Wind is the Reason for the Season

 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.