『Abstract
A current theory that links the uplift of the Himalayas to the
drawdown of atmospheric CO2 assumes that
rates of chemical weathering are enhanced by accelerated physical
erosion due to the increased exposure of fresh minerals. Although
several studies have concluded that weathering rates do increase
with erosion rates, there is disagreement over the form of that
relationship. Some find a linear relationship between weathering
rate and erosion rate; others, however, find that weathering is
only approximately proportional to the square root of physical
erosion such that changes in erosion rate are not matched by equivalent
changes in weathering rate. Defining the nature of the relationship
is critical because it determines the sensitivity of changes in
weathering rate to changes in erosion rate. In this study, a theoretical
model that couples erosion by landslides with chemical weathering
processes was derived to explore the nature of this relationship
in rapidly eroding landscapes. Results from the model suggest
that, where landsliding is the dominant erosional process, the
rate of chemical weathering is only proportional to the erosion
rate raised to the 〜0.6 power. Therefore, even if weathering rate
is wholly dependent on erosion rate, increases in erosion will
not be matched by equivalent increases in chemical weathering.
Keywords: chemical weathering; carbon dioxide drawdown; erosion;
global climate; landslides; modeling』
1. Introduction
2. Numerical model
2.1. Development
2.2. Model parameterization
3. Results
4. Discussion and conclusion
Acknowledgments
References