Natural Environment: Importance and Definition
In this article, we will read about the land of the earth like- rocks, minerals, fossils, volcanoes, plains, plateaus,s, etc. Earth’s natural environment is divided into four regions:
Lithosphere, atmosphere, hydrosphere, and biosphere
1. Sthal Mandal is related to land.
2. Atmosphere is related to air.
3. Hydrosphere is related to water.
4. Biosphere is related to life forms like plants and animals etc.
Ecological balance is dependent on ideal conditions of natural existence where each area helps the other. Any disturbance in the ecological balance can put everyone’s life in danger. Nothing is motionless in this world. It changes with time.
Earth formed about 4500 million years ago. It has been going through many changes since its inception
29 percent of the Earth’s surface is covered by water. The Pacific Ocean itself covers an area of 60 million km. It is bigger than all the subcontinents and islands combined. The distribution of water and land can be affected by the distribution of climate and by tectonic activity.
The unequal distribution of land and water has a major impact on the climate structure of the world. Oceans are the main source of moisture for precipitation. They also store our heat.
The boundaries of oceans and peninsulas set by coastlines suggest an easy natural way to divide the world. This is the face of the Earth as seen from space. It provides a meaningful basis for organizing our environment.
The Inequality of Land
There are many different types of landforms on the surface of our earth. Here there are high mountains and deep valleys, pine plains, and plateaus. Plateau is a high region but its peak is flat and the slope is less steep.
The highest peak on Earth is Mount Everest in the Himalayas, which is 8848 meters above sea level. The lowest point is the Mariana Trench of the Pacific Ocean which is 11340 meters deep from the sea level.
This diversity of landforms has influenced the spread and activities of people on the Earth’s surface.
Interior of the Earth
Most of our knowledge of the Earth’s interior comes from indirect sources. The main sources of this are seismic waves generated by earthquakes.
The bumps and vibrations of the earth’s crust are called earthquakes. They move in different directions and at different speeds from the epicenter of the earthquake toward the earth’s surface.
Their speed depends on the nature of the substance passing through them. Earthquake waves are mainly of two types, primary and secondary.” By studying these waves, we are able to know about the internal structure of the earth. The earth is made up of three layers.
It is a thin, solid layer that is its topmost layer. Its thickness varies from one place to another. The part which forms the ocean floor is 4 to 7 km thick. Its average is 35 km in the peninsulas. The crust is up to 70 km thick under some mountains. Soil is the topmost layer of the crust.
The very thick layer beneath the crust is called the mantle. It is up to 2900 km in depth.
The entire casing is not uniform. Its upper part is about 100 km. The part below 100 is the lower fascia.
The inner part is called the center. Its radius is 3470 km, which is divided into two parts inner iron and nickel are the main components of this layer, due to which it is called Knife.
When people dig into the crust for minerals or oil, they find the rocks much hotter than the inner surface.
Sometimes hot material from inside the Earth comes out through cracks, such as lava from a volcano. When molten material rises from the ocean floor, it creates a new ocean floor.
This molten material is called magma. Deposits of lava on the land surface can also form mountains. Mount Fujiyama of Japan is an example of this.
The spreading of the ocean floor breaks the crust into many large pieces. These are called dynamic plates. The Earth’s crust is made up of seven very large and many small plates.
According to geologists, the Himalayas and the Andes were formed due to the collision of the mountain plates. This collision pushed one plate onto another, and the material between the plates came up and became mountains.
Rocks and Minerals
Earth is made up of rocks and minerals. The solid rocks that make up the Earth’s crust. Any hard part of the earth’s crust can be called a rock.
A rock can be said to be a group of minerals. Rocks are most of the solid material of the lithosphere.
Rocks can be hard or soft. Most rocks are a mixture of different minerals in different proportions. A mineral is a natural substance that has a definite chemical composition and physical properties.
A rock that consists of a single mineral in large proportion and can be extracted at a low cost, that mineral is called an ore. Magnetite is an ore of iron.
Types of Rocks
The earth’s crust is made up of different types of rocks which differ from each other in composition, composition, color, etc. On the basis of their formation, rocks can be divided into three parts:
1. Igneous Rocks
2. Sedimentary Rocks
3. Metamorphic Rocks
All these can be divided into many parts on the basis of their chemical and physical properties.
Igneous rocks are the solidified form of molten material released from inside the earth. The rocks inside the earth are in a molten state.
This molten material is called magma (liquid rock). It comes to the surface in molten or solid form due to volcanic activity.
