There are several conflicting usages of geosphere, variously defined.
History
Aristotelian physics
In Aristotelian physics, the term was applied to four spherical
natural places, concentrically nested around the center of the Earth, as described in the lectures
Physica and
Meteorologica. They were believed to explain the motions of the four
terrestrial elements: Earth,
Water,
Air, and
Fire.
Modern era
In modern texts and in Earth system science, geosphere refers to the
Solid earth; it is used along with
atmosphere,
hydrosphere, and
biosphere to describe the systems of the Earth (the interaction of these systems with the
magnetosphere is sometimes listed). In that context, sometimes the term
lithosphere is used instead of geosphere or solid Earth. The lithosphere, however, only refers to the uppermost layers of the solid Earth (oceanic and continental crustal rocks and uppermost mantle).
[Allaby, A. and Allaby, M. (eds). (2003). A Dictionary of Earth Sciences. Oxford University Press. New York. 2nd edition. p. 320. ]
Other usages
"Geosphere" may also be taken as the collective name for the
lithosphere, the
hydrosphere, the
cryosphere, and the
atmosphere.
[Williams, R.S., Jr., and Ferrigno, J.G. (eds.) (2012) Plate Figure 4 in State of the Earth’s cryosphere at the beginning of the 21st century–Glaciers, global snow cover, floating ice, and permafrost and periglacial environments: U.S. Geological Survey Professional Paper 1386–A.] The different collectives of the geosphere are able to exchange different mass and/or energy
(the measurable amount of change). The exchange of these fluxes affects the balance of the different spheres of the geosphere. An example is how the soil acts as a part of the biosphere,
while also acting as a source of flux exchange.
Space exploration
Since space exploration began, it has been observed that the extent of the
ionosphere or
plasmasphere is highly variable, and often much larger than previously appreciated, at times extending to the boundaries of the Earth's magnetosphere.
This highly variable outer boundary of
geogenic matter has been referred to as the "geopause" (or
magnetopause),
to suggest the relative scarcity of such matter beyond it, where the
solar wind dominates.
See also
