Quaternary Sea-Level Changes
Sea-levels have changed substantially over the last two million years on both a global and a local scale, and now global warming predicts that there are likely to be significant rises in the relatively near future. Flooding caused by such changes has the potential to directly affect the lives of more than one billion people in coastal areas worldwide and with more people moving to coastal cities the situation is only going to get worse. An understanding of both the natural and anthropogenic processes that cause such changes is important in refining these predictions so that appropriate action may be taken.
Sea-levels can change by a number of different factors: the volume of water in the oceans can alter; or its temperature can rise or fall causing expansion or contraction; or there can be a change in level of the land caused by isostasy, or volcanic, seismic and tectonic forces. It’s all relative! As geologists we know that such changes have been going on throughout the history of planet Earth although until the application of scientific principles such phenomena were given mythological or religious explanations.
This review by two Australian academics into the history of research on a world-wide basis summarises the analytical methods used to interpret the variety of evidence about sea-level changes. It covers the early examples that were explained in terms of the anger of the gods and then logically and symptomatically covers the evolution of ideas that has generated our present understanding. There are also 78 pages of references - a truly magnificent collection for those engaged in research in this area!
Over the past two or three decades a series of threats to life on Earth has been revealed, showing that we do not live in a stable unchanging situation with perhaps sea-level rise being one of the most important, with its implications for moving populations and for food and water resources. There seem to be two main problems; first, there is not full agreement between scientists working in this field, particularly on the amount and timing of the changes; and second, the political systems in at least the democratic countries of the world are predicated on both short-term actions and national interest to win votes. It is hoped that this well written and readable textbook will help make a significant contribution by advancing knowledge - or am I being too optimistic?
Reviewed by Rick Brassington
Quaternary Sea-Level Changes: A Global Perspective by Colin V. Murray-Wallace & Colin D. Woodroffe 2014. Published by: Cambridge University Press 484 pp (hbk) ISBN: 978-0-521-82083-7. List price: £80.00 (US$ 125.00) www.cambridge.org