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Pingos, palsas and eskers are among the landforms described and explained
in this beautifully illustrated book, Natural Landscapes of Britain From
the Air (Cambridge University Press, pp 288, £19.50). Nicholas Stephens,
the editor, has pulled together clear aerial photographs of a range of Britain’s
landscapes, showing how ice and water shape the land. Striking black and
white pictures and careful use of diagrams bring clarity to a fascinating
subject, and answer many of those niggling questions that plague the traveller.
Among my questions answered is how to spot a pingo-these are the remains
of hummocks a few metres across, raised by ice building up below the soil.
Palsas form in much the same way, but in peat. And eskers? These snakey
ridges are sediment dumped by the streams that carried water away from the
melting glaciers. This is more than just a picture book. It is mine of information
and useful examples-what asymmetrical dry valleys mean, for example. The
book begins with a brief geological history of Britain, full of examples
of the landscapes that result from different stages in this billion year
evolution. Next come glacial landscapes from Snowdonia and the Scottish
Highlands, coastlines and river valleys galore. It ends with landscapes
that are changing now, through tourism, flood defences and quarrying.