Transcript rates of weathering

Rates of Weathering
Topic 9
Regents Earth Science
The rate of weathering is
affected by
1. Climate
 Humidity
- frost action generally
increases with humidity (if temperatures
are right) ~ need temperatures above
and below freezing
 Temperature - chemical weathering
increases with increasing humidity and
higher temperatures
1. Climate continued . . .
 Local
prevailing winds - weathering
greatest on windward side
 Other local conditions such as
• carbon dioxide concentration (more
CO2, more weathering)
• urban heat islands (higher
temperature, more weathering)
Dominant weathering for
various climate conditions
Weathering and direction
Remember
 Hot
humid = highest rate of weathering
 Cold and dry = slowest weathering
2. Particle size
 The
smaller the particle, the greater the
surface area
 Small particles weather faster than large
particles under the same conditions
3. Mineral composition
 Rock
of different composition weather at
different rates
4. Exposure
 The
degree to which a rock comes into
contact with weathering agents
 Protected rocks weather more slowly
than those completely exposed at the
surface
 Also affects each particle causing it to
become more rounded