Chapter 2
The Habitats
One of the attractions of the research on extreme environments is that it
must, by necessity, involve study of natural environments. Thus, the work
immediately becomes habitat-orientated or geographic. This appeals to
many, as they imagine the glamour of traveling to exotic places. And it is
a
strange thing that good geothermal areas are, to a great extent, situated
in
exciting locales. This indeed adds a certain attraction to the work, but
one
soon becomes immersed in the microscope or the Teflon homogenizer, and
the excitement palls. When I tried to publish a picture of a light-reduction
setup in a Yellowstone hot spring (Figure 10.5), one of the reviewers for
the
Journal of Bacteriology demanded that the picture be removed, as all it
would do would be to elicit envy in the reader. A strange reason! (The
picture stayed in.)
Origins of Thermal Environments
There are four distinct causes of thermal environments: solar heating,
combustion processes, radioactive decay, and geothermal activity. In man-
influenced environments, most heating is due to combustion processes, but
recently heat production as a result of radioactivity has become of signifi-
cance and interest.
Solar Heating
Solar heating can lead to soil temperatures as high as 60TC. Schramm (1966)
measured temperatures of this magnitude on black anthracite wastes in
eastern Pennsylvania. Although such high temperatures occur only during