Author Question: What is a desert pavement? How do desert pavements probably form? What evidence supports this ... (Read 36 times)

stock · **on:** Jul 16, 2018

What is a desert pavement? How do desert pavements probably form? What evidence supports this interpretation?

What will be an ideal response?

Question 2

How do climate scientists collect temperature data from all over the world to calculate the annual global mean temperature?

What will be an ideal response?

Question 3

What does it mean to smooth graphed values? Why do climate scientists smooth temperature data?

What will be an ideal response?

Mholman93 · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

Desert pavement is a smooth surface of closely spaced pieces of gravel that covers some desert floors. Most or all pavements form when windblown particles are trapped between larger fragments at the surface. The dust settles and washes beneath the larger fragments. Over time, the accumulating dust lifts the surface clasts above a thickening layer of fine-grained sediment. This mechanism of desert pavement formation is supported by the observation of layers of silty dust beneath the pavement that do not contain gravel fragments. In addition, data revealing how long the gravel clasts have been at the surface indicates that all of them forming a particular age have been at the surface for about the same amount of time. This indicates that they were always exposed at the surface and are not a residual layer left behind as finer particles blew away.

Answer to Question 2

Land-based data comes from weather stations where measurements are made throughout each day and then averaged together for daily and annual mean values. Temperature data at sea is based on water-temperature measurements from both scientific and commercial vessels.

Answer to Question 3

Smoothing is a process of averaging together adjacent values on a graph. Smoothing makes it easier to see long-term trends within data that fluctuate over large ranges on short-term time scales.