Antarctica has two seasons. The earth has different
seasons because of its tilt. The tilt of the earth dictates the amount of sun
light the northern or southern hemisphere receives. The earth's tilt maintains
the same angle, so when the southern hemisphere is facing the sun in its orbit
the southern hemisphere is receiving more sunlight. On the opposite side of the
sun the tilt still maintains its angle, so now the northern hemisphere is more
direct towards the sun and the southern hemisphere receives less sunlight;
making it winter in Antarctica.
The concept of volcanic activity in Antarctica is a
hard one to grasp at first, considering that it is about 98% covered by the
Antarctic Ice Sheet. However, there are volcanoes such as, Mount Berlin, Mount
Hampton, and Mount Kauffman. Mount Hampton
actually is a volcanic caldera, which is unique in the way it is formed. A
volcanic caldera is usually formed when a collapse of land occurs followed by a
volcanic eruption. It is commonly described as having the shape of an inverse
volcano.
Mount Berlin is a combination of two shield volcanoes. A shield volcano
is considered the least dangerous because of its low viscosity. The flow would
be slow enough to give a person a chance to out run the magma flow. Volcanoes
at Mount Berlin have not been active for a long time. This is known because the
youngest tephra layer was aged to be 10.3 thousand years at the base of an ice
cave. Tephra is rock particles that are ejected out of a volcano because of an
eruption. This is why Mount Berlin volcanoes are considered to no longer be
active because the youngest evidence of eruption was about 10.3 thousand years
ago.
This is a picture of Mount Hampton, an example of a volcanic caldera in Antarctica.
Mount Berlin
Reference:
http://www.volcano.si.edu/world/volcano.cfm?vnum=1900-022
