Lesson 1.3 -1.4 earth_system.pptx.......

earth subsystem

1. Earth and earth’s subsystems

2. Objectives: Recognize the uniqueness of Earth being the only planet in the solar system with properties necessary to support life. Explain that the Earth consist of four subsystems, across whose boundaries matter and energy flow. Identify the layers of the Earth (crust, mantle, and core).

3. Earth Earth is the only planet in the solar system that can sustain life due to its characteristics.

4. Liquid water Life would not begun without water. The presence of water allowed the first photosynthetic organisms to thrive. Organisms such as cyanobacteria used sun light, carbon dioxide, and water to produce biomass and oxygen-an essential component of the atmosphere. The single –celled organisms which are present today. Scientists believe that water on earth came from two possible sources: water released through volcanism and water that came from the icy meteors of the outer regions of the solar systems that bombarded earth.

5. Heat source The heat that drives the different systems necessary to support life on earth comes from two sources: internal heating of earth and external heating from the sun. Heat coming from earth is caused by radiogenic heat from radioactive decay of materials in the core and mantle, and extruded via active tectonic activities, such as volcanism and plate movement. Heat provided by the sun is in the form of radiation which enters earth. As sunlight strikes earth, some of the heat is trapped by a layer of gases called atmosphere. The atmosphere is responsible for the occurrence of greenhouse phenomenon, a natural process which maintains heat.

6. Atmosphere having an atmosphere capable of providing heat like in a greenhouse, the atmosphere is therefore a vital part of photosynthesis. Photosynthesis ensures the adequate amount and flow of gases on earth- gases which are used by most organisms on the planet. Any planet devoid of an atmosphere would have an average surface temperature below freezing and would experience unpredictable and extreme weather and climates. It would also have an extreme amount of ultraviolet radiation because there is no atmosphere that absorbs radiation.

7. Characteristics of Earth to Sustain Life. Presence of water allowed first photosynthetic organisms to thrive. Sun provides heat from radiation, needed by plants to carry on with photosynthesis. Component of the Atmosphere consists different types of gases to support life.

8. The development of earth and earth’s System

9. Earth’s subsystems Hydrosphere Atmosphere Biosphere Geosphere

10. Each planetary body that was formed from the spinning solar nebula, now known to us as the sun, developed depending on its proximity from the sun and its interaction with the other nearby floating masses.

11. Shape of the earth Earth’s present shape is not a perfect sphere but an oblate spheroid. Earth got its present shape specially because of its gravity and rotation. As in other planets, gravity pulls the mass closer to its centre or its core. Isaac Newton actually predicted an almost similar shape to describe earth during his time. He based his assumption on earth’s daily rotation and on his studies of the other planets. Today, the study of earth’s shape is covered in the field of geodesy. It is now considered as an important branch of science in understanding satellites orbits creating navigational tools, and improving global positioning system (GPS) satellites.

12. Earth Subsystem Earth has a complex system composed of four subsystem- geosphere, hydrosphere, atmosphere, and biosphere- that interact to carry out many different natural process. These natural process (physical, chemical, and biological) are made possible by the composition and nature of the said subsystem.

13. geosphere refers to the solid Earth. The geosphere includes the rocks and minerals on Earth – from the molten rock and heavy metals in the deep interior of the planet to the sand on beaches and peaks of mountains. The geosphere also includes the abiotic (non-living) parts of soils, and the skeletons of animals that may become fossilized over geologic time .

14. geosphere The geosphere is the portion of earth that includes the interior structure, rocks and minerals, landforms, and all physical processes on land that shape earth’s surface. Scientists that study this part of earth are called Geologists. It should be clear that the term geosphere covers all of the solid parts of earth, from its surface up to the deepest depth of the core, as opposed the lithosphere that covers only the crust.

15. Layers of the Earth Crust Mantle Core

16. Earth’s internal structure The interior structure of earth is composed of different layers, each having unique features. There are three main layers of Earth: Crust, Mantle, and Core. the different layers of the geosphere vary in density, mineral composition, temperature, and thickness. Modern technology has allowed the identification of these materials in the interior of the earth through seismic waves. There are two types waves traveling through earth: p-waves, which t travel fast through both solid and liquids, and the I s-waves, which travel slower than p-waves and can travel only through solid.

17. Layers of the Earth: crust O utermost layer of the Earth. (Oceanic crust) relatively thin part which underlies the ocean basins. (Continental crust) relatively thick part that forms the large landmasses

18. Crust The crust consist of layer of oceanic and continental crust about 5 to 7o km in thickness. The continental crust is thicker than the oceanic crust. Most of crust is composed of eight elements, namely: Oxygen, silicon, aluminium, iron, calcium, sodium, potassium, and magnesium. Just above the upper mantle and still part of the crust is the Mohorovicic discontinuity or simply by the Moho. This layer was discovered by Croatian seismologist Adrija Mohorovicic (1857-1936)

19. Layers of the Earth: mantle L ongest part of Earth (2900 km.) made up of molten rocks called magma Lower (hot and exhibits plasticity) Upper (relatively rigid)

20. mantle B elow the crust is the mantle. However, trough recent studies, scientist added a sublayer of the mantle, known as the asthenosphere, that explain the occurrence of earthquakes and various seismic activities. The asthenosphere lies on the upper part of the mantle and is directly below the crust. The extreme temperature and pressure in the asthenosphere cause the rock to become ductile and thus, move like liquid. The mantle is made up of silicate rock. It is considered to be the thickest layer of earth as its hold 84% of the volume of the planet.

