Rift fault activity and interaction at high resolution using geophysical and drilling data analysis from Greece and East Africa

Project Rationale:
Active continental rifts and the faults that control their deformation are the source of earthquakes and create some of our most important sediment sinks. Corinth (Greece) and East Africa (e.g., Tanganyika) are two of the most active, rapdily extending continental rift zones on Earth, globally recognised for their significance in the initiation of the process of new ocean basin formation1,2. This project will integrate marine seismic and earthquake data, with new ocean drilling core and log data sampling rift sediments (Corinth rift: ocean drilling completed 20172) and field and earthquake data to study how faults grow, overlap and interact in active rift systems3. It is rare to be able to study how individual faults interact at the temporal and spatial scale relevant to a few earthquake cycles in an active and high-rate tectonic system, but these new combined datasets of fault displacement history, age and slip rate will provide a very high resolution record of fault activity. Fault control on sediment accumulation and fault development and activity are important for hydrocarbon systems. Active rift zones also generate damaging earthquakes and, in some cases, tsunamis: therefore fault slip change through time and fault interaction are important for hazard analysis.

Methodology:
The project will use different combinations of datasets at two rifts. In Corinth, new drilling data will provide high resolution ages of the rift basin sediments, displaced by active faults. These ages will be integrated with existing and new marine geophysical data (multibeam, high-frequency seismic reflection) to study the history and interaction of particular rift fault systems in very great detail: fault slip history can be generated at 10’s m vertical scale and temporal scales of ~1000’s years (a few earthquake cycles). New or available marine geophysical data imaging fault displacement and history may also be used from East Africa. At both rifts, the student will analyse onshore fault extensions in the form of fault and geomorphic mapping, and local network earthquake data will be used to assess fault activity and interplay. The datasets will be integrated for the time-history of individual fault slip and how proximity of other developing faults affects the activity of an individual rift fault. The two young rift systems contrast – one extending at very high rate but without volcanism (Corinth) and one with faulting and magmatism accommodating extension (East Africa). Therefore comparing results from the two rifts will show if rifting style affects fault behaviour.

Training :
The INSPIRE DTP programme provides comprehensive personal and professional development training alongside extensive opportunities for students to expand their multi-disciplinary outlook through interactions with a wide network of academic, research and industrial/policy partners. The student will be registered at the University of Southampton and hosted at [INSERT HOST ORGANISATION/DEPARTMENT]. Specific training will
include:
Training in analysis of sediment core and log data from ocean drilling Expedition 381, Corinth Rift.
Training in acquisition, processing and analysis of high-resolution marine geophysical datasets (multibeam bathymetry, seismic reflection) and analysis of earthquake data. The Geology and Geophysics Research Group have exceptional marine geophysical facilities, including marine equipment and state-of-the-art computer hardware and software for analysis.
Software instruction through formal training sessions; training in the use of marine equipment and onshore active fault analysis in the field.
Training in the analysis of fault slip, extension rates, dating techniques, rift development and role of magmatic intrusion.