The main dunefield of Great Sand Dunes is primarily made up of reversing dunes and star dunes. NPS/Fred Bunch
Great Sand Dunes National Park contains unlike types of dunes, each explained below through images and animations. Each dune type is the result of different wind patterns, and the presence or lack of vegetation on the grind .
Reversing Dunes : The Most Common Dune in the Dunefield ( aim proxy )
NPS/Great Sand Dunes NPP
“Chinese Walls” form on tops of reversing dunes (see animation above).
“ chinese Walls ” shape on tops of reversing dunes ( see liveliness above ) .
Star dunes have three or more arms, formed from multiple wind directions. NPS/Great Sand Dunes NPP
Star Dunes
Where star dunes are salute, an sphere ‘s wind government is building complex. Star dunes form alone in places where wind blows from vary directions over the class of a year. At Great Sand Dunes, a large star topology dune complex occur in the northeasterly corner of the dunefield. The tallest dune at Great Sand Dunes is 750 ‘ ( 229m ), and known merely as The Star Dune .
Animation showing the formation of a parabolic dune. NPS/David Zelenka
Parabolic Dunes
much of the backbone sheet is covered with vegetation. If potent winds erode a incision of the vegetate sand ( normally referred to as a blowout ), a parabolic dune may form. Leeward apparent motion occurs if sand from the blowout is deposited on the opposite slope of the parabolic dune. Vegetation holds the “ arms ” of the dune in target as the leeward “ nose ” of the dune migrates forward toward the main dunefield. parabolic dunes are common in the sand sheet southwesterly of the independent dunefield.
Purple lines mark parabolic dunes that are migrating with southwesterly winds toward the main dunefield. NPS/Great Sand Dunes NPP
On the backbone sheet, parabolic dunes are still migrating today toward the main dunefield. vegetation on the valley floor causes them to become parabolic dunes quite than barchan dunes ( below ) .
Barchan (“BAR-kahn”) dunes form in areas with only one wind direction, and little or no vegetation. NPS/Patrick Myers
Barchan Dunes
If conditions were “ perfect ” —the landscape was flat, winds blew from only one focus, vegetation could not grow, and backbone was available but circumscribed —barchan dunes would dominate a sandscape. Since those conditions are rarely found at Great Sand Dunes, a very complex dune system emerges. tied so, classic barchan dunes can be found at respective locations throughout the park. Look for classical barchan dunes directly across from the independent Dunes Parking Area. As the sand supply increases, barchan dunes begin to connect with others forming barchanoid ridges. If the ridges become fairly straight, scientists call them cross dunes ( below ) .
Barchan dunes along Medano Creek can eventually align and join into long ridges called transverse dunes. NPS/Patrick Myers
Transverse Dunes
Barchan dunes ( above ) can become align together along a plane perpendicular to the fart. If the line becomes reasonably square, dune scientists refer to these fore march ridges as cross dunes. They progress forward as their leeward slipfaces release sand one avalanche at a time. Along the southerly boundary of the dunefield, a series of cross dunes are fed by recycle backbone transported by Medano Creek .
NPS/Andrew Valdez
Nebkha or Coppice Dunes
Nebkha dunes ( besides known as brush dunes ) are childlike dunes that form around vegetation, chiefly on the sandpaper sheet. Clumps of shrub and grass begin to gather windblown sand ; as the backbone gets deeper, the plants besides grow tall, allowing more backbone to gather around them .