Domains of envronment
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The document discusses the key domains that make up Earth's environment - the lithosphere, hydrosphere, atmosphere, and biosphere. It provides details on each domain, including the composition and layers of the lithosphere (crust, mantle, core), sources of freshwater and types of surface water in the hydrosphere, the structure and composition of Earth's atmosphere, and how the biosphere originated and evolved over billions of years to support life. Biosphere reserves that aim to protect ecosystems are also mentioned.
Domains of envronment
- 1. UNIT-3 ECOLOGY By: Aishwarya Assistant Professor CSE Department MITS Gwalior
- 2. DOMAINS OF ENVIRONMENT Lithosphere: The solid portion of the earth Atmosphere: The gaseous layers that surround the earth Hydrosphere: Water covers a very big area of the earth’s surface and this area is called the Hydrosphere Biosphere: It is the narrow zone where land, water and air together are found.
- 4. LITHOSPHERE The term was coined by JOSEPH BARRELL (1914). The lithosphere is a domain concerning land. When land is measured, it is measured by taking sea level as it’s base. The height of the land is also measured by denoting it as either ASL (Above Sea Level) or BSL (Below Sea Level). The Earth is divided into 7 continents. Asia, Europe, Africa, North America, South America, Antarctica, and Australia. Continents are the most important domain as they inhibit the largest number of life forms. Asia is the largest continent on Earth covering almost 1/3rd of the Earth’s land. Asia and Europe together form ‘Eurasia‘. It is followed by the continent of Africa. Africa is unique in its own way because it is the only continent through which the Equator, the Tropic of Cancer, and the Tropic of Capricorn pass through.
- 5. LITHOSPHERE Europe is located entirely in the Northern Hemisphere as well as some of it lies in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, and the Mediterranean Sea to the south. North America and South America together form ‘Americas’. North America is the third largest continent on Earth. Isthmus of Panama connects North America to South America. The Northern Hemisphere is also called the Land Hemisphere because the greater part of Earth’s landmass lies in the Northern Hemisphere. Australia also known as Oceania is an island continent surrounded by the Indian and Pacific oceans. It is known for its, the Great Barrier Reef, a vast interior desert wilderness called the Outback, and unique animal species like kangaroos and duck- billed platypuses which are found nowhere else.
- 6. LITHOSPHERE Antarctica is the southernmost continent and site of the South Pole, it is a virtually uninhabited and is in the completely ice-covered land. Australia and Antarctica entirely lie in the southern hemisphere.
- 7. LITHOSPHERE It is composed of crust & upper mantle which constitute the hard & rigid outer layer of the earth. It includes rocks and soil which is actual medium of growth of plants and animals and microorganisms .The lithosphere is thicker in continents than oceans floor.
- 8. LITHOSPHERE It consists of three main layers: Crust, Mantle, Core
- 9. LITHOSPHERE Crust: the crust is the outermost layer of the planet, the cooled and hardened part of the Earth that ranges in depth from approximately 5-70 km (~3-44 miles). Two types: Oceanic Crust :The bottom layer of this is composed of Silicon & Magnesium so its called as SIMA. It is thinnest layer. Its thickness is only 5-10km. Oceanic crust is made mostly of rocks with a composition of basalt ( a dark colored rock) Continental Crust: The uppermost layer of this is composed of Silicon & Aluminum so its called SIAl, which has a depth of about 32 to 40km. Continental crust is mostly made of rocks with composition of granite ( a light colored rocks).
