Realms of the Earth
Delve into the Realms of the Earth with our comprehensive study. Explore the intricate layers of the geosphere, hydrosphere, atmosphere, and biosphere. Gain insights into their interactions, significance, and impact on life on our planet. Perfect for students, researchers, and enthusiasts of Earth sciences.
Realms of the Earth: Detailed Study
Realms of the Earth
The three realms of the earth are the lithosphere (geosphere), atmosphere, and hydrosphere. The fourth realm of the Earth is the parts of the Earth's lithosphere (land )hydrosphere (water) and atmosphere (air) occupied by living organisms which is called the biosphere.
Lithosphere or Geosphere:
It is the solid rocky crust covering the entire planet. The crust is inorganic and is composed of rocks, minerals and elements, which covers the entire surface of the Earth from the top of Mount Everest to the bottom of the Mariana Trench. It is the topmost crust of the earth and has a thickness in the continental regions but becomes thin under the ocean beds between 6 to 12 km, It is about 60 km thick in the high mountain regions. The land area constitutes about 29 percent of the total surface area of the Earth. On the surface of the Earth, the lithosphere is composed of three main types of rocks- igneous, sedimentary and metamorphic.
(a) Igneous Rocks: These are solidified directly from molten materials. These rocks are also called primary rocks as other rocks originate from igneous rocks. There are two types- Extrusive rocks, viz- Lava and pumice, another is intrusive rocks- as some granites or gabbro which is high in calcium and magnesium and low in silicon. The intrusive rocks are solidified under the surface, while the extrusive rocks are solidified on the surface.
(b) Sedimentary Rocks: Sedimentary Rocks are formed from materials that have accumulated as a result of various processes, viz by the build-up of particles derived from other rocks or from the remains of organically formed matter or from deposits created by chemical action. Bituminous, lignite, coal and peat is the result of the decomposition of the organic matter, whereas limestone, chalk and gypsum are formed by chemical sedimentation.
(c) Metamorphic Rocks: The igneous or sedimentary are changed by pressure, heat or action of water formed metamorphic rocks. viz. granite (igneous rock) turn into a gneiss, limestone (sedimentary rock) turn into marble, sandstone into quartzite etc.
Hydrosphere:
It is the combined mass of water found under and over the surface of the Earth. About 71 percent of Earth's surface is covered by water in the form of oceans, seas, bays, gulfs, rivers, lakes etc. The oceans contain most of the Earth’s surface water and most freshwater is frozen into glaciers. Mostly the freshwater is stored underground as groundwater. The largest ocean, the Pacific Ocean, sprawls over an area of about 165,7250,000 sq. km. an area that is more than the total combined area of all the continents.
The average depth of the ocean is 3.5 km. The deepest is Challenger Deep a part of the Mariana Trench (Pacific Ocean) with a depth is 11.002 km. The total water of oceans is 1.3X 109 cubic km, which is more than 97% of the world’s total water. The ocean floor consists of three main zones, viz, the continental shelf, continental slope, and the abyss. The continental shelf (Littoral) is the sea bed bordering the continents, which is covered by shallow water up to about 600 feet. The Continental slope is the next region of the continental shelf and has a depth of 12000 feet. The abyssal zone is 9,800 to 19,700 feet (3,000 to 6,000 meters) deep and it covers 60% of the ocean and it remains in perpetual darkness. 57% of the Hydrosphere is located in the Southern hemisphere.
Pacific Ocean: It is the largest and deepest on Earth. It extends from the Ocean in the north to the Southern Ocean in the south and is bounded by the continents of Asia and Australia in the west and the Americas in the east. It covers one-third of the earth's surface. At least 20,000 small and large islands are there, Indonesia, the Philippines, New Zealand, Taiwan, Japan etc. are among them. Important seas of the Pacific Ocean are the Bering Sea, Ukotsk, Japan, South China Sea, Philippines, Alaska Sea etc.
Atlantic Ocean: It is the second-largest ocean after The Pacific Ocean, one-sixth of the total earth’s surface area. It looks like the English letter ‘S’. In North Greenland and the Northern Ocean, in the South Sothern Ocean, in Eastern Europe and Africa continent, and in Western North America and South America. Many small and large islands are found in this ocean; among them Iceland, British islands, West Indian islands, Canary Islands, Falkland, Bermuda, etc, are important. Mediterranean Sea, Baltic Sea, Caribbean, Mexico, Labrador Sea, Hudson Sea etc. are the noted seas of this ocean.
