|Early morning at Stovepipe Wells|
As you can see from the photo above, it's a sandy part of Death Valley. In fact, just a short drive from the campground (~ 2 miles) are the Mesquite Flat Sand Dunes, so called because of the mesquite trees among the dunes.
|The dunes cover a large area, although the highest one is only 100 feet|
Sand dunes are formed by wind-blown sand. When the sand supply, wind direction, and velocity change, so does the type of sand dune that forms:
- Transverse: constant wind direction and large sand supply
- Barchan (crescent): constant wind direction but limited sand supply
- Linear (seif): converging winds and limited sand supply
- Star: variable wind direction
|The wind blows the sand up the long windward slope and down the steep leeward slope.|
|This photo is of the steep (leeward) side of the dunes.|
I think the stripe of shadow going down the dune on the right side of the picture is where we went dune running.
|Assuming that the shadows are on the leeward side, the prevailing winds blow in the direction of the arrows.|
These are mainly linear dunes, but the smallest arrow is pointing to a set of barchan dunes.
|Snake track. Photo courtesy of Callum McMillan.|
|The sand dunes are surrounded by mountains.|
In my last post I showed some pictures of sand dunes preserved in the rocks in Australia. Here's one of those photos again, this time annotated to show the wind direction when the dunes formed.
|At least two different sets of dunes preserved in the Mereenie Sandstone in Australia.|
The arrows show the paleowind direction.
If you want to know more about how sand dunes form, I encourage you to look at Chapter 16 of Earths Dynamic Systems, found online here.