How Much Do You Know About Saltation? Quiz

The correct answer is #1 suspension, #2 saltation, #3 creep. In the diagram, sand particles are shown being lifted and carried in the air, which is characteristic of suspension. This is followed by saltation, where the sand particles are seen bouncing and hopping along the ground. Finally, creep refers to the slow movement of sand particles along the ground's surface.

Saltation is the correct answer because it accurately defines saltation as the movement of sand by winds that are 10 mph or greater, resulting in the formation of dunes. This explanation aligns with the given definition and conditions under which saltation occurs.

Saltation is the process by which sand grains are lifted into the air and then fall back to the ground due to wind. It is the most common mode of sand movement by wind. The given answer of 75% suggests that saltation accounts for three-fourths of all sand movement by wind. This means that the majority of sand is transported through the air in a bouncing or hopping motion, rather than being carried along the surface or being suspended in the air.

Surface creep occurs when saltating grains of sand strike heavier grains larger than one millimeter in diameter, causing the heavier grains a slight forward movement along the surface. This explanation states that surface creep happens when larger grains are struck by saltating grains of sand, resulting in a slight forward movement of the heavier grains.

Saltation is the process by which sand grains are transported by bouncing and hopping along the surface. This process tends to carry only the finest sand grains, as larger grains are too heavy to be lifted by the wind. Therefore, dunes, which are formed by the accumulation of wind-blown sand, are made up of finer sand particles compared to beaches where larger grains can settle.

The fluid threshold refers to the wind speed required for sand particles to begin saltating, or bouncing and hopping along the ground, due to the direct force of the wind. This is the point at which the wind is strong enough to lift and transport the sand particles.

Sand tends to accumulate in piles rather than spread out evenly over an area because when there is a sufficient reduction of wind energy in the direction that sand drifts in, and any obstacle, such as a rock outcrop or a stand of vegetation, forces sand accumulation by lowering the wind speed. This means that the reduced wind energy allows the sand particles to settle and accumulate in one place rather than being carried away by the wind. The obstacles further contribute to this accumulation by creating areas of lower wind speed, causing the sand to settle and pile up.

The correct answer states that for dune formation to occur, three basic requirements are necessary. These requirements include a large supply of sand, wind speeds capable of moving the sand, and an ideal location for the sand to accumulate. This explanation highlights the essential factors needed for the formation of dunes, emphasizing the importance of sand supply, wind strength, and a suitable location for the accumulation of sand.

Sand grains average about two thousand times the weight of the atmosphere, meaning that they are significantly heavier than the air surrounding them. This explains why not all winds are able to move sand, as the force required to lift and transport such heavy particles is greater than what some winds can generate.

The correct answer is #1 sand, #2 silt, #3 clay. This is because sand particles are larger in size compared to silt and clay particles. Silt particles are smaller than sand but larger than clay particles. Clay particles are the smallest in size and have a fine texture. Therefore, the given answer accurately identifies the sediment particle sizes in increasing order of size.

Saltating sand grains are able to strike heavy grains of sand on the surface, but they do not possess enough energy to lift these heavier grains into the air. However, the impact from the saltating grains causes the heavy grains to experience a slight forward movement, known as "creep," along the surface. This suggests that the relationship between heavier grains of sand and the "creep" movement is that the saltating grains induce the creep motion in the heavy grains by striking them on the surface.