Soil
• Soil comes from Parent Rock which makes up the solid part
of the Earth’s crust.
• Wind, rain and frost over time wear down the Parent Rock
into smaller fragments.
• The worn down Parent Rock then mixes with dead organic
material (detritus) to produce a layer of soil.
Soil Horizons
• As soil develops in
layers called horizons.
• The horizons are
identified by their
color, texture and
composition.
There are 3 conditions necessary for soil
to be able to support plant life:
1) Sufficient amount of minerals
2) Enough moisture
3) Appropriate soil pH
Permafrost
• Ground whose temperature has been 0 ̊C
or below for at least 2 years
• Can be found in polar regions or at high
latitudes
Permafrost
• In certain regions, the upper layer of permafrost thaws
in the summer and certain plants are able to grow. This
top layer is called the active layer. When winter returns,
the ground freezes again.
• Permafrost makes it difficult for plant roots to grow
deep into the ground. For this reason, very small/no
plants are able to survive.
• Permafrost makes agriculture impossible and construction
difficult.
Permafrost & Climate Change
• As temperatures continue to rise, permafrost
will continue to thaw.
• As permafrost melts, the once-frozen land
becomes unstable which results in landslides. The
soil is then more vulnerable to erosion.
Permafrost & Climate Change
• Permafrost stores a lot of carbon (C).
• As permafrost melts, this carbon is released into
the atmosphere in the form of methane (CH4), a
powerful greenhouse gas responsible for warming
the planet.
• This leads to more climate change and the cycle
aggravates itself.
Try This!
1. Permafrost is:
a) all the frozen water on the Earth’s surface.
b) a layer of permanently frozen soil.
c) the snow which accumulates on the surface of glaciers.
d) the upper layer of water which freezes when in
contact with cold air.
2. Chose the statement which is false.
Areas of permafrost can be challenging to live in because:
a) agriculture is not possible.
b) buildings can collapse.
c) sunshine is lacking.
d) the ground is usually frozen.
Try This!
1. Which of the following is not a possible
consequence of melting permafrost?
a) Decreased primary productivity
b) Increased erosion
c) Increased Global Warming
d) Increased decomposition of soil
2. In an area of permafrost, global warming can
increase the depth, as well as the length of time,
during which the active layer is present. How does
this affect:
a) the lithosphere?
b) plant life?
c) human life?