Continental Landform – A Striking Topographic Feature
We have learned the definition of a landform, which is a natural feature on the surface of the planet, Earth. The most common form of landforms is the mountains, valleys, and plateaus.
In this section, our discussion will be restricted to another landform which is - Continental landform, another outstanding topographic feature standing on the largest land areas of the Earth. Similar to these landform structures are mountains which include volcanic cones, valleys, and plateaus. All these landform structures mark quite a unique appearance by the tectonic mechanisms which are generated by them and by the climate conditions.
Continental Landform
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Among the continental landforms, the most giant tectonism in the mountainous topography, which is either generated along the continental margins which make up the earth’s layer known as the lithosphere. Further tectonic expressions are also structured by the vast continental regions of those the limited relief and the elevation which is affected by a gentle uplift, subsidence, tilting, and warping.
The denudational processes, which include the weathering of the rocks accompanied by both erosion and deposition of the rock debris are functioned by the climate. The climatic changes take place very slowly with the help of continental drift and with other factors like solar radiation.
Convergent Boundary Landforms
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A convergent boundary or the destructive boundary which is particularly an area on the Earth. Here two or more lithospheric plates collide with each other. One of the plates eventually slides beneath the other plate, this process is known as the subduction process. The subduction zone is generally defined by a plane where many earthquakes happen. The Convergent boundaries occur between the (refer to the diagram) –
oceanic-oceanic lithosphere
oceanic-continental lithosphere
continental-continental lithosphere
These geological features which are related to the convergent boundaries vary according to their crust types. There are landforms created by convergent boundaries which are caused by convergent plate boundaries, two such landforms are an ocean trench and a mountain range.
Continental Glacial Landforms
Glaciers are known as the moving bodies which change the entire landscape structures. They sculpt the mighty mountains, carve the valleys, and the glaciers also move the vast quantities of rock and sediment along with them.
In past years, glaciers are studied to have covered over one-third of Earth's surface, while they continue to flow and to remodel the shape features in many places.
The glaciers and the landscapes have their distinct shape, which provides information about the past climatic condition and thus offers an understanding of climate change today.
The Glacier Landforms
In history, glaciers have created a variety of landforms. These landforms are seen in National Parks today, like the:
1. Geologic Resource Division
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Here the glaciers carve a set of distinctive, steep-walled, flat-bottomed valleys. They are U-shaped valleys, the fjords, and hanging valleys are examples of the kinds of valleys glaciers that can erode.
2. Cirques
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Cirques are the bowl-shaped depressions that the glaciers carve into mountains and valley side walls at the higher elevations.
3. Nunataks, Aretes, and Horns
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Nunataks, arêtes, and horns are the action of glacial erosion in the areas where there were multiple glaciers that flowed in multiple directions. When the ice was present, they formed stark, rocky outcrops above this. After the ice retreats, they are uniquely shaped features that provide clearer evidence of the glacier flows.
4. Lateral and Medial Moraines
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Lateral and medial moraines consist of the transported rock and debris which were being transported. They are formed on the sides of glaciers, which is known as the lateral moraines, or at the boundary which is between the two tributary glaciers.
5. Terminal and Recessional Moraines
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The terminal and recessional moraines characterize the farthest reaches of a glacier which can be travelled at any time.
6. Glacial Till and Glacial Flour
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Here the sediments that are produced through glacial grinding are very much distinctive.
7. Glacial Erratics
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The glaciers also can pick up the chunks of rocks and transport them over long distances. These kinds of rocks are known as glacial erratics.
Oceanic Landforms
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Oceanic landforms are vast in scope and also in size. Geographically, there is only one ocean on Earth, which is being named differently in different places. This ocean is then connected by other bodies of water that surround the continents and it is being divided into five major oceanic regions which are called - the Pacific, Atlantic, Indian, Arctic, and Southern oceans.
Altogether, the oceans cover over 70 percent of the Earth's surface thus giving the planet an appearance, from space, as a blue planet.
The deep waters present in the oceans hide from the rugged mountains, vast plateaus, and also active volcanoes, which are located under the ocean. The underwater landscapes seem still under construction and destruction as the new crust is born along the mid-ocean ridges, which pushes the old crust into the depths of the fiery mantle in the ocean.
The oceans here appear to be hundreds and millions of years ago since the earth cooled from its wild and hot ball. These layers of rock which are piled together are the vast amounts of steam that the volcanoes spewed into the atmosphere and then turned to water vapour, condensed, and fell as rain. With an ocean-ocean boundary, the crust can produce a deeper trench that runs parallel to the coastline. A trench and other volcanic mountains are formed from the ocean-continent convergent zone.
FAQs on Continental Landform
1. What is a continental landform?
A continental landform is any natural feature of the Earth's solid surface found on the continents, above sea level. These features are shaped over millions of years by two main types of forces: endogenic forces (originating from within the Earth, like volcanic eruptions and plate tectonics) and exogenic forces (originating from outside, like wind, water, and ice erosion). Common examples include mountains, plateaus, and plains.
2. What are the main types of continental landforms?
The major types of continental landforms are generally classified into three categories based on their elevation and slope:
- Mountains: High, steep-sided landforms that rise significantly above the surrounding area. They are often formed by tectonic plate collisions.
- Plateaus: Large, elevated areas of flat land, also known as tablelands. They have a relatively level surface that is raised sharply above the nearby land on at least one side.
- Plains: Extensive areas of flat or gently rolling land with low elevation. They are the most common landform and are often very fertile.
3. How are major continental landforms like mountains created?
Major landforms like mountains are primarily created by powerful forces from within the Earth, known as endogenic forces. The most common process is the collision of tectonic plates. When two continental plates push against each other, the rock layers buckle, fold, and are pushed upwards to form massive fold mountains like the Himalayas. Volcanic activity also builds mountains as lava and ash accumulate over time.
4. Why are plains often considered the most suitable landforms for human settlement?
Plains are ideal for human settlement and agriculture for several key reasons. Their flat terrain makes it easy to build houses, roads, and railways. The soil in plains, especially those formed by river deposits (alluvial plains), is usually very deep and fertile, which is perfect for growing crops. Additionally, plains often have abundant access to water from rivers, supporting large populations and industries.
5. What is the main difference between continental and oceanic landforms?
The primary difference lies in their location and the type of Earth's crust they are on. Continental landforms are found on land and are part of the thick, less dense continental crust. In contrast, oceanic landforms are found on the ocean floor and are part of the thin, denser oceanic crust. Examples of continental landforms are mountains and deserts, while oceanic landforms include mid-ocean ridges and deep-sea trenches.
6. A continent is an example of which order of landform?
A continent is considered a first-order landform. Geographers classify landforms into three orders to understand their scale:
- First Order: The broadest features, which are the continents and ocean basins themselves.
- Second Order: Major features on the continents, such as mountains, plains, and plateaus.
- Third Order: Smaller, more detailed features created by erosion and deposition, like valleys, deltas, and sand dunes.
7. What is the continental shelf?
The continental shelf is the part of a continent that is submerged under shallow ocean water. It is the gently sloping, underwater edge of the continent, extending from the coastline to a point of steeper descent to the deep ocean floor, known as the shelf break. It is geologically part of the continental crust and is important for fishing and as a source of natural gas and oil.