21. Gutenberg discontinuity Serve as the transitional boundary between the lower mantle and the outer core. It was named after Beno Gutenberg (1889-1960) who discovered it in 1913. tis boundary does not remain constant because of the changes in heat flow.

22. Layers of the Earth : core Composed of dense metals like Iron and Nickel The inner core (6000°C) (1250 km.) Outer core (4000 – 5000°C) (2300 km.)

23. Core The core is chiefly made up of iron and nickel. The iron is the outer core is in liquid form, which is why the outer core is known to be liquid while the inner core is solid. Iron is particularly important because this is the primary source of earth’s magnetic field. There also exist a transitional boundary between the inner core and the outer core. The Lehman discontinuity was discovered in 1929 when a large earthquake occurred in New Zeland . Inge Lehman- Danish seismologist studied the corresponding shock waves and realized that these waves had travelled some distance into the core bounced off to some kind of boundary.

24. Structure of the earth

25. Hydrosphere the totality of Earth’s water

26. Hydrosphere The hydrosphere encompasses all the waters found on earth. This includes water in various form (ice, liquid, or vapour) found on the surface of earth, below the surface of earth, and in the atmosphere (in gaseous form). Water covers about 70% of earth’s surface, and most of it is the water that makes up the oceans.

27. Importance of water Water has been associated with the existence of life. 1. Water could be in liquid, solid or gaseous form. 2. water has neutral pH. 3. water is a good conductor of heat and energy. 4. water has a high specific heat capacity. 5. water is the universal solvent.

28. The hydrological cycle Water moves through the hydrosphere in a cycle. Liquid water found on the surface of earth is converted to vapour as the temperature increases to bring water to its boiling point. Gaseous water is then collected in clouds and then falls back to the ground in the form of rain, hail, sleet, or snow depending on the temperature of the region where it fall. In these places, solid water will no longer melt but transform directly into gaseous form through precipitation to continue the cycle.

29. Distribution of water on earth All the waters found on earth are natural, but not everything is considered safe for drinking. Less than 3% of the world’s water is considered potable. Water on earth is divided on two groups : Surface water and ground water. Surface water, as the name implies, is water found on earth surface. Surface water may either be marine water or freshwater. G round water, is the water found beneath earth layer of water-bearing rocks is called an aquifer. An aquifer act as a reservoir for groundwater and may contain large amount of minerals like magnesium and calcium. If groundwater is used for drinking, distillation may be required to avoid possible effects on health.

30. The atmosphere The primitive atmosphere of earth is assumed to be similar to the composition of the solar nebula from which Earth came from. These last feature were then replaced by compounds released from the crust and from the impact of comets and other planetary objects which are rich in volatile materials.

31. Composition of atmosphere Earth’s atmosphere stretches from the surface of the planet up to as far as 10,000 kilometres (6,214 miles) above. After that, the atmosphere blends into space . While oxygen is necessary for most life on Earth, the majority of Earth’s atmosphere is not oxygen. Earth’s atmosphere is composed of about 78 percent nitrogen, 21 percent oxygen, 0.9 percent argon, and 0.1 percent other gases. Trace amounts of carbon dioxide, methane, water vapour, and neon are some of the other gases that make up the remaining 0.1 percent . The atmosphere is divided into five different layers, based on temperature.

32. Layers of the atmosphere The atmosphere is composed of various layers which differ in thickness, temperature, and density. These layer protect earth from many external threats in space, such as planetary debris, impact from celestial bodies, and radiation. The boundaries of the different layers of earth’s atmosphere were also established based on the temperature trends observed in each layers.

33. Troposphere This layer is considered to be the densest among the other layers. Air molecules travel up then back down causing the formation of clouds and eventually rain from moisture in the air. These variation give rise to weather. Prior to reaching the next layer above the troposphere is a thin buffer zone called tropopause.

34. Stratosphere The air in this layer has strong, steady horizontal wind which is advantageous to long-distance flight. At its upper region is the ozone layer which contain a high concentration of ozone. The ozone layers plays a very important role in absorbing the ultraviolet radiation from sun. With further studies, it was determined that certain sprays and chemical used in modern appliances use ozone-depleting substances (ODS) that directly destroy the ozone molecules in the ozone layers. The thin buffer zone exists before the next layer above the stratosphere. This zone called the stratopause .

