Secondary Supervisors: Dr Jessica Johnson, Dr Zoe Mildon, Dr Andreas Rietbrock
In earthquake science, a fundamental yet challenging objective is to find promising precursors that can warn people well in advance of devastating earthquakes. Recent advances in seismic and geodetic observing tools suggest transient deformation caused by processes such as slow slip accompanied by migrating seismicity may be observable weeks to months prior to large earthquakes in subduction zones. In addition, transient deformation is observed at various spatial and temporal scales following earthquakes, indicating complex stress relaxation on the fault and surrounding materials. Establishing the temporal and spatial evolution of deformation is therefore of particular importance for understanding fault behaviour before and after large earthquakes.
The project will initially study the East Kunlun fault zone in the north-eastern part of the Tibetan Plateau, focusing on the magnitude 7.4 Maduo earthquake that occurred on 22 May 2021. This earthquake is the strongest since the 2008 Sichuan earthquake and one of the most intensely felt in recent memory.
This project aims to answer questions such as:
- Is the transient deformation rate constant before the earthquake?
- How does the deformation rate vary across neighbouring faults before the earthquake?
- How does the deformation after the earthquake evolve and what is the likely process controlling the evolvement?
- How are the stresses on neighbouring faults affected by the Maduo earthquake and processes after it?
The student will apply radar interferometry (InSAR) to map surface displacement and generate deformation time series. The student will develop finite element models to explain the observations, including investigating stress relaxation mechanisms after the earthquake and stress loading on neighbouring faults.
Training will be given in InSAR data processing, finite element modelling, Coulomb stress modelling and geophysical hazard processes. The student will visit Germany (subject to restrictions) to work with Prof. Andreas Rietbrock for training on seismic methods.