Indian Ocean: It is the third-largest ocean after the Atlantic Ocean. In the north Indian sub-continent and Southeast Asia, in the South-Southern Ocean, in the east-Australia and islands of south-eastern Asia, and in West Africa and Madagascar. Few trenches namely- Socotra-Chaos, Sichili, Madagascar, Sunda Trench, etc. The famous seas of this ocean are- the Arabian Sea, the Persian Gulf, the Bay of Bengal, the Andaman Sea, the Red Sea, etc. A few noted islands are- Srilanka, Andaman Nicobar Islands, Indonesia, Maldives, Mauritius, Madagascar etc.
Southern Ocean: It is the fourth largest ocean encircling the Antarctica continent. It is also called the Antarctica Ocean. It is mainly the extending part of the Pacific, Atlantic, and Indian oceans. It is covered by ice around the year.
Arctic Ocean: The smallest ocean and surrounds the North Pole, so it is a circular shape. The northern part of Asia, Europe, and North America surround this ocean. It is covered by ice maximum time of the year. Parts of Russia, Greenland, Alaska, Canada, Finland, Iceland, Norway, and Sweden are located here.
Atmosphere:
It is made up of gases such as nitrogen (78 percent), oxygen (21 percent), and small amounts of carbon dioxide argon, ammonia, and a few others. Water vapor is also present in the atmosphere. The atmosphere has several different layers. Higher up the air gets thinner and colder and there is less oxygen to breathe. 99% of atmospheric components are found within 32 km of the earth's surface. The atmospheric level is mainly divided into two parts- the Homosphere and the Heterosphere. Homosphere consists of the Troposphere, Stratosphere, and Mesosphere, whereas Heterosphere consists of the Thermosphere and Exosphere. Depending on molecular mass from 80 km of earth's surface to 200 km Nitrogen layer is found, from 400 km to 1125 km Oxyegn layer is extended, then the Helium layer (up to 3540 km), and at the end Hydrogen layer (up to 10,000 km) are found.
Structure of the Atmosphere:
The atmospheric layers are not of uniform thickness or density. They vary in other aspects too.
Troposphere: The lowest layer of the atmosphere having 75 percent of the gaseous particles. All-weather phenomena on the Earth occur in this sphere. The air is densest in this layer and its average thickness is 12 kilometers (16 km. in the equatorial region and 8 km in the polar region). Around three-fourths of the water vapor and dust particles of the atmosphere are found here. The atmospheric temperature is high at the lower level and it gradually decreases to the higher level and the temperature decreases 6.50 C. per kilometer. It is bounded on the top by a layer of air called the tropopause, which separates it from the Stratosphere. The tropopause is around 1.5 km thick and its temperature is -600 C
Stratosphere: It lies above the Troposphere, is the second major layer of the Earth’s atmosphere. As you go above the temperature rises in this layer and in the topmost part it becomes 00 Celsius. It is around 40 km. thick. The stratosphere is dry and the air contains little water vapor, so it is used as airways. It has a layer of ozone that protects life on Earth from the harmful ultraviolet rays of the sun. The upper part of this layer is called Stratopause, which separates the Mesosphere.
Mesosphere: It lies between the stratosphere and the thermosphere. The temperature in the mesosphere decreases with a height reaching about -1000 C in the upper mesosphere. This is the coldest region of the atmosphere. It is around 30 km thick. Its upper part is bounded by mesopause which is 80 km high from the earth's surface.
Thermosphere: It lies just above the mesosphere. It is extended up to 400 km. from the earth's surface. The temperature in the thermosphere increases with height. The thermosphere is also known as the heating sphere of the atmosphere and heat rises up to 16500 C. Electric ion is also found here. The radio wave sent from the earth's surface reflected from this layer.
Exosphere: It is the outermost layer of the atmosphere. This layer has the lightest gases like hydrogen and helium in extremely low densities. It extended from 400 km. to 10,000 km of the atmosphere. Air density is very low and heat rises up to 55500C. Most of the satellite orbit in this layer. In the exosphere Oxygen layer, the Helium layer, and the Hydrogen layers are found, where the Oxygen layer occupies the lower part and the Hydrogen layer is in the upper part.