35. mesosphere This is the layer above the stratosphere. The temperature here reaches a minimum of -90 °C and considered to be the coldest layer. The mesosphere is important in protecting earth from planetary debris. This is where most of the space rocks, like meteors, break down into smaller pieces such that by the time they reach earth, they are already in very small pieces. The thin buffer zone above the mesosphere is called the Mesopause . This zone is actually the coldest region of the atmosphere.

36. thermosphere This layer is the hottest layer because of its absorption of highly energetic solar heat. This extreme heat causes the atmospheric particles to become electrically charged, making it possible for radio waves to bounce off and be received beyond the horizon. The lower part of the thermosphere is the ionosphere where particles of oxygen and nitrogen are electrically charged by the solar wind. As the excited ion of oxygen and nitrogen go back to their neutral state, they released photons(light energy) which cause the spectacular display of colourful lights in the sky, called aurora. If witnessed in the northern regions such as the Artic or Northern Canada, it is called aurora borealis or northern lights. If seen in the southern regions such as Antarctica and Southern Australia, it called aurora australis or southern lights. There exist a thermopause above the thermosphere that also serve as a buffer zone which separates the thermosphere from outermost layer of the atmosphere.

37. exosphere The outermost layer of the atmosphere. It is located above the thermosphere where air is extremely thin and gradually fades into space.

38. biosphere Also called as “zone of life” because it contains the entirety of Earth’s living things. Includes all life forms even organic matter that has not yet decompose. It is also in this zone that the interaction between the different subsystems is most dynamic.

39. Biosphere The biosphere makes up all the living components on earth. It is the subsystem that comprises all living things, including those which have not yet been identified. In fact, there are more life-forms unknown to humans than those that have been already identified. Life exist in all the subsystems of Earth- on Land, in Water, and in air .

40. The origin of the biosphere Life on earth is presumed to have begun around 3.9 million years ago from a single primitive living creature. 1. The theory of the primordial soup - it state that life began from non-living matter like simple organic compounds. - It was believed that the primitive earth contained methane, water, ammonia, and hydrogen gas that accumulate in a “soup” at certain areas that are viable for energy transformation. - also known as the prebiotic soup or prebiotic chemistry hypothesis, is a scientific concept that proposes a scenario for the origin of life on Earth. This theory suggests that life arose from a "soup" of simple organic molecules in Earth's early oceans or other aqueous environments.

41. Deep- sea vent theory The deep-sea vent theory, also known as the hydrothermal vent hypothesis, is a scientific proposal that suggests life may have originated in the extreme environments of hydrothermal vents on the ocean floor. This theory challenges the traditional idea that life on Earth began in more benign surface conditions and instead posits that these high-temperature, high-pressure environments played a critical role in the origin of life.

42. Panspermia Panspermia is a scientific hypothesis that suggests life, or the organic building blocks of life, may exist throughout the universe and could be distributed by space dust, meteoroids, asteroids, comets, planetoids, or potentially by spacecraft in the form of unintended contamination by microorganisms. In essence, it proposes that life may not have originated independently on Earth but could have come from extra terrestrial sources.

43. The system of the biosphere The biosphere is a complex and interconnected system that encompasses all living organisms on Earth and their interactions with each other and with the physical environment. It is a critical component of the Earth's overall system, which includes the atmosphere, hydrosphere (water bodies), lithosphere (Earth's solid outer layer), and cryosphere (ice and frozen regions ). The biosphere is where certain organisms consume a different set of organisms to allow energy transfer from one group of organisms to another and allow certain materials to recycle.

44. The energy pyramid The energy pyramid, also known as an ecological pyramid or trophic pyramid, is a graphical representation used in ecology to illustrate the flow of energy through different trophic levels in an ecosystem. It helps visualize how energy is transferred from one level of organisms to another within a food chain or food web . Energy pyramids are a valuable tool for ecologists and environmental scientists to understand the dynamics of energy flow and the structure of ecosystems. They provide insights into how energy is allocated and transferred within ecological communities and help in studying the relationships between different species in an ecosystem.

45. Biosphere: the flow of matter Nitrogen Cycle Oxygen Cycle Carbon Cycle Water Cycle

46. Nitrogen Cycle T he series of the process by which nitrogen and its compounds are interconverted in the environment and in living organisms.

47. Nitrogen Cycle

48. Carbon and Oxygen cycle Carbon Cycle C arbon dioxide is fixed by photosynthetic organisms to form organic nutrients and is ultimately restored to the inorganic state (as by respiration, protoplasmic decay, or combustion). Oxygen Cycle A tmospheric oxygen is converted to carbon dioxide (CO 2 ) in animal respiration and regenerated by green plants in photosynthesis.

49. Carbon and Oxygen cycle

50. Water cycle C ontinuous process by which water is circulated through the Earth.

51. " The Earth system is not just a set of physical, chemical, and biological processes; it is a system that includes us, humans, as an integral and interactive part. We are not bystanders but active participants in the intricate web of life on this planet."

52. End of the lesson