest in problems of active tectonics.

Student profile
The student should have a strong interest in remote sensing, active tectonics problems, and a strong background in a quantitative science (earth sciences, geophysics, geology, physics, natural sciences). Ability to work with programming languages (such as Matlab and Python) as well as within a GIS framework and experience of large datasets (such as earth Observation imagery) would be useful.

References
Cunningham, W. D., & Mann, P. (2007)
Tectonics of strike-slip restraining and releasing bends. Geological Society, London, Special Publications, 290(1), 1-12, doi:10.1144/SP290.1.

Elliott, J. R., R. J. Walters & T. J. Wright (2016)
The role of space-based observation in understanding and responding to active tectonics and earthquakes, Nature Communications, 7, doi:10.1038/ncomms13844.

Lazecký, M., Spaans, K., González, P.J., Maghsoudi, Y., Morishita, Y., Albino, F., Elliott, J., Greenall, N., Hatton, E., Hooper, A., Juncu, D., McDougall., A., Walters, R. J., Watson, C. S., Weiss, J. & Wright, T. J.  (2020)
LiCSAR: An automatic InSAR tool for measuring and monitoring tectonic and volcanic activity. Remote Sensing, 12(15), p.2430, doi:10.3390/rs12152430.

Morishita, Y., Lazecky, M., Wright, T.J., Weiss, J.R., Elliott, J.R. and Hooper, A. (2020)
LiCSBAS: An Open-Source InSAR Time Series Analysis Package Integrated with the LiCSAR Automated Sentinel-1 InSAR Processor. Remote Sensing, 12(3), p.424, doi:10.3390/rs12030424.

Shen, L., Hooper, A. and Elliott, J. R. (2019)
A Spatially Varying Scaling Method for InSAR Tropospheric Corrections Using a High‐Resolution Weather Model. Journal of Geophysical Research: Solid Earth, 124(4), pp.4051-4068, doi:10.1029/2018JB016189.