- 10. LITHOSPHERE Mantle: It is It is the second layer of the earth and extends from 30km- 2900km with an average density of 2.7 g/cm3 It contains 83% of the total volume and 68% of the total mass of the earth. It is made up of silicate rich iron and magnesium and is divided from the crust by a discontinuity called as MOHOROVICIC DISCONTINUITY. Diamonds are tiny pieces of the mantle we can actually touch. Most form at depths above 200 kilometers (124 miles). But rare “super-deep” diamonds may have formed as far down as 700 kilometers (435 miles) below the surface. These crystals are then brought to the surface in volcanic rock known as kimberlite. The mantle’s outermost zone is relatively cool and rigid
- 11. LITHOSPHERE Core: It is the deepest layer of earth. It extends from a distance of 2900km – 6371 km with an average density of 4.3- 11 g/cm3. Mantle and core boundary is called as WEICHART- GUTENBERG Discontinuity. Core volume is 16% of earth’s total volume and core mass is 32% of earth’s total mass. It is further divided into 2 sub-zones by the discontinuity called as LEHMANN- BULLEN Discontinuity. • OUTER CORE: (2890km- 5150km) • INNER CORE: (5150km-6371km):
- 12. LITHOSPHERE Core: The inner core: This solid metal ball has a radius of 1,220 kilometers (758 miles), or about three- quarters that of the moon. It’s located some 6,400 to 5,180 kilometers (4,000 to 3,220 miles) beneath Earth’s surface. Extremely dense, it’s made mostly of iron and nickel. The inner core spins a bit faster than the rest of the planet. The outer core: This part of the core is also made from iron and nickel, just in liquid form. It sits some 5,180 to 2,880 kilometers (3,220 to 1,790 miles) below the surface. Heated largely by the radioactive decay of the elements uranium and thorium, this liquid churns in huge, turbulent currents.
- 13. HYDROSPHERE The domain of water is referred to as hydrosphere. It comprises various sources of water and different types of water bodies like rivers, lakes, seas, oceans, etc. It is essential for all living organisms. Water is the most abundant substance at the surface of Earth. About 1.4 billion cubic km (326 million cubic miles) of water in liquid and frozen form make up the oceans, lakes, streams, glaciers, and ground waters found there. It is this enormous volume of water, in its various manifestations, that forms the discontinuous layer, enclosing much of the terrestrial surface, known as the hydrosphere. Only 2.5% of Earths water is freshwater. And even in this 2.5%; approximately 69% is in the form of snow and ice.
- 14. HYDROSPHERE
- 15. HYDROSPHERE- FRESH WATER Fresh waters: Its about 97 percent of the earth’s water are stored in the earth’s oceans. All other waters that is fit for human consumption and agriculture is called fresh water. The basic source of fresh water is precipitation, but not all precipitation ends up as part of the freshwater supply. Water moving across the surface is called runoff. Runoff begins as rain accumulates in thin sheets of water that move across the surface of the land. These sheets collect into a small body of running water is called stream. A stream is defined as any body of water that is moving across the land
- 17. HYDROSPHERE- GROUND WATER Water that soaks into the ground moves down to a saturated zone where it is called groundwater. Groundwater moves through sediments and rocks beneath the surface, slowly moving downhill. An intermittent stream is one in which the source of groundwater is in low supply and flow only part of the time. The amount of rainfall that becomes runoff or groundwater depends on the following factors: 1. The type of soil in the surface 2. how dry the soil is 3. the amount and type of vegetation 4. the slope of the land 5. if the rainfall is a long, gentle one or a cloudburst
- 18. HYDROSPHERE- SURFACE WATER The land area drained by a stream is known as the stream’s drainage Waters basin or watershed. A line called divide separated two adjacent watersheds. A continental divide separated river systems that drain into opposite sides of a continent. A smaller body of standing water is called a pond, and one of much larger size is called a lake. A natural pond or lake created by building dam is called a reservoir.
- 20. HYDROSPHERE- SURFACE WATER It is used for: Water storage- A reservoir for water storage is kept as full as possible to store water. Flood control- A reservoir for flood control requires low water level in order to catch runoff, preventing waters from flooding the land. Generating electricity- A reservoir used to generate electricity requires the release of water from the reservoir. The water of streams, ponds, lakes and reservoirs are sources of fresh water and is collectively called surface water
- 21. HYDROSPHERE- OCEAN WATER Five Major Oceans in order of their size are Pacific Ocean: It is almost circular in shape. Asia, Australia, North and South Americas surround it. The Atlantic Ocean: It is the second-largest ocean in the world. It is ‘S’ shaped. It is flanked by the North and South Americas on the western side, and Europe and Africa on the eastern side. The Indian Ocean: It is the only ocean named after a country, that is, India. The shape of the ocean is almost triangular. In the north, it is bound by Asia, in the west by Africa and in the east by Australia. The Southern Ocean: It surrounds the continent of Antarctica The Arctic Ocean: It is located within the Arctic Circle and surrounds the North Pole. The Bering strait a narrow stretch of shallow water connects it with the Pacific Ocean.
