Sea-Level Research

An editorial by Wanless (1982), entitled "Sea level is rising - so what?", tells the case of an executive editor of a major city newspaper, who, when confronted with evi­ dence for a recent sea-level rise, replied: "That just means the ocean is six inches deeper, doesn't it?". Whether his "so what?" attitude was real or put on to dike a threat of sensation, there is at present a wide and deepening interest in ongoing and future global sea-level change. This interest has grown along with the concern over global warming due to increasing levels of C02 and trace gases. A stage has been reached where investigators of climat- sea-level relationships call for long-term measurement programmes for ice-volume changes (using satellite altimetry) and changes in temperature and salinity of the oceans (ther­ mal expansion). This manual, however, is primarily concerned with sea­ level changes in the past, mainly since the end of the last glaciation. Its major objective is to help answer the ques­ tion: "how?", which, of course, is little else but to assist in the gathering of fuel for the burning question: "why?" Good fuel, hopefully, for the less smoke and ashes, and the more heat and light produced by that fire, the better scientists are enabled to develop a quantitative under­ standing of past, and hence of future, sea-level changes on different spatial and temporal scales.