Orogen-scale uplift in the central Italian Apennines drives episodic behaviour of earthquake faults

Cowie, P.A. et al. (2017) Orogen-scale uplift in the central Italian Apennines drives episodic behaviour of earthquake faults. Scientific Reports, 7, 44858. (doi: 10.1038/srep44858) (PMID:28322311) (PMCID:PMC5359594)

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Abstract

Many areas of the Earth’s crust deform by distributed extensional faulting and complex fault interactions are often observed. Geodetic data generally indicate a simpler picture of continuum deformation over decades but relating this behaviour to earthquake occurrence over centuries, given numerous potentially active faults, remains a global problem in hazard assessment. We address this challenge for an array of seismogenic faults in the central Italian Apennines, where crustal extension and devastating earthquakes occur in response to regional surface uplift. We constrain fault slip-rates since ~18 ka using variations in cosmogenic 36Cl measured on bedrock scarps, mapped using LiDAR and ground penetrating radar, and compare these rates to those inferred from geodesy. The 36Cl data reveal that individual faults typically accumulate meters of displacement relatively rapidly over several thousand years, separated by similar length time intervals when slip-rates are much lower, and activity shifts between faults across strike. Our rates agree with continuum deformation rates when averaged over long spatial or temporal scales (104 yr; 102 km) but over shorter timescales most of the deformation may be accommodated by <30% of the across-strike fault array. We attribute the shifts in activity to temporal variations in the mechanical work of faulting.

Item Type:Articles
Additional Information:This work was supported by NERC grants: NER/S/A/2006/14042, NE/E01545X/1, NE/E016545/1, NE/I026715/1, NE/I024127/1 and NE/I02318X/1.
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Wilcken, Mr Klaus and Shanks, Dr Richard and Freeman, Professor Stewart
Authors: Cowie, P.A., Phillips, R.J., Roberts, G.P., McCaffrey, K., Zijerveld, L.J.J., Gregory, L.C., Faure Walker, J., Wedmore, L.N.J., Dunai, T.J., Binnie, S.A., Freeman, S.P.H.T., Wilcken, K., Shanks, R.P., Huismans, R.S., Papanikolaou, I., Michetti, A.M., and Wilkinson, M.
College/School:College of Science and Engineering > Scottish Universities Environmental Research Centre
Journal Name:Scientific Reports
Publisher:Nature Publishing Group
ISSN:2045-2322
ISSN (Online):2045-2322
Copyright Holders:Copyright © 2017 The Authors
First Published:First published in Scientific Reports 7:44858
Publisher Policy:Reproduced under a Creative Commons License

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
NE/I02318X/1