Seismic Deformation and Fault Mechanics in Active Regions

Seismic deformation in active tectonic regions results from the accumulation and sudden release of elastic strain on faults, manifesting as both abrupt coseismic movements and more gradual interseismic and post-seismic adjustments. Fault mechanics govern how stress is partitioned between adjacent segments, how rupture propagates through complex geometries and how energy is dissipated via frictional slip and off-fault damage. Advances in satellite geodesy, high-resolution optical correlation and three-dimensional dynamic modelling have revealed variations in slip distribution, segmentation patterns and supershear transitions. These insights, drawn from global studies of plate-boundary fault systems and intraplate structures, underpin improved seismic hazard assessments and inform resilient infrastructure design in earthquake-prone areas.

Research from Nature Portfolio

Recent studies have combined space-based geodetic observations with fully probabilistic inversion techniques to resolve the detailed three-dimensional geometry of a large strike-slip earthquake. This work demonstrates that the rupture comprised multiple irregular segments with along-strike changes in dip angle, including shallow-dipping and near-vertical branches. The findings emphasise how geometric complexities can enable significant slip on unfavourably oriented planes, and illustrate the importance of integrating geological mapping with satellite data to constrain fault segmentation and rupture propagation.

Seismic Deformation and Fault Mechanics in Active Regions publication trend

The graph below shows the total number of articles in seismic deformation and fault mechanics in active regions across all publications each year (not limited to Nature Index journals).

Technical terms

Coseismic deformation: Displacement of the Earth's surface that occurs suddenly during an earthquake.

Strike-slip fault: A fault on which the dominant displacement is horizontal and parallel to the fault trace.

Supershear rupture: A rupture that propagates at a speed exceeding the ambient shear-wave velocity of the host rock.

Segmentation: Division of a fault into discrete sections that may rupture independently or interact during seismic events.

InSAR (Interferometric Synthetic Aperture Radar): A satellite-based technique for measuring ground displacement by comparing phase differences between radar images acquired at different times.

References

1. Complex strike-slip faulting during the 2021 Mw7.4 Maduo earthquake. Communications Earth & Environment (2023).
2. Non‐Typical Supershear Rupture: Fault Heterogeneity and Segmentation Govern Unilateral Supershear and Cascading Multi‐Fault Rupture in the 2021 Mw ${M}_{w}$7.4 Maduo Earthquake. Geophysical Research Letters (2024).
3. Uniform postglacial slip-rate along the central 600 km of the Kunlun Fault (Tibet), from 26Al, 10Be, and 14C dating of riser offsets, and climatic origin of the regional morphology. Geophysical Journal International (2002).
4. Large Surface‐Rupture Gaps and Low Surface Fault Slip of the 2021 Mw 7.4 Maduo Earthquake Along a Low‐Activity Strike‐Slip Fault, Tibetan Plateau. Geophysical Research Letters (2022).