Constructive forces are the forces that tend to build up new landforms on the Earth’s surface. These forces also help to add new features to the landmasses that are already present on the earth. The constructive forces are accountable to cause structural changes to the earth’s surface. These forces serve to reshape the earth’s exterior. They deform the mountains, deposit new features to the land, dislocate rocks, etc. A number of mechanical structures can be developed to modulate the effect of constructive and destructive forces temporarily as per convenience; however, a total command on such forces is not possible by humans.
Examples of Constructive Forces
1. Delta Formation
Deltas are formed when a river body tends to deposit the sediments and matter contained by it into some other water body. In other words, a delta is a landmass formed as a result of the deposition of sediments. Deltas are mostly formed in the regions where a water body comes in contact with another water body. For instance, when a river enters an ocean, it forms a delta. Delta formation leads to the development of a new structure with the help of deposition, hence it is a constructive force.
2. Volcanic Eruption
Volcanoes are one of the most prominent examples of constructive forces. During a volcanic eruption, the molten lava spills out. The hot molten lava gets solidified upon cooling and becomes hard with time. This leads to the formation of a rock-like structure on the ground. The process of volcanic eruption involves driving and deposition of matter from the inner side of the earth to the exterior of the earth’s surface. This constructively adds a new characteristic to the land; therefore, it is called a constructive force.
3. Mountain Building
The earth’s crust is made up of a number of plates. These plates keep moving with time and play a major role in forming new structures on the surface of the earth. The process of movement of the earth’s plates is known as plate tectonics. Plate tectonics theory is responsible for the development of new hills and mountains on the surface of the earth. When the tectonic plates slide against each other, roughly conical structures are formed, and the surface of the earth gets reshaped. The process of mountain building does not cause wear and tear to the earth’s surface; therefore, it is listed under the category of constructive forces.
4. Glaciers Outwash
Glaciers outwash or an outwash plain is the deposition of a flat layer of sediment in front of a glacier due to the melted ice of the glacier. The melted glacier ice forms a stream that flows and carries the sediments and other materials along with it. The sediments get deposited on the ground as the stream of water formed by the melted ice loses energy. The deposition is observed in such a way that the heavy gravel particles get deposited first, whereas the lighter clay particles settle down at last. The sectional deposition of sediments is constructive in nature, and therefore the force responsible for a glacier outwash is a constructive force.
Landslides occur as a result of the weathering of the rocks and the action of gravitational force on the worn-out matter. Mostly, landslides are an example of destructive forces because they cause a lot of damage to the structure of the earth; however, in some cases, landslides also help in demonstrating constructive forces in action because they help to form folding mountains by folding and compressing a layer of rocks over another. This is the reason why landslides are listed under both constructive and destructive forces.
6. Hot Spots
Some volcanoes that are formed in the interior of the earth’s plate are known as hot spot volcanoes. When the mantle plume present in the asthenosphere rises and reaches the lithosphere, it tends to melt. The molten lava causes a disturbance, erupts, and forms an underwater volcano. The plate carrying the volcano keeps moving, which is why a chain of such volcanoes is formed. After some time, the volcanoes cool down to form islands. These islands, over the course of time, get transformed into underwater seamounts. Hence, a constructive force is said to be existing.