- 22. Ocean Facts • The Pacific Ocean is the largest of the four main oceans • The Atlantic Ocean is the busiest ocean. Many ships cross the Atlantic, carrying cargo between the Americas, Africa, and Europe • The Arctic Ocean is the smallest and coldest ocean • The average temperature of all oceans is about 39 degrees F (3.8 degrees C) • Oceans are always moving • Tides change twice a day all over the world, as the oceans rise and fall along the shoreline. Scientists think this is caused by the pull of the sun and moon on our Earth, and the Earth's rotation. • Coral reefs are vast, rocky areas located in shallow, tropical waters. Coral reefs are like the tropical rain forest of the ocean in that the greatest variety of plant and animal life in the ocean live there. Coral reefs are formed from the bodies of small sea creatures called polyps • The world's oceans contain nearly 20 million tons of gold
- 23. ATMOSPHERE The earth is surrounded by a layer of gas called the atmosphere. The atmosphere extends up to a height of about 1,600 kilometres. The atmosphere is divided into five layers based on composition, temperature and other properties and they are: • the troposphere • the stratosphere • the mesosphere • the thermosphere • the exosphere About 99 per cent of clean and dry air in the atmosphere is composed mainly of nitrogen and oxygen. Nitrogen 78 per cent, oxygen 21 per cent and other gases like carbon dioxide, argon and others comprise 1 per cent by volume.
- 24. ATMOSPHERE
- 25. ATMOSPHERE Exosphere—contains few particles that move into and from space. Exobase—the lower boundary of the exosphere. Thermosphere—temperature increases with height. The temperatures can rise to 1,500 degrees Celsius, but it would not feel warm because of the low air pressure in this layer. mesopause—the boundary between the mesosphere and the thermosphere; the coldest place on Earth. mesosphere—the layer in which most meteors burn up after entering Earth’s atmosphere and before reaching Earth’s surface. stratopause—the boundary between the mesophere and the stratosphere. stratosphere—contains the ozone layer; the layer where volcanic gases can affect the climate. tropopause—the boundary between the stratosphere and troposphere. troposphere—the layer closest to Earth’s surface in which all weather occurs.
- 27. ATMOSPHERE LAYERS IN DETAILS The Troposphere: This is the lowest part of the atmosphere - the part we live in. It contains most of our weather - clouds, rain, snow. In this part of the atmosphere the temperature gets colder as the distance above the earth increases, by about 6.5°C per kilometre. The troposphere contains about 75% of all of the air in the atmosphere, and almost all of the water vapour (which forms clouds and rain). The Stratosphere: This extends upwards from the tropopause to about 50 km. It contains much of the ozone in the atmosphere. The increase in temperature with height occurs because of absorption of ultraviolet (UV) radiation from the sun by this ozone. Temperatures in the stratosphere are highest over the summer pole, and lowest over the winter pole
- 28. ATMOSPHERE LAYERS IN DETAILS By absorbing dangerous UV radiation, the ozone in the stratosphere protects us from skin cancer and other health damage. However chemicals (called CFCs or freons, and halons) which were once used in refrigerators, spray cans and fire extinguishers have reduced the amount of ozone in the stratosphere, particularly at polar latitudes, leading to the so-called "Antarctic ozone hole". The Mesosphere: The region above the stratosphere is called the mesosphere. Here the temperature again decreases with height, reaching a minimum of about - 90°C at the "mesopause".