Realms of the Earth: FAQs
1. What are the four main realms of the Earth?
The four main realms of the Earth are the geosphere, hydrosphere, atmosphere, and biosphere. The geosphere includes the solid earth, comprising rocks and minerals. The hydrosphere encompasses all water bodies, including oceans, rivers, lakes, and glaciers. The atmosphere is the layer of gases surrounding the Earth, essential for weather and climate. The biosphere consists of all living organisms and their interactions with the other realms.
2. How do the geosphere and hydrosphere interact?
The geosphere and hydrosphere interact in various ways. Water from the hydrosphere shapes the geosphere through processes like erosion, weathering, and sedimentation. Rivers carve valleys and transport sediments, while waves and currents shape coastal landscapes. In return, the geosphere influences the hydrosphere by determining the course of rivers, the formation of lakes, and the distribution of groundwater through aquifers.
3. What role does the atmosphere play in Earth's climate?
The atmosphere plays a crucial role in Earth's climate by regulating temperature, precipitation, and weather patterns. It contains gases like carbon dioxide and water vapor, which trap heat and create the greenhouse effect, keeping the Earth warm enough to support life. The atmosphere also drives the water cycle, influencing rainfall and evaporation, and distributes solar energy, impacting weather systems and climatic zones.
4. How does the biosphere depend on the other realms?
The biosphere relies on the geosphere, hydrosphere, and atmosphere for survival. Plants obtain nutrients from the soil (geosphere) and water from the hydrosphere, while animals depend on these plants for food. The atmosphere provides oxygen for respiration and carbon dioxide for photosynthesis. Additionally, the climate and weather patterns, governed by the atmosphere, affect the availability of water and suitable habitats, influencing the distribution and diversity of life.
5. What is the significance of the hydrosphere in supporting life?
The hydrosphere is vital for supporting life as it provides water, a crucial resource for all living organisms. Water is essential for metabolic processes, nutrient transport, and temperature regulation in living beings. Aquatic ecosystems, such as oceans, rivers, and lakes, are habitats for a diverse range of species. The hydrosphere also influences climate and weather, which in turn affects agricultural practices and freshwater availability.
6. How do human activities impact the realms of the Earth?
Human activities significantly impact the realms of the Earth. Deforestation, mining, and urbanization alter the geosphere by changing landforms and increasing soil erosion. Pollution from industrial activities contaminates the hydrosphere, affecting water quality and aquatic life. Emissions from vehicles and factories introduce greenhouse gases into the atmosphere, contributing to climate change. Habitat destruction and pollution negatively affect the biosphere, leading to loss of biodiversity and ecosystem services.
7. What is the importance of studying the realms of the Earth?
Studying the realms of the Earth is important for understanding the complex interactions that sustain life and maintain ecological balance. It helps scientists predict natural disasters, manage natural resources, and address environmental issues like climate change and pollution. Knowledge of these realms supports sustainable development practices, ensuring that human activities do not harm the environment and future generations.
8. How does the water cycle connect the different realms of the Earth?
The water cycle connects the different realms of the Earth by continuously moving water through the geosphere, hydrosphere, atmosphere, and biosphere. Water evaporates from the surface (hydrosphere) into the atmosphere, forms clouds, and precipitates back to the surface as rain or snow. This precipitation infiltrates the ground (geosphere) and is taken up by plants (biosphere), eventually returning to water bodies, completing the cycle. This process distributes water, supports life, and shapes landscapes.
9. What are the major components of the geosphere?
The major components of the geosphere include the Earth's crust, mantle, and core. The crust is the outermost layer, composed of solid rocks and minerals. The mantle lies beneath the crust, consisting of semi-solid rock that flows slowly. The core is divided into the solid inner core and the liquid outer core, primarily composed of iron and nickel. These components interact through geological processes like plate tectonics, volcanism, and earthquakes, shaping the Earth's surface.
10. How does climate change affect the biosphere?
Climate change affects the biosphere by altering habitats, disrupting ecosystems, and threatening biodiversity. Rising temperatures, changing precipitation patterns, and increased frequency of extreme weather events impact species' survival and distribution. Coral reefs, forests, and polar regions are particularly vulnerable. Climate change also affects food and water availability, influencing human health and livelihoods. Conservation efforts and sustainable practices are essential to mitigate these impacts and protect the biosphere. 0 0 0
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