Geoscience Reference
In-Depth Information
KEY POINTS
1
Aeolian processes are dependent on suitable airflow conditions and the provision of fine-grained products
of other geomorphic processes. Wind deflates, i.e. entrains, removes and eventually deposits, these
materials as metastable aeolian landforms. Armed with the abrasive tools, air flow also scours bedrock
surfaces in its path.
2
Aeolian landforms are found primarily in areas of atmospheric subsidence and associated hot and cold
arid zones, rather than in storm belts. Lack of protective vegetation increases effective wind velocity in
areas of lower absolute velocity and exposes Earth materials to desiccation and deflation.
3
Tectonic processes exert background controls through uplift, basin formation and the creation of rain
shadow. Upwelling cold ocean currents suppress rainfall and enhance aridity on adjacent coasts.
4
Residual abraded rock surfaces, supporting lag gravels or scoured into yardangs, and ergs or sand seas
with dune and ripple bed forms at all scales, form the aeolian landsystems of hot deserts. Loess sheets
derived from glacial and frost desert processes represent cool/cold desert deflation products, especially
beyond the former margins of Pleistocene ice sheets.
5
Aeolian processes are not restricted to arid climate zones. Physiological drought and the availability of
dry, fine-grained materials in coastal, mountain, urban and arable farming environments all promote more
localized aeolian activity. Mid-latitude land surfaces may become increasingly vulnerable to aeolian
processes as a result of global warming and its feedbacks.
FURTHER READING
Goudie, A. S. (2002), Great Warm Deserts of the World: landscapes and evolution, Oxford: Oxford University Press. An
excellent compendium of the climatic background and geomorphological processes and landforms of Earth's hot deserts,
by region.
Goudie, A. S., Livingstone, I. and Stokes, S. (1999) Aeolian Environments: processes and landforms, Chichester and New
York: Wiley. A compilation of work by authors who have previously published on aeolian subjects, which spans the full
range of aeolian geomorphology. It commences with an historical perspective and concludes with the Quaternary context
and predictions of future changes in the environment, all well illustrated graphically and with case studies.
Lancaster, N. (1995) Geomorphology of Desert Dunes, London and New York: Routledge. Sand dunes are the most
widespread and evocative form of aeolian deposit, and this topic focuses on dune processes, landforms and
environments. The text is not unduly technical in style and is well illustrated.
WEB RESOURCES
http://www.desertusa.com/life.html A
n excellent and well illustrated website of the south-west deserts of the United
States, ranging over their geological, geomorphological, climate, biosphere, peoples and cultural aspects. The site also
runs a free newsletter and is a good source for images and videos of desert environments and alife.
http://pubs.usgs.gov/gip/deserts/contents/ P
art of the US Geological Survey website which, although not recently
maintained, provides comprehensive cover of desert climate, environments, processes, landsystems and further
resources.
http://www.unccd.int/main.php T
he website of the United Nations Convention to Combat Desertification provides an
opportunity to look at dryland and desert areas from a wider and more applied perspective than that of desert
geomorphology but there are useful connections between both interests. The website provides access to scientific,
socio-economic, management and policy aspects of desertification across the world.
