Final Summary Discussion Earth Science Grade 11 2018-2019 Human Activities and Environment Gary Dean Anderson- a student at the University of Southern California who designed the universal recycling symbol during the conclusion of the first Earth Day in 1970. ENVIRONMENT- Refers to everything that surrounds a living organism which includes physical and biological factors. Provides services such as regulating, cultural, provisioning and supporting. Support services- cycling of vital nutrients. Ex. water, nitrogen, phosphorus carbon and oxygen cycle. Provisioning services- provides basic needs for survival. Ex. Air, water, shelter, food and energy in what way? Through the process of photosynthesis, food web and presence of forests, rivers and seas which can provide basic necessities. Regulating services- carbon sequestration (removal of carbon dioxide in the atmosphere and storage in plants. Cultural services- include non-material benefits that nature provides for human. Ex. Recreation, habitat. Human Activities, Waste and Waste Management Municipal waste - waste from households, commercial, establishments, institutions. Agricultural waste - farming and poultry (organic). Too much waste in the form of fertilizers is deposited into the bodies of water which can cause eutrophication (excessive richness of nutrients in a lake or other body of water, frequently due to runoff from the land, which causes a dense growth of plant life and death of animal life from lack of oxygen.) Industrial waste - Demolition waste is waste debris from destruction of buildings, roads, bridges, or other structures; scraps from manufacturing processes (unused papers) Mining waste - tailings (grinding and sorting of soil). Methods of Waste Disposal Landfill - cheapest and most convenient method. Every deposit of fresh garbage is covered with a layer of soil to prevent it from blowing around. But the threat of surface water and ground water reduces the use of this practice. Incineration - waste materials being treated is converted into gas, particles, heat. (it will lessen the waste but generates pollution. Mulch and compost - simplest method to dispose waste at home which is beneficial to plants. Source reduction - reusing materials Recycling - collecting throwaway materials and turning them into useful products. Exogenic Processes Sand Dunes – are normally associated with hot, dry dessert environment. Exogenic processes are interconnected with the atmosphere, hydrosphere, and biosphere, and includes the processes of weathering, erosion, transportation and deposition. Weathering- is the on-site breakdown of rock and its eventual transformation into sediments. It is an important process in the formation of soil. Mechanical weathering-is the physical breakdown of a rock into unconnected grains or chunks without changes in its composition: a. b. c. d. ExfoliationFrost wedgingRoot wedgingSalt wedging- Chemical weathering- occurs when there are chemical changes in the chemical changes of the rock. a. b. c. d. e. Dissolution – Hydrolysis – Oxidation – Hydration – Biological weathering – Erosion- is the separation and removal of weathered and unweathered rocks and soil from its substrate due to gravity or transporting agents like wind, ice, or water. Transport is the process by which sediments are moved along from the source to where they are deposited. Such as: a. Wind erosion b. Glacier c. Water a. Traction b. Saltation c. Suspension d. Solution Mass wasting – is the downslope movement of rock, soil and ice due to gravity. Factors that contribute to the occurrence of mass wasting are the following: 1. Relief – 2. Slope stability – 3. Fragmentation and weathering – Mass wasting can be classified in a number of ways such as type of material , type of motion, and speed of movement. 1. 2. 3. 4. 5. 6. Fall Topple Slide Spread Flow Complex The widely accepted classification of mass wasting is produced by Varnes in 1978 and modified by Cruden and Varnes in 1996. ENDOGENIC PROCESS Magma – the molten rocks that are found beneath the Earth’s surface. Most common component is silica (SiO2). The melting temperature of rocks could range from 800°C to 1400°C. Has the ability to flow because it is liquid. Volcano – a vent that serves as the conduit of lava or the molten rock that reaches Earth’s surface. The funnel-shaped depression where materials are ejected is called crater. The event when the lava (magma emerges at the surface) spews out of the volcano is called eruption. Various type of materials formed during volcanic eruption such as obsidian, pumice, Two types of eruptions: a. Effusive eruption – dominated by the flow of lava and formation of fountains and lakes. b. Explosive eruption – eject ash and larger fragments of broken up pyroclastic materials. Three different kinds of volcanoes a. Shield volcanoes b. Stratovolcanoes or composite volcanoes c. Cinder cone Earthquake – is a vibration in the surface of Earth resulting from the sudden release of energy. Fault- fracture on which one body of rock slides past another. Focus/hypocenter – place where rock ruptures and slips. Earthquake epicenter – the point at the surface directly above the focus. The energy released from the hypocenter of an earthquake travels as seismic waves. There are different kinds of seismic waves distinguished on where and how they move. Waves that travel within the interior of the Earth are called body waves. Primary waves or P-waves are body waves in which the particles of the material move back and forth parallel to the direction of wave motion. It is a compressional wave. Secondary waves or S-waves are body waves where the particles of the material move back and forth perpendicular to the direction of wave motion. They are also referred as shear waves. Waves that travel along the Earth’s surface is called surface waves. Rayleigh waves are surface waves that cause the ground to ripple up and down. Love waves are surface waves that cause the ground to move back and forth in a snake-like movement. Seismograph – The instrument that detects and records the ground motion from an earthquake and the record is called seismogram. The size of an earthquake is measured in two ways: Magnitude – the number that indicates the relative size of energy released in an earthquake. Intensity – is the amount of damage brought about by an earthquake. The first intensity scale Mercalli intensity scale developed by Giuseppe Mercalli in 1902. In the Philippines the PHIVOLCS Earthquake Intensity Scale developed by the Philippine Institute of Volcanology and Seismology is used in reporting earthquake intensities. Deformation - a process in which rocks change in shape, size, location , tilt or break due to squeezing, stretching or shearing. It is the dominant process in the formation of mountain belts. Stress - force applied per unit area. Three kinds of differential stress: a. Tensional stress b. Compressional stress c. Shear stress Strain - resulting change in the rocks due to the different types of stress.