Earth's Changing Surface Quiz

Soil depletion refers to the loss of nutrients in the soil to such an extent that it becomes unable to support plant life. This can happen due to various factors such as overuse of fertilizers, erosion, and inadequate crop rotation. When the soil loses essential nutrients like nitrogen, phosphorus, and potassium, it becomes less fertile and unable to sustain healthy plant growth. Soil depletion is a serious issue that can lead to decreased agricultural productivity and the need for additional fertilizers to compensate for the nutrient loss.

The brown or red color of some rocks is due to a chemical reaction with oxygen, known as oxidation. When rocks are exposed to oxygen, certain minerals within them undergo a reaction that causes them to change color. This process is commonly seen in iron-rich rocks, where the iron minerals react with oxygen to form iron oxide, giving the rocks a brown or red color.

Mudflow refers to the movement of water mixed with mud. It occurs when water-saturated soil or sediment becomes unstable and flows downhill, carrying along with it a significant amount of mud, rocks, and debris. This phenomenon is commonly triggered by heavy rainfall, melting snow, or volcanic activity. Mudflows can be extremely destructive, causing erosion, property damage, and even loss of life. Therefore, the correct answer is "the movement of water with mud."

Frost wedging is a process that occurs when water seeps into cracks in rocks or other materials, freezes, and expands. This expansion exerts pressure on the surrounding material, causing it to crack or break apart. In the case of the play dough around the balloon, the water within the play dough froze and expanded, leading to the cracking or breaking of the play dough. This process is known as frost wedging and is responsible for the cracking of the play dough.

The answer is correct because the color of the subsoil is influenced by the parent material. In this case, the redish color indicates the presence of iron oxide minerals, which are commonly found in soils derived from weathered rocks rich in iron. The red color can also be an indication of good drainage and aeration in the subsoil.

The given answer "All of the above" is correct because all the statements mentioned in the question are true for topsoil. Topsoil is typically dark brown or black in color due to the presence of organic matter. It is composed of fine particles, which gives it a loose and crumbly texture. Additionally, topsoil contains minerals that are essential for plant growth, as well as humus, which is decomposed organic matter that enriches the soil. Therefore, all of the statements mentioned - dark brown/black color, fine particles, and minerals mixed with humus - accurately describe topsoil.

A volcanic neck refers to the top of a volcano that is filled with igneous rock. This occurs when magma solidifies inside the volcanic vent after an eruption. Over time, the surrounding volcanic material erodes away, leaving behind a solidified plug of magma. This hardened magma forms a distinct feature known as a volcanic neck. It is a remnant of the volcano's once-active state and provides valuable insights into the geological history of the area.

The transported soil comes from the weathering of rocks that moves with water. This process involves the breaking down of rocks into smaller particles through various physical and chemical processes. These particles are then transported by water, such as rivers and streams, and deposited in different locations. This weathering and transportation of rocks contribute to the formation of new soil in different areas.