As you can see from the picture above, wind erosion is powerful enough to carve through stone. Small sediment particles picked up by the wind will strike anything in their path. In this case, this rock was eroded with sand. The wind picks up sand and carries it forward. The sand can smooth down a stone by slowly grinding at its surface. This is like using sandpaper to make wood smoother.
What are different types of wind erosion?
Wind erosion can change a landscape in two major ways. Deflation is a type of wind erosion where wind picks up and carries particles away. The second type is abrasion, which is when surfaces wear down as they are hit by particles carried by the wind. The large photo above is an example of abrasion!
There are three different categories of deflation erosion.
- Surface Creep – Surface creep is when heavy particles roll along the ground. These objects are too heavy for wind to lift, so things that move due to surface creep move slowly.
- Saltation – Saltation happens when the wind is able to lift a material enough so that it rises from the ground. Things that move by saltation are too heavy to carry away, so they drop back down again. An example of saltation is sand blowing across a desert. The wind can move sand into the air, but the sand falls back to the ground when the wind dies down.
- Suspension – Particles moved by suspension are light. When the wind carries them away, they remain suspended in the air.
Abrasion is a process that takes a long time, but is very powerful. Like the image above, abrasion can degrade even the strongest stone! How fast abrasion happens depends on a few factors. Faster wind will hit a surface harder than slower wind. This causes abrasion to happen slower. If the wind is able to carry large particles, this will wear a surface down faster than small particles. Rocks or landforms worn from abrasion will be very smooth.
What are Examples of Wind Erosion?
This is a picture from a place called Sleeping Dragon in Utah. The rocks here have been eroded by the wind via abrasion. Because they are round, the locals nickname them dragon eggs!
As wind speeds along the ground, it picks up the loose, sandy particles. Repeated hits from these particles will chip away at the rock, making it smaller. These rocks are very smooth, a strong indicator of wind abrasion.
This is a sandstorm. It’s a great example of wind erosion because it shows two types of deflation! The sand dunes are shaped by the wind. Wind will pick up sand particles and move them around. Sand particles are heavier than dust, so when the wind slows down, they fall back to Earth. This is an example of saltation. Sometimes, huge dust storms begin near sand dunes. Dust is very light, so when the wind picks it up, it stays suspended in the atmosphere. This is called suspension.
Other Great Resources
Wind Erosion – Office of Environment and Heritage, NSW, Australia: http://www.environment.nsw.gov.au/topics/land-and-soil/soil-degradation/wind-erosion
Wind Erosion – eSchoolToday: http://www.eschooltoday.com/landforms/the-process-of-wind-erosion.html
The Big Hollow and the Power of Erosion – Univ. of Wyoming: