Landforms of Plate Boundaries | Sciencing
The Relationships Between Plate Boundaries and Tectonic Landforms .. 37 We' re off to Southeastern Asia, one of the best places to observe this type of plate. Earth's crust is like a giant cracked egg. Each crust piece is called a tectonic plate and it moves. The plates interact with each other at the edges. Indonesian Landforms and Plate Tectonics The narrow North-Moluccan plate is interposed between the Asia and Pacific. It tapers out.
Tectonic landform | geology | ncsuk.info
A crack in Earth's crust forms. Magma rises through the crack, forming ridges. One example is the San Juan Ridge, a wide area of young volcanoes. Other volcanoes are created when a tectonic plate slides under another. As the bottom plate is heated up by the Earth's hot mantle, a material called magma forms.
Over time magma erupts through the plates. Many such volcanoes are found on "the Pacific Ring of Fire. Volcanoes under the ocean can lead to the formation of islands. These volcanoes are the kind produced by one plate sliding under the other. The erupting volcano adds enough material to itself to rise above the ocean's surface. Because the surface of the Earth is curved, the resulting volcanic islands are always found in arcs.
Mountains Seashell fossils are found at the top of the Himalayas.
This mystery is solved by looking at tectonic plate interaction. Huge mountain ranges are formed by similar-sized plates colliding. In this case, one plate does not slide under the other. The pressure of the two plates has to be relieved and the way this happens is by thrusting the colliding plate's edges upward. Strong, deep earthquakes and volcanic activity are found along convergent plate boundaries.
The third type of plate boundary is a transform boundary and occurs when two plates slide past each other along a fault line. Earthquakes are common along the fault lines as the plates lock up from friction until enough tension builds up to suddenly break that tension. The San Andreas Fault is an example of a transform plate boundary. This type of boundary has little volcanic activity, but earthquakes are common here and the earthquakes tend to outline the major plates. A 'Hot spot' is an isolated area of volcanic activity generally found in the middle of large tectonic plates.
A 'hot spot' is caused by the magma that rises or plumes from the mantle to the surface causing volcanoes by penetrating the crust. As the plate moves, the hot spot stays in the same place. Islands form in a "chain" as a result of plate movement.
Hot spots account for the formation of islands in the middle of the Pacific such as the Hawaiian Islands, the Line Islands, and the Tuamotus. The Hawaiian Islands are younger from northwest to southeast in the chain because the plate has moved to the northwest. On the island of Hawaii, which is still over the hot spot, volcanoes remain very active. The Galapagos Islands, off the coast of Ecuador are similar in fashion, though not as aligned.
Other events related to plate movements include earthquakes, volcanoes, and geothermal activity. Earthquakes are caused by abrupt easing of strains that have been built up along geologic faults and also by volcanic activity such as eruptions. Most of this activity exists along the fault lines between the plates.
For example, the Pacific Ocean is surrounded by a nearly continuous plate-collision zone called the ' Ring of Fire'. Both earthquakes and volcanoes are the results of instability in this zone.Plate Tectonics Explained
Japan lies near the colliding edges of three plates; hence, earthquakes and volcanoes are a particular threat there. Gradation Weathering is the physical disintegration and chemical decomposition of earth materials at or near the earth's surface.
There are different types of weathering; mechanical, physical, and chemical. Water is the driving force behind mechanical weathering. Water sculpts the earth's surface through the eroding power of rivers and waves.
One of the most striking examples of water as a weathering force is the Grand Canyon in the western U. Over the last 5 million years, the Colorado River gouged a path through rock, picking up sediment and moving it downstream.
Gradually, enough sediment was excavated to create the spectacular landscape it is today. Physical weathering breaks rocks into smaller pieces.
- The Relationships Between Plate Boundaries and Tectonic Landforms
- Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds
Animals, insects, worms, and burrowing mammals all work to loosen the soil by aeration and by mixing loose materials.
In warm weather, water soaks into cracks of rocks. Then the water freezes when the temperature cools enough. The expansion of frozen water in the cracks pushes hard enough to split the rock. This is why concrete roads are covered in potholes every spring.
Chemical weathering is very complex, but basically, it is the reaction of earth materials with atmospheric components such as water, oxygen, and carbon dioxide. Rain, streams, and seawater dissolve some substances from rock and may cause the remaining substances from the rock to crumble.
The main cause of chemical weathering is the dissolving action of water. There are other factors that may cause weathering such as humidity, pollution, acid rain, and wind. There are monuments in Luxor, Egypt with writing that has remained visible for over years, but when the same ruins are sent to New York as a gift from the government of Egypt, the writing is quickly is worn away and is no longer legible. All in all, the rate of chemical weathering is controlled by the surface environment, grain size, and the climate.
Rivers, especially fast-moving rivers, erode the land by carrying sediment away from one location and depositing it in another. The Missouri River Valley has been formed by this slow-moving erosional force. Tributaries are bodies of water which flow into a larger river. These form valleys within a larger valley, leaving hills on each side. Rivers, at a certain stage of development, move back and forth in a snake-like pattern causing erosion and deposition. This may cause the river to become so tightly curved that the river takes a short-cut and create a loop or an oxbow lake.
Lake Manawa and Carter Lake are two examples of oxbow lakes in the Midwest. Waves are formed when wind blows over calm waters and ripples are created. These ripples enlarge with time and form larger waves. These waves then crash into continents and are a very powerful gradational force.
They wear away the sides of continents. There have been islands that were formed by volcanic action and were worn away by waves in a few short years. Beaches are continually being changed by the waves and can be created and destroyed very quickly. The Earth periodically undergoes periods of glaciation. This is a time during in which global temperatures drop causing significant environmental changes.
Glaciers are large masses of ice that act as a significant erosional force. During the Ice Age, ten thousand years ago, glaciers covered large areas of land, wore away the surface, and disrupted the drainage system. Alpine glaciers create large U-shaped glacial valleys and cut through large mountains.
Large boulders have been moved and deposited hundreds of miles from where they were absorbed into the glacier. A glacial landscape, as seen in northern Wisconsin, Minnesota, and large parts of Canada, is one in which the natural drainage system has been disrupted. This causes many lakes to form where glaciers once existed.
Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds
If global warming continues, the glaciers will begin to melt and causing a rise in the levels of the oceans. If the global temperature increases just three degrees by the yearthe sea levels will rise 8 inches from the alpine glaciers alone. Another gradational force is known as Mass Wasting. This is the movement of loosened rock or soil down a slope due to gravity.
Mass wasting can occur as quickly as a few seconds or can as a process of hundreds of years. The steeper the elevation, the quicker mass wasting occurs. Mass Wasting can take the form of rock falls, mudflows, and landslides. Deposition Deposition is the process of eroding sediment deposited elsewhere. Erosion is a natural process that moves fragmented rock and soil over long distances using the wind or water.
When rivers flood over their banks, large amounts of silt are deposited onto the flooded land. Due to the repeated flooding of some rivers, the land surrounding the river flattens out, creating a flood plain. This floodplain has a rich soil, excellent for agriculture, because of the flooding and deposition of nutrients. When the river reaches a large body of water, such as a lake or ocean, the water slows and is not able to support its load of sediments.
A delta is where the river spreads out over a large area, depositing the sediments, often spread out in a triangular shape. As more sediments are deposited, the shoreline grows outward in an arc.
Sandbars are offshore shoals of sand deposited by slower moving water. Sandbars often form in the curves of rivers as the water slows to go around the curve.
Sandbars also form in areas where the river spreads out over a larger area, which also slows the water flow. A moraine is the sediment left behind by the melting of a glacier.
As glaciers move, large amounts of the ground underneath is picked up and carried along with it. In a time of equilibrium, when the glacier is neither growing nor receding, a terminal moraine is formed along the leading edge.