- 29. ATMOSPHERE LAYERS IN DETAILS The Thermosphere and Ionosphere: The thermosphere lies above the mesopause, and is a region in which temperatures again increase with height. This temperature increase is caused by the absorption of energetic ultraviolet and X- Ray radiation from the sun. The region of the atmosphere above about 80 km is also caused the "ionosphere", since the energetic solar radiation knocks electrons off molecules and atoms, turning them into "ions" with a positive charge. The temperature of the thermosphere varies between night and day and between the seasons, as do the numbers of ions and electrons which are present. The Exosphere: The region above about 500 km is called the exosphere. It contains mainly oxygen and hydrogen atoms, but there are so few of them that they rarely collide - they follow "ballistic" trajectories under the influence of gravity, and some of them escape right out into space.
- 30. BIOSPHERE The biosphere is the narrow zone of contact between the land, water and air. It is the zone where life exists that makes this planet unique. The organisms in the biosphere are commonly divided into: • the plant kingdom • the animal kingdom The three domains of the earth interact with each other and affect each other in some way or the other. • Every living thing, every plant, every lake, and every desert is a part of it. It's pretty massive and pretty amazing. This is the largest category of organization for biologists. • It's different from the next level of ecological organization, the biome. The biosphere can be divided into several biomes. • These regions have specific climates, vegetation, animals, and adaptations necessary to survive in them
- 31. WHERE DID THE BIOSPHERE ORIGINATE? • The biosphere has existed for about 3.5 billion years. • The biosphere’s earliest life-forms, called prokaryotes, survived without oxygen. Ancient prokaryotes included single-celled organisms such as bacteria and archaea. • Some prokaryotes developed a unique chemical process. They were able to use sunlight to make simple sugars and oxygen out of water and carbon dioxide, a process called photosynthesis. • These photosynthetic organisms were so plentiful that they changed the biosphere. • Over a long period of time, the atmosphere developed a mix of oxygen and other gases that could sustain new forms of life.
- 32. WHERE DID THE BIOSPHERE ORIGINATE? • The addition of oxygen to the biosphere allowed more complex life-forms to evolve. Millions of different plants and other photosynthetic species developed. • Animals, which consume plants (and other animals) evolved. Bacteria and other organisms evolved to decompose, or break down, dead animals and plants. • The biosphere benefits from this food web. The remains of dead plants and animals release nutrients into the soil and ocean. These nutrients are re-absorbed by growing plants. This exchange of food and energy makes the biosphere a self- supporting and self-regulating system.
- 33. BIOSPHERE RESERVES • People play an important part in maintaining the flow of energy in the biosphere. • For example, in the atmosphere, oxygen levels decrease and carbon dioxide levels increase when people clear forests or burn fossil fuels such as coal and oil. • Oil spills and industrial wastes threaten life in the hydrosphere. • The future of the biosphere will depend on how people interact with other living things within the zone of life. • In the early 1970s, the United Nations established a project called Man and the Biosphere Programme (MAB), which promotes sustainable development. • Currently, there are 563 biosphere reserves all over the world. • The first biosphere reserve was established in Yangambi, Democratic Republic of Congo. Yangambi, in the fertile Congo River Basin, has 32,000 species of trees and such endemic species as forest elephants and red river hogs.
- 34. HOW DOES LIFE SUSTAIN ITSELF IN THE BIOSPHERE? • Scientists believe that the increase of atmospheric oxygen led to the evolution of the first forms of life. • Energy is needed for the function that organisms perform, such as growth, movement, waste removal and reproduction. It is the only requirement that living organisms in the biosphere need apart from what is there in the four major domains. • The source of this energy comes from the sun. Plants convert the sun’s energy into food and are very important to the biosphere.
- 35. WHAT PROCESSES OCCUR IN THE BIOSPHERE? The organisms in the biosphere are constantly involved in one or more of the following processes : • Decomposition : The breakdown of complex molecules—molecules of which dead organisms are composed – into simple nutrients that can be re-utilized by living organisms. • Energy : Power that can be used to perform work, such as solar energy. • Nutrient cycle : The cycling of biologically important elements from one molecular form to another and back to the original form. • Photosynthesis : Process in which plants capture light energy from the sun and use it to convert carbon dioxide and water into oxygen and organic molecules. • Respiration : Chemical reaction between organic molecules and oxygen that produces carbon dioxide, water, and energy.