Transcript File
The Lithosphere & the Hydrosphere The Lithosphere • Shell of the Earth - consists of the crust and the upper mantle. • Contains minerals and rocks. Important Sections for the Lithosphere 1. 2. 3. 4. 5. Minerals Rocks Soil Permafrost Energy Sources from the Earth 1. Minerals • Solid, inorganic substances with defined composition and properties. • Exist naturally. • Made of identical shaped crystals. Minerals are classified in 4 ways: 1. Colour a) idiochromatic, (always the same colour, like rubies). b) allochromatic, (can take on different colours, like quartz). 1. Minerals 1. Minerals 2. Transparency • Minerals can be transparent, (clear), translucent, (allow light to pass through), or opaque, (light cannot pass through). 3. Hardness • Hardness is evaluated using the Mohs Scale. A mineral of a certain hardness can scratch anything with a hardness that is lower. 1. Minerals 1. Minerals 4. Streak • When rubbed on porcelain, minerals leave a trace of powder. This is the streak. • The colour left depends on the type of mineral. 1. Mining of Minerals • Minerals in their raw state is called ore. Ore is extracted from the lithosphere, (rock containing mineral), then separated from the rock. 2. Rocks • Rocks are heterogeneous solids composed of many minerals. Unlike minerals, composition of rocks is not clearly defined. • Can be used for decoration, building, insulation, etc. • There are three types of rock: 1. Igneous 2. Sedimentary 3. Metamorphic 2. Igneous Rock • Formed when magma cools and solidifies. • There are two types: Intrusive and Extrusive. 2. Sedimentary Rock • Formed by the accumulation and compression of debris over many years. • These rocks are formed at the Earth’s surface or on the surface of the ocean floor and show visible layers. 2. Metamorphic Rock • These originate as either Igneous or Sedimentary rocks that become transformed by intense heat or pressure over millions of years. 3. Soil • Soil is formed from parent rock, a layer of rock beneath the Earth’s surface. • The parent rock breaks down over time, due to frost, wind, rain, and the freeze-thaw cycle and mixes with decomposing organic matter to form soil. • As soil develops, it forms distinct layers, called horizons. 3. 5 Soil Horizons, (layers) 1. 2. 3. 4. 5. Organic matter, (decomposing plants and animals, called humus). Topsoil, (humus and minerals, supports plant life). Subsoil, (small mineral particles, trees get nutrients here). Fragmented parent rock, (chunks of rock formed from layer below). Unaltered parent rock, (starting point for soil formation). 3. Fertility of Soil Depends on… 1. Presence of minerals, (nutrients for vegetation). 2. Adequate moisture, (can hold onto moisture). 3. Appropriate pH, (soil that is too acidic or alkaline is not healthy for vegetation). 4. Permafrost • In northern regions, large expanses of soil are permanently frozen, even in Summer. This type of ground is called permafrost. • For ground to be classified as such, it needs to be at a temperature of 0°C for at least two years. • Around 50% of Canadian soil is permafrost. • Permafrost is not limited to polar regions, but can be found in areas of high altitude, like mountain peaks. 4. Permafrost • In certain regions, the upper layer of permafrost will thaw in the Summer. This is called the active layer. 5. Sources of Energy in the Lithosphere 1. Fossil Fuels • Result from the transformation of organic matter that accumulated millions of years ago. Pressure caused the organic matter to be transformed to fossil fuels. • Coal, natural gas and oil are fossil fuels. • Natural gas and oil result from marine organisms. – Accumulate on the sea floor and become covered in sand and silt. 5. Sources of Energy in the Lithosphere • Coal is formed from trees and other terrestrial organisms that once grew in swamps. Over time they were buried and compressed. • When fossil fuels are burned, they produce CO2 and CH4. 5. Sources of Energy in the Lithosphere 2. Uranium • A radioactive element found naturally in the Earth’s crust. • Splitting its atom, (fission), allows a huge output of energy, (one handful provides as much energy as 70 tonnes of coal). • Nuclear reactors needs to cool waste and then bury it. • Risk of accidents is a constant concern due to the radioactivity. 5. Sources of Energy in the Lithosphere 3. Geothermal Energy • Uses the internal heat of the Earth by sending a fluid deep underground to be heated. The fluid returns to the surface, hot enough to be converted to electrical energy. • Used mostly in volcanic regions of the world, where the crust is thinner. No fluid is needed. SECTION #2 - THE HYDROSPHERE The Hydrosphere • Outer layer of water on Earth, which includes all states of water: liquid, solid and gas. Important Sections for the Hydrosphere 1. 2. 3. 4. Inland Waters & Watersheds Oceans The Cryosphere, (frozen water) Energy from the Hydrosphere 1. Inland Waters and Watersheds • Inland waters are fresh water, includes lakes, rivers and groundwater. • Watersheds are areas where inland waters drain into the same larger body of water. – Watersheds are sometimes called Catchment Area. • Water flow is influenced by topography, geology, climate, vegetation, development. • Quebec has two main watersheds. 2. Oceans • There are five oceans: Pacific, Atlantic, Indian, Arctic and Southern, (Antarctic). • Oceans temperatures are determined by: a) Depth: below 200m temperature drops drastically, (called thermocline zone – some sunlight, but vert little). b) Seasons c) Latitude, (warmer around equator). 2. Oceans • Ocean circulation is caused by ocean currents. a) Surface currents are caused by wind, and move horizontally. b) Subsurface currents caused by density of the water and salinity (colder and saltier=more dense) c) Thermohaline circulation is the combination of both, (conveyor belt responsible for regulating global climate). Ocean currents bring warm an cold air with them. 2. Oceans • All bodies of water have a certain salinity. – Percentage of dissolved salts in a solution. • Based on salinity, water can be classified. Type of Water Fresh Water Ex - Lakes, rivers, streams, etc. Brackish Water Where fresh water meets saline water Ex – Estuaries, certain seas Saline Water Oceans, seas, etc. Brine High concentrations of salt in solution. Ex – Dead Sea, Great Salt Lake Salinity Less than 0.05% 0.05% - 3% 3% - 5% More than 5% 3. The Cryosphere (Frozen Water) • The cryosphere consists of glaciers, pack ice, frozen lakes and river, etc. 1. Pack Ice • • Ice floating on the oceans near the North and South poles Global warming has caused Arctic ice pack to shrink significantly 3. The Cryosphere (Frozen Water) 2. Glaciers • Masses of ice on land. • When chunks break off and fall into the sea they create icebergs. • This causes a rise in sea level, just like ice cubes in your drink does. • When ice melts, salinity is affected and water becomes less dense. This could have an impact on ocean currents and therefore global climate. 4. Energy Resources of the Hydrosphere • The movement of water, (usually rivers and waterfalls), provides an immense source of energy. • Transforming it into electricity can be challenging because it requires large facilities. • Hydraulic energy is derived from moving water. • Hydraulic energy is renewable, and no greenhouse gases are emitted, but cