Australia: The Land Where Time Began |
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Mountain
Uplift and Global Cooling
The topography of
the Earth is the result of the interplay of many processes, some of
which originate inside the earth, some outside
the Earth and some on the earth. Mountain uplifting over the last 40
million years has been a very active process, the Tibetan Plateau having
risen by up to 4,000 m, of which 2,000 m has occurred in the last 10
million years. In the US ⅔ of the uplift of the Sierra Nevada has
occurred over the last 10 million years. In the North American west
similar uplift has been, and is occurring, in other mountainous areas.
The same uplift is has been occurring in the Bolivian Andes and the New
Zealand Alps. Huggett suggests this active mountain building period
appears to be linked to the global climate change, partly through the
modification of air flow and partly by weathering. Young mountains are
more susceptible to weathering so erode more rapidly. Carbon dioxide is
removed from the atmosphere by weathering as it is combined in soluble
carbonates, which are carried to the oceans then deposited and buried.
Huggett suggests it is possible that enough carbon dioxide was removed
by the rise of the Himalayas to lead to a cooling of the global climate
that culminated in the ice age of the Quaternary (Raymo & Ruddiman,
1992; Ruddiman, 1997). This illustrates how important the geomorphic
system can be to environmental change.
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Author: M. H. Monroe
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Author: M.H.Monroe Email: admin@austhrutime.com Sources & Further reading |