Offshore seismic hazard models and maps for the UK Exclusive Economic Zone

A new, robust seismic hazard model and seismic hazard maps for the UK offshore Exclusive Economic Zone using the latest available data and recent advances in seismic hazard methodology and a Monte Carlo-based approach for probabilistic seismic hazard analysis. These are intended to update the current maps for UK waters published in 2002. We developed a comprehensive catalogue of earthquake activity across the region by combining existing earthquake catalogues and data from regional and local monitoring agencies. We modelled earthquake occurrence across the region using a seismic source characterisation (SSC) model that consists of a series of zones, where seismicity is considered to be homogeneous, based on tectonics, geology and seismicity of the study area. We use four different seismic source zone models within the SSC to capture the epistemic uncertainty in different rupture scenarios. A logic tree approach was used to account for the epistemic uncertainty in earthquake activity rates, maximum magnitude, earthquake depth distribution, and faulting style. Ground motions are estimated for different rupture scenarios using a ground motion characterisation (GMC) model that consists of five multiple ground motion prediction equations considered to be applicable to the region. The GMPEs are included in a logic tree where the weights are informed by the fit between observed and modelled ground motions. The GMC model also includes the host-to-target adjustments and a single-station sigma model. Hazard is calculated at 4585 individual points spaced at 0.125° in latitude and 0.25° in longitude for peak ground acceleration (PGA) and spectral acceleration at 0.2 s (SA0.2 s) and 1.0 s (SA1.0 s) for 5% damping and rock conditions and the return periods of 95, 475, 1100, 2475, and 5000 years. This is the first time that maps of the seismic hazard at short (0.2 s) and long periods (1.0 s) have been produced for UK waters. Hazard curves, uniform hazard spectra, and disaggregation analysis have been calculated for three offshore carbon capture and storage sites (Endurance, Acorn, and HyNet North West). New offshore hazard maps for the UK waters will support UK decarbonisation by providing owners and operators of offshore structures with robust estimates of seismic hazard for new and existing sites. The results will also inform regulatory decisions to ensure safe operating practices in the industry and help identify areas of higher hazard where further site-specific studies might be needed. Finally, it will provide a robust baseline for tectonic seismic activity in the North Sea that can be used to help discriminate any seismicity induced by operations, such as CCS, in the event it occurs. The technical report by Mosca et al. (2024), which provides a detailed description of the methods and results, together with the project’s products, can be found in ( http://www.earthquakes.bgs.ac.uk/hazard/UKhazard.html).

Date (Creation): 2025-07-21

Citation identifier: http://data.bgs.ac.uk/id/dataHolding/13608537

Point of contact

Organisation name	Individual name	Electronic mail address	Role
British Geological Survey	Enquiries	enquiries@bgs.ac.uk	Distributor
British Geological Survey	Enquiries	enquiries@bgs.ac.uk	Originator
British Geological Survey	Enquiries	enquiries@bgs.ac.uk	Distributor
British Geological Survey	Enquiries	enquiries@bgs.ac.uk	Point of contact
British Geological Survey	Enquiries	enquiries@bgs.ac.uk	Originator
British Geological Survey	Enquiries	not available	Distributor
British Geological Survey	Enquiries	not available	Point of contact

Maintenance and update frequency: notApplicable

GEMET - INSPIRE themes, version 1.0

Geology

BGS Thesaurus of Geosciences

Seismicity
NGDC Deposited Data
Citable Data
MEDIN
Earthquakes
Simulation
Models
Natural hazards

dataCentre

Keywords

NERC_DDC

Access constraints: Other restrictions

Other constraints: licenceOGL

Other constraints: Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]"

Use constraints: Other restrictions

Other constraints: The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused.

Other constraints: Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]"

Spatial representation type: Vector

Language: English

Topic category

Geoscientific information

Geographic identifier: UK CONTINENTAL SHELF [id=121701]
British Geological Survey Gazetteer: Geographical hierarchy from Geosaurus 1979 creation

Begin date: 2023-03-01

End date: 2025-01-23

Unique resource identifier: WGS 84 (EPSG::4326)

Distribution format

Name	Version
txt
csv

Distributor contact

Organisation name	Individual name	Electronic mail address	Role
British Geological Survey	Enquiries	enquiries@bgs.ac.uk	Distributor

Distributor contact

Organisation name	Individual name	Electronic mail address	Role
British Geological Survey	Enquiries	enquiries@bgs.ac.uk	Distributor

Distributor contact

Organisation name	Individual name	Electronic mail address	Role
British Geological Survey	Enquiries	not available	Distributor

OnLine resource

Protocol	Linkage	Name
	https://webapps.bgs.ac.uk/services/ngdc/accessions/index.html#item189080	Data

OnLine resource

Protocol	Linkage	Name
	https://doi.org/10.5285/a6babafa-5c82-4e76-aef5-27441104187f	Digital Object Identifier (DOI)

Hierarchy level: Dataset

Other: dataset

Conformance result

Title: INSPIRE Implementing rules laying down technical arrangements for the interoperability and harmonisation of Geology

Date (Publication): 2011

Explanation: See the referenced specification

Pass: No

Conformance result

Title: Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services

Date (Publication): 2010-12-08

Explanation: See http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:323:0011:0102:EN:PDF

Pass: No

Statement: We use probabilistic seismic hazard analysis (PSHA), which combines seismological, geological and geophysical data to produce a probabilistic description of expected ground shaking that may occur at a site. This consists of four steps: 1) Definition of seismic sources based on the tectonics, geology and seismicity in the region, forming a seismic source model (SSM). 2) Quantification of the rate of earthquake occurrence for each seismic source using the Gutenberg-Richter law. 3) Characterisation of the ‘earthquake effect’. 4) Estimation of the hazard at the site(s) by integrating over the seismic sources for the location and size of future earthquakes with expected ground shaking. We used Monte Carlo-based PSHA to generate artificial catalogues by random sampling of the probability distributions in the SSM and computing the predicted ground motion for the synthetic events.