Water and sediment movement around a coastal headland: Portland Bill,southern UK

Numerical simulations of tidal flow and sand transport around a coastal headland (Portland Bill, southern UK) were undertaken to investigate patterns of sand transport during the development of tidally induced transient eddies. Results obtained from a 2-D finite-element hydrodynamic model (TELEMAC-2D) were combined with a sediment transport model (SEDTRANS), to simulate the sand transport processes around the headland. Simulation of the tidal flow around Portland Bill has shown the formation and evolution of tidally induced transient eddies, around the headland. During the evolution of these transient eddies, no current-induced bedload (transport) eddy is formed for either side of the headland. Net bedload sand transport direction, around a coastal headland, is the result of instantaneous gradients in bedload transport rates, during flood and ebb flows, rather than the average (residual) flow. Thus, the use of residual (water) circulation to describe patterns of sediment movement as bedload is not an appropriatedapproach. In the case study presented here, the distinct characteristics of the coastal and seabed morphology around the Isle of Portland (i.e. headland shape and the bathymetry) indicate that these parameters can be influencing tidal (flow) and sediment dispersion around the headland. Such an interpretation has broader implications and applications to headland-associated sandbanks elsewhere.Responsible Editor: Hans Burchard     

Converting science to policy through stakeholder involvement: an analysis of the European Marine Strategy Directive

The Marine Strategy Directive requires European Union Member States to develop science-based marine strategies with the involvement of stakeholders, in order that Europe’s marine environment reaches ‘good environmental status’ by 2021. The scientific requirements of marine strategies are clearly defined within the Directive, however, the requirements related to stakeholder involvement are not. This paper presents a critical analysis of the provisions for stakeholder involvement with in the Marine Strategy Directive. In particular, the paper is focused upon the definition of stakeholder, the sequencing of involvement, and the form and purpose of involvement. The critique is set within an evaluative framework that considers policy-making to be a social process, rather than a purely scientific one. It is concluded that the Marine Strategy Directive lacks coherency with respect to stakeholder involvement which may perpetuate the traditional tension between marine science and policy. This in turn may compromise the ability of the Directive to protect Europe’s marine environment.     

Astrobiology in the UK

Mark Burchell and Lewis Dartnell review the current standing of astrobiology research in the UK, and look to future success.     

UK in the Aurora Programme

John Bridges surveys the scope of UK planetary science and technology, and the prospects for scientific, technical and commercial gains that could result from our participation in the Aurora Programme.     

Marine terraces

Summary The theory of the formation of marine terraces is studied. A model is set up which is believed to describe the physical processes involved. This model leads to a nonlinear partial differential equation which is integrated for some special cases by means of a digital computer. Asymptotic solutions of the differential equation are also found by direct analytical means. It is found that no terraces can develop if eustatic changes occur at a constant rate, contrary to some contentions that have been advanced in the literature.     

海洋地球物理导航

本文分析了海洋地球物理导航在水下航行器应用研发中的重要价值,总结了地球物理导航的理论方法,指出了海洋地球物理导航中有待解决的关键技术问题及其发展方向,阐明了海洋地球物理导航与惯导系统的组合是实现实时、连续、精确、安全隐蔽、完全自主水下导航的理想途径.