Details of Award
NERC Reference : NE/J017604/1
Effect of in-situ stress field on elastic radiation from underground explosive sources
Training Grant Award
- Lead Supervisor:
- Professor A Ziolkowski, University of Edinburgh, Sch of Geosciences
- Grant held at:
- University of Edinburgh, Sch of Geosciences
- Science Area:
- Earth
- Overall Classification:
- Earth
- ENRIs:
- Environmental Risks and Hazards
- Science Topics:
- None
- Abstract:
- The Comprehensive-Nuclear-Test-Ban Treaty (CTBT), was ratified by the United Kingdom (UK) on 6 April 1998. The Treaty bans atmospheric, underwater and underground nuclear test explosions, and has a verification regime which includes an International Monitoring System (IMS) with a network of 170 seismic, 60 infrasound, 11 hydroacoustic, and 80 particulate radionuclide stations. Currently the IMS network is about 80% complete. While primarily for verification purposes, the Treaty does not restrict the usage of IMS data for civilian and scientific applications. Recently data from IMS radionuclide stations were used to assess the fall-out from the March 2011 Fukushima reactor accident in Japan, with results presented at the Science and Technology (S&T2011) conference organised by the CTBT Organisation (CTBTO), held in Vienna 8-10 June 2011. One of the aims of S&T2011 is to build and strengthen the relations between the broader scientific community and the CTBTO. The CTBT requires a National Authority, with technical support from a National Data Centre (NDC). The NDC is recognised by the CTBTO. The UK's NDC is provided by AWE Plc undermcontract with Ministry of Defence (MoD). The UK NDC provides technical advice that aids the formulation of UK Government policy regarding security and arms control (mainly within FCO and MoD), as well as supporting the policy making organs of the CTBTO, and its Provisional Technical Secretariat (www.ctbto.org). Seismology is a significant part of the CTBT verification regime, and this NERC Open Case PhD studentship will providevaluable scientific insight into methods of identifying potential Treaty violations from naturally occurring seismic sources (mainly earthquakes), by increasing understanding of how underground explosion sources generate seismic waves. During the S&T2011, Professor Anton Ziolkowski, University of Edinburgh, presented research into the seismic sourcetime function of a chemical explosive source. The UK NDC and Professor Ziolkowski share a common interest in how explosions generate seismic waves, and it became clear during discussions that seismic data acquired during the Manitoba URL Scaled Explosion (MUSE) experiment, funded by the Canadian NDC, were of interest. The MUSE experiment was conceived as a cooperative endeavour between the Canadian and UK NDCs, and was conducted at the (Underground Research Laboratory) in 2004/2005. After consultation with the Canadian NDC it was agreed that the MUSE data set should be made available to Professor Ziolkowski to enable him to further pursue research into how explosions generate seismic waves. The MUSE data set is unique as it comprises three-component seismic recordings, from an 11 sensor network at a depth of around 420m, of signals from 22 small chemical explosions fired in granite near the surface above the network. The surface explosions were fired in two phases, in frozen and unfrozen rock, to explore possible differences in seismic coupling. One interesting result of MUSE was the observation of strong Shear (S) waves not predicted from a classical model of an isotropic explosion in an elastic medium. Observations of "break-out" in the tunnels around 400m depth indicate a stress field with principal components oriented away from the vertical and horizontal directions. This project seeks to analyse the recordings of primary (P) and S waves from MUSE, develop a model to predict the effect of in situ stress on the generation of seismic waves from underground explosion sources, and apply this model to the MUSE data. The output from the PhD project will help the UK NDC assess whether in situ stress is a physical factor in the generation of S waves observed from underground explosions, and the potential impact on methods developed to identify underground explosions from earthquakes based on empirical observations of P/S amplitude ratios. The P/S ratio method is proposed as part of the CTBT verification regime,
- NERC Reference:
- NE/J017604/1
- Grant Stage:
- Completed
- Scheme:
- DTG - directed
- Grant Status:
- Closed
- Programme:
- Open CASE
This training grant award has a total value of £67,596
FDAB - Financial Details (Award breakdown by headings)
| Total - Fees | Total - RTSG | Total - Student Stipend |
|---|---|---|
| £13,812 | £5,500 | £48,285 |
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