Wind put
simply is air in motion. Most people (including myself) dislike this
geographical phenomenon, but in reality wind is extremely important to Earth's
form and the way it works. Specifically, for the interest of the blog, wind is
an extremely important to the formation and existence of the Great Sand Dunes
National Park. As I discussed in an earlier blog, the Sand Dunes were formed in
the San Luis Valley floor. Lake bed deposits were found by geologists within
the valley floor in 2002. There were smaller lakes the covered the valley floor
also, but with climate change these lakes disappeared, leaving behind a “sand
sheet”. This is where the wind comes into play in forming the dunes. Predominant
winds blow the sand towards the mountain range while wind during storms, or
storm winds, blow the sand back towards the valley. The opposite blowing of
these winds is what causes the dunes to grow as it piles the sand upwards. Wind
is also the reason that different dune types occur within the park. Different wind
types are what cause each of the different dune types. These types are reversing
dunes, Chinese wall dunes, star dunes, parabolic dunes, barchan dunes,
transverse dunes, and coppice dunes. I discussed earlier how reversing dunes
are formed by predominant and storm winds. Chinese walls are what form on top
of the reversing dunes. Parabolic Dunes are formed due to the type of
vegetation growing in the sand. Barchan dunes are formed from winds that only blow
in one direction. Coppice dunes are the dunes formed around large vegetation.
Star dunes are formed by winds that blow from different directions over the
course of a year. An excellent animation
that explains how different wind patterns form each of these different dunes
types can be found here: http://www.nps.gov/grsa/naturescience/dune-types.htm.
Although not always the most favorite climate phenomenon, wind is extremely
important to the existence of the Great Sand Dunes National Park.