Igneous rocks are the deposition and solidification of volcanic material. Igneous rocks are igneous in nature and are called primary rocks because they are the first rocks found.
They are generally hard with no crust and no fossils. Apart from this, due to being crystal, even water cannot pass through them.
Uses: Since these rocks are hard and do not erode easily, they make good building materials. Granite, basalt, gabbro, dolerite, feldspar, pumice, obsidian, and scoria are some examples of these rocks. The ores of most metallic minerals are associated with igneous rocks.
Kinds of Volcanoes
The volcanoes which spew lava from time to time are called active volcanoes. There are about 500 active volcanoes in the world in total.
These volcanoes erupted in the past but are now inactive for a long time. These are called dormant volcanoes.
They will erupt again in the future The volcano, located on an uninhabited island of India’s Andaman and Nicobar Islands, was dormant before becoming active recently.
There are some dormant volcanoes in the West Indies, the Philippines, and Japan.
These are volcanoes that were active a long time ago. But now they have been dormant for so long that there is no possibility of their eruption in the future. Mount Kilimanjaro in East Africa is an example of such a volcano.
World Distribution of Volcanoes
There is a crack in the earth’s crust through which the molten rock or lava and gases inside the earth come rapidly towards the surface of the earth which is called a volcano. Most active volcanoes are found in two main regions of crust stability.
The Circum Pacific Belt
About 80 percent of all active volcanoes are in this belt that encircles the Pacific Ocean. Due to the presence of a large number of volcanoes here, it is also called the ‘Pacific Ring of Fire’.
The main active volcanoes are the Andes Mountains of South America,
the Rocky Mountains of North America, the Aleutian Islands and the Kuril and Japanese Islands, Taiwan, the Philippines and the Indonesian Islands, New Zealand, and the Hawaiian Islands, as well as a large number of volcanoes.
The Mediterranean Belt
It is also called the ‘Middle World Mountain Belt’, it extends from the Mediterranean Sea to the Himalayas. It includes the Alpine and Himalayan mountain systems.
From the eastern region of the Himalayas, it turns south and extends up to Andaman, Nikabar.
It meets Indonesia in the Pacific belt. The young fold mountains of this belt are the Alpine and the Himalayas.
Major Land Forms
Mountains, plateaus, and plains are the main landforms.
Mountains are amazing figures raised about 100 meters from the surface of the land, when they are above 1600 meters, they are called mountains and when they are below, they are called hills.
It becomes very high from its surrounding area. Mountains have steep slopes, peaks, and steep ranges.
Types of Mountains
Young and Old Mountains
The characteristics of young mountains are sharp. The symptoms of old people are circular. The Himalayas are comparatively young mountains. Aravalli is an old mountain.
These mountains are formed due to forces exerting pressure from opposite directions. twist or parallel there are chains. They are caused by the twisting and lifting of the earth’s crust.
The Nilgiri mountain range of Tamil Nadu has been formed by rivers, winds, and other external factors of the surrounding land. The Rajmahal hills of Bihar-Bengal are also examples of residual mountains. Mountains are also formed by the erosion of volcanic materials.
The surface of the Itars is raised from the surrounding flat land. These are formed by the lifting of the crust at some point in time.
The plateaus of Western Australia and Southern Africa acquired their original landform during the formation of the Earth’s crust.
Some plateaus are divided by rivers. Others, such as Tibet, are surrounded by mountains. The South Peninsular Plateau of India is the oldest plateau in the world.
A plain is a wide area of land that is either flat or somewhat undulating. Plains are also called lowlands.
These are made of sediments that have been brought down by rivers.
(i) The Gangetic Plain of India is an example of such plains.
(ii) Drift Plains: These are formed by glacial deposits; Like Canada.
(iii) Depositional Plains: The flowing winds form the depository plains; such as Northwest China. These plains are formed due to the sand carried by the wind.
(iv) Refuge Plain (Plain Formed in Erosion): These are formed by the erosion of plateaus and mountains. The Canadian Shield is an example of such plains.
(v) Structural Plains: Structural plains are formed where a sea floor surrounds a raised peninsula. The South Eastern Plains in America is formed in this way.
Formation of Soil
If weathered rock particles remain exposed for a long time, chemical and organic changes take place. These changes turn small pieces of rock into soil.
Soils are very important for the growth of plants. The formation of soils depends on the climate of the place, rock types, vegetation, and slope of the land.