geology Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth ...

and

geomorphology Geomorphology () is the scientific study of the origin and evolution of topographic and bathymetric features generated by physical, chemical or biological processes operating at or near Earth's surface. Geomorphologists seek to understand wh ...

, an erosion surface is a surface of rock or regolith that was formed by

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

and not by construction (e.g.

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

flows,

sediment Sediment is a solid material that is transported to a new location where it is deposited. It occurs naturally and, through the processes of weathering and erosion, is broken down and subsequently sediment transport, transported by the action of ...

deposition) nor fault displacement. Erosional surfaces within the stratigraphic record are known as

unconformities An unconformity is a buried erosion surface, erosional or non-depositional surface separating two Rock (geology), rock masses or Stratum, strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer ...

, but not all unconformities are buried erosion surfaces. Erosion surfaces vary in scale and can be formed on a mountain range or a rock. Particularly large and flat erosion surfaces receive the names of peneplain, paleoplain, planation surface or pediplain. An example of erosion surface is road surface erosion which is caused by natural and anthropogenic factors. Erosion surface can be measured through direct, contact measurement methods and indirect, non-contact measurement methods.

Road surface erosion

Just like mountains and rocks, erosion can also occur on unsealed roads due to natural and

anthropogenic Anthropogenic ("human" + "generating") is an adjective that may refer to: * Anthropogeny, the study of the origins of humanity Anthropogenic may also refer to things that have been generated by humans, as follows: * Human impact on the enviro ...

factors. Road surface erosion could be caused by snowfall, rainfall and wind. The material and hydraulic of the road surface, road slope, traffic, construction, and maintenance could also potentially affect road surface erosion rate. During winter, snow cover slows down erosion rate by preventing direct contact between the raindrop and the road surface. For example, in the mountains of

Idaho Idaho ( ) is a landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...

, U.S., snowfall caused less than 10% while rainfall caused 90% of total annual

production on the road surface. In addition to natural factors, high traffic volume can also speed up the road erosion rates. The friction caused by moving vehicles could potentially lead to crushing and abrasion, thus break down the coarse particles on the road surface. Slope steepness is another important factor in surface erosion--steeper roads tend to have higher erosion rates. Rhizolith group revealed after wind erosion 3

Rhizolith group revealed after wind erosion 3

Measurement of erosion surface

There are two types of methods to measure the rate of surface change: direct, contact measurement methods and indirect, non-contact measurement methods. These measurement could be taken for different components of a rock or for different rock types. Rate of rock surface

recession In economics, a recession is a business cycle contraction that occurs when there is a period of broad decline in economic activity. Recessions generally occur when there is a widespread drop in spending (an adverse demand shock). This may be tr ...

can be measured by using reference points or reference planes and measure the distance among those points and plane over the years. Rock surface erosion rate can also be measured using Micro-Erosion Meter(MEM). This triangular instrument is placed on three studs that are permanently fixed into the rock surface to provide a measurement site. The extension of the probe is then used to measure erosion. Indirect, non-contact measurement methods include

laser scanning Laser scanning is the controlled Deflection (physics), deflection of laser beams, visible or invisible. Scanned laser beams are used in some 3-D printers, in rapid prototyping, in machines for material processing, in laser engraving machines, i ...

and digital

photogrammetry Photogrammetry is the science and technology of obtaining reliable information about physical objects and the environment through the process of recording, measuring and interpreting photographic images and patterns of electromagnetic radiant ima ...

. While laser scanning requires many specialist and expensive equipment, repeat photography and digital photogrammetry can also be used to obtain data for researchers with a much smaller budget.

References

Erosion landforms Geomorphology {{erosion-stub