Glacier is formed by snow,then how does
the snow turn to glacier?
The crystalloid snowflake in original state will turn
to granular neve under earth heating power and self pressure,then
these granular neves will turn to mediumgrain,then thick
grain.The granular neves will subsided gradually under
the pressure of upper granular neves then rime to granular
ice .In
the process of granular neve turing to granular ice,the
thawy water run along with the granular neve and freeze
the granular neve in the bottom and make the air between
granules close and turn to air bubble.Granular neve contains
more air bubble and the volume is bigger which looks white,so
it is called "white ice".Because further pressure,part
of air bubbles have been removed and the remain ones have
been compressed and gradually turn to blue block ice--glacial
ice
.Block ices move under gravitation and form glacier.The
process from snowflake ,granular neve ,granular ice to
block ice is called "ice formation" in glaciology.In
this process snowflake turns to glacial ice after a series
of recrystallization metamorphism.It is the difference
between glacial ice and water ice.This process is very
slow and usually needs several decades ,even several centuries.The
older the glacier ice,the clearer the ice mass is.If you
watch close,you can easily distinguish white ice and blue
glacier ice with compressed air bubble in Hailuogou.
There is a necessary condition for the formation of
glacier that is the height of firn area should exceed
snow line .Snow line is the height where the snow thaw
every year,which is also called zero balance line of solid
precipitation.If anywhere doesn't exceed snow line,there
can be no glacier. |
| Add：Moxi Town,Ganzi Autonomous Prefecture Technical
Supporter：www.ce.net.cn
Tel(Consultation)：0836-3266203 Tel(Office)：0836-3268351 Fax：0836-3266405 |
|
|
 |
 |
