Did you see the sink in your bathroom or kitchen? What are they called? A basin. Yes, they are basins, but the basins we will discuss here differ from those in your home.
When it comes to the definition of a basin in geography, the shape tells everything, like
a place or area where the piece of surface is lower than the Earth’s surface, and the sides are higher and in slope, like in the pacific basin OR an area with a lower center and higher edges, like an Amazon basin from which the water easily runs down into a river.
More precisely, it is a dip or a depression in a bowl-shaped with higher edges than the bottom of the Earth’s surface. Mostly circular or oval in shape like a sink or a tub, some contain water, while others are barren or empty.
Instead of any other science, it’s the forces that cause the formation of basins. The pressure may be exerted from outside, like in erosion (above the ground), or inside, like in earthquakes (below the ground).
According to Rocky Mountain Geological Consulting studies, there is no fixed time for the formation of basins; some need thousands of years, while others are created overnight.
Let’s discuss the major types of basins in detail.
River Drainage Basins
A river basin comprises all areas starting from where the precipitation falls onto the ground and ending at the river or oceans; it includes all the groundwater, headwaters, tributaries, streams, lakes, ponds, rivers, floodplains, delta, watersheds, etc.
A river basin has a collection of many watersheds; that’s why many call a watershed a smaller version of a river basin. Thus, waterfalls in the form of rain or snow on the headwaters, the peaks of mountains and then flows in the form of tributaries and streams, draining into wetlands and larger stream and forming lakes and ponds or further flows in a river form and drains into the ocean.
For example, the Mississippi River basin in the United States has comprised six major watersheds:
- Missouri
- Upper Mississippi
- Ohio
- Tennessee
- Lower Mississippi
- Arkansas-Red-White Rivers
With its vast network of waterways, the Amazon Basin, situated in northern South America, stands as the world’s largest river basin. The basin comprises the Amazon River and all its tributaries, covering an expanse of over 7 million square kilometers (equivalent to roughly 3 million square miles).
Structural Basins
The Earth’s crust has large pieces known as tectonic plates. The activity of the movement of these tectonic plates is the real reason behind the formation of structural basins.
In simple terms, tectonic movement causes earthquakes and volcanic eruptions, which cause major changes on the Earth’s surface.
The dissolving process of Rocks and Minerals on the Earth’s surface, known as weathering and erosion, both contribute to the formation of structural basins.
If you see a structural basin, you will figure out that the rocks and materials which were present on the floor were pushed downward through external and internal forces, and the sides were pushed upward. Such a basin needs thousands of years for formation. They are primarily found in dry regions.
Structural basins which have internal drainage systems are endorheic basins. These basins cannot drain water to streams, lakes, or oceans because of insufficient water supply; instead, if water enters these basins, it either evaporates or is absorbed by the soil.
If enough water accumulates in an endorheic basin, it can give rise to a highly saline lake, such as the Dead Sea, which straddles the border of Israel and Jordan. As water evaporates, the remaining minerals become more concentrated, resulting in an even saltier body of water. The Dead Sea is the most saline natural lake in the world, and its shoreline, which lies approximately 400 meters (1,300 feet) below sea level, is the planet’s lowest point of dry land.
Another example is Death Valley, located in the U.S. state of California, which sits about 86 meters (282 feet) below sea level, making it North America’s lowest point. Water from the few streams that flow into Death Valley does not flow out of the basin into a river or estuary, but rather it evaporates or seeps into the ground.
A lake basin is formed when rocks or debris block a valley, trapping water and creating a lake. This can occur due to landslides, lava flows, or glaciers. For example, the Hunza Lake in Pakistan was formed from a landslide in 2010. However, concerns remain about the basin’s strength to hold the water.
Glaciers can also create lake basins as they move down valleys. Glaciers created the Finger Lakes in New York during the last ice age.
Sedimentary basins differ from typical basins as they form long troughs filled with rock and organic material layers over millions of years. These basins are vital sources of petroleum and other fossil fuels. For instance, the remains of tiny sea creatures called diatoms, found in dried-up ocean basins, can turn into petroleum under the right conditions.
The Niger Delta sedimentary basin in Nigeria, Cameroon, and Equatorial Guinea is Africa’s highly productive petroleum field. The western Canadian Sedimentary Basin in North America is a significant supplier of gas and coal. Companies like Permian Basin Geological Consultant provides the service of monitoring, studying, and evaluating the resources of natural gas, coal, and oil resources and helping many small businesses.
Ocean Basins
Ocean basins are enormous depressions on Earth, and the edges of the continents form the sides of these basins. There are five major ocean basins coordinating with the world’s oceans: the Pacific, Atlantic, Indian, Arctic, and Southern basins. Seafloor spreading and subduction are the most significant types of tectonic activity that shape ocean basins.
Seafloor spreading happens at the boundaries of tectonic plates that are moving apart, creating new seafloor at the bottom of a mid-ocean ridge. The Atlantic basin is expanding due to seafloor spreading. Conversely, subduction occurs when tectonic plates collide, with the heavier plate subducting under the lighter one. Ocean basins that experience subduction, such as the Pacific basin, are shrinking.
Despite covering over 70% of the Earth’s surface, scientists know relatively little about ocean basins. Landforms such as trenches and mid-ocean ridges are thousands of feet below the surface of the water, making them challenging to study. However, researchers occasionally explore ocean basins in special submarines called submersibles.
