Robertson, Jennifer (2021) Investigation of the deformation rates implied by marine terraces to determine fault slip rates over multiple seismic cycles. PhD thesis, Birkbeck, University of London.
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Abstract
Deformation caused by earthquakes is accommodated along faults over multiple seismic cycles, yet our understanding of fault behaviour is based upon short-term observations over a few thousands of years. This is problematic because some faults have been known to exhibit episodic behaviour, whereby they do not rupture in a time-averaged manner. Thus, it is unclear whether short-term fault observations are representative of fault behaviour over hundreds of thousands of years. This issue confounds our ability to undertake effective seismic hazard assessment, which is vital for population centres and critical facilities located in the vicinity of active faults. Studies on late Quaternary palaeoshorelines that are deformed due to upper-plate and subduction-related faulting have been successfully used to interrogate long-term fault behaviour and derive slip and throw rates of faults that are representative of multiple seismic cycles. However, such studies maybe limited by a lack of age constraints, by the approach used to correlate undated palaeoshorelines to sea-level highstands and by uncertainties associated with sea-level elevations of Late-Quaternary highstands. This thesis employs a new approach to investigate the long-term behaviour of upper-plate extensional faults using deformed palaeoshorelines. Investigations are focused upon palaeoshorelines in Crete, adjacent to the western Hellenic subduction zone, and within the Gulf of Corinth intracontinental rift. The results presented in this thesis demonstrate that 36Cl exposure dating is an acceptable dating method on carbonate wave-cut platforms and that corals with elevated δ234U, usually suggestive of post-depositional diagenesis, can provide reliable palaeoshoreline ages. Synchronous correlation of undated palaeoshorelines to sea-level highstands alongside elastic half-space dislocation modelling allows valuable insights into the dominant tectonic controls of palaeoshoreline deformation. The findings presented herein emphasise that upper-plate extensional faults have the capacity to perturb coastline deformation and that observations associated with this deformation can provide insights that are essential for seismic hazard assessment.
Metadata
Item Type: | Thesis |
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Copyright Holders: | The copyright of this thesis rests with the author, who asserts his/her right to be known as such according to the Copyright Designs and Patents Act 1988. No dealing with the thesis contrary to the copyright or moral rights of the author is permitted. |
Depositing User: | Acquisitions And Metadata |
Date Deposited: | 14 Sep 2021 11:37 |
Last Modified: | 01 Nov 2023 14:43 |
URI: | https://eprints.bbk.ac.uk/id/eprint/45972 |
DOI: | https://doi.org/10.18743/PUB.00045972 |
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