- Correspondence to Dr William E Stephens, School of Earth & Environmental Sciences, University of St Andrews, Irvine Building, North Street, St Andrews, Fife KY16 9AL, Scotland, UK;
- Received 24 April 2017
- Revised 18 July 2017
- Accepted 18 July 2017
- Published in print 1 January 2018.
- Published online 18 December 2017.
- Published first 4 August 2017.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.