The climatic record in polar ice sheets

Title :- The climatic record in polar ice sheets

Edited By :- Gordon de Q. Robin

Published :- Cambridge University Press – hardback, London, New York, Sydney  1983 (200 pages – large format)

Outline :- Workshop papers and some subsequent modeling based around the Scott Polar Research Institute 1973 and other international studies. The book is very technical with easy to understand conclusions at the end of each chapter. Being a scientific publication (including many formulae, levels of accuracy etc) it starts with a description of Greenland and Antarctica, then proceeds with review of theory of snow trapping air and the isotope linkage to the environment (altitude & temperature), and the deposition mechanisms for snow. The book continues with sampling descriptions and interpretation of ice flow morphology influences. A steady state model of surface to base temperature profiles is determined and tested against recorded data from numerous sites in Greenland & Antarctica. The book identifies a number of warmer & cooler periods, and identifies the last ice age.

It is interesting to note that :-

• The internal stress of the ice sheet plays a roll in developing ice shear faults that can lead to “repeated drill sections” etc.
• The top of the ice sheet is typically – 25 degrees while the bas is typically at 0 degrees (due to the earth’s heat) allowing the bottom few meters of ice to be semi liquid, and contain mixed layers of glacial till / rock.
• The dynamics of the ice when it leaves the earth floor and floats out over the ocean is interesting.
• Much of North America is still uprising as a result of isostatic rising from the last ice age of around 100,000 years ago, and may continue rising for another 300 years.
• The top portion of the surface has yet to consolidate, and thus recordings from this age are less reliable. The deposition of snow (and thus record of climate) is not even over the ice caps, and can vary over short distances (like scour & fill in sediment records).

This is essential reading for those who wish to understand or participate in the climate debate.

The book refers to fine volcanic ash layers – a review of the frequency and character of such may stimulate further research into the role of volcanoes on climate.