1192 S. Tooth
Copyright © 2006 John Wiley & Sons, Ltd. Earth Surf. Process. Landforms 31, 1192–1194 (2006)
DOI: 10.1002/esp
Earth Surface Processes and Landforms
Earth Surf. Process. Landforms 31, 1192–1194 (2006)
Published online 30 May 2006 in Wiley InterScience
(www.interscience.wiley.com) DOI: 10.1002/esp.1383
ESEX Commentary
Virtual globes: a catalyst for the re-enchantment
of geomorphology?
Stephen Tooth*
River Basin Dynamics and Hydrology Research Group, Institute of Geography and Earth Sciences, University of Wales, Aberystwyth, SY23
3DB, UK
Received 6 March 2006; Revised 19 March 2006; Accepted 27 March 2006
*Correspondence to: S. Tooth, River Basin Dynamics and Hydrology Research Group, Institute of Geography and Earth Sciences, University
of Wales, Aberystwyth, SY23 3DB, UK. Email: set@aber.ac.uk
Baker and Twidale (1991) bemoaned a perceived loss of enchantment from the discipline of geomorphology, arguing
that practical and philosophical impediments were thwarting attempts to achieve a satisfying understanding of landforms
and their genesis. Other concerns for the status and future of the discipline have been voiced subsequently, most
recently in this forum (e.g. Church, 2005; Summerfield, 2005a), and have highlighted challenges such as the relation-
ship of geomorphology to cognate disciplines, difficulties in reconciling teaching and research needs, the balance
between pure and applied studies, and the undertaking of landscape studies by researchers from outside the traditional
geomorphological community. The purpose of this commentary is not to deny these challenges but to echo Summerfield’s
(2005a) cautiously upbeat tone, by proposing that a more positive development is the recent launch of virtual globes
that vastly increase the availability of digital imagery of the Earth’s surface, and thus provide an opportunity for the
re-enchantment of geomorphology.
Virtual Globes
Virtual globes such as Google Earth and NASA’s World Wind combine topographic representations of the Earth’s
surface with satellite imagery. Using simple controls, one can zoom from altitude to any natural or urban area, and
using a combination of zoom, pan and tilt, examine the terrain at different scales from vertical or oblique, three-
dimensional (3D), perspectives. Google Earth has one layer of relatively recent (last three years) satellite imagery
stitched together from a variety of commercial sources, whilst World Wind has multiple layers of satellite imagery
(e.g. LandSat 7, SRTM, MODIS), as well as topographic maps for the United States. Both programs have higher
resolution imagery for some cities and areas of North America and western Europe. Images are fully georeferenced,
with options to display relevant coordinates, spot elevations and place names. These facilities have long been available
in expensive GIS software packages, but the basic versions of virtual globes are available free on the Internet, can be
downloaded and installed in a few minutes, and will run smoothly on most modern computers with a fast internet
connection. Thus, with minimal technical ability and a few mouse clicks, virtual globes can bring the varied
geomorphology of Earth into one’s office or home, and associated animations and overlays can be used to visualize
landscape-scale events such as hurricanes, wildfires, floods and dust storms. Virtual globes for other planetary bodies
such as the Moon and Mars are available as add-ons for World Wind, and interactive image mosaics are also available
via Google Mars and Google Moon. Unsurprisingly, virtual globes have been capturing the imagination of scientists
and laypeople alike; in its first week on the web (late summer 2004), 100 000 users downloaded World Wind (NASA,
2004), and millions more have downloaded virtual globes since. World Wind is an open source program, enabling
users to contribute their own modifications, and Google Earth allows user modification within certain pre-defined
parameters. As reported in Nature (Butler, 2006; Nourbakhsh, 2006), researchers in other disciplines have already
seized upon the potential of virtual globes to display a variety of spatial data in order to enhance basic scientific and
applied work. No doubt many geomorphologists have also considered the possibilities; indeed, when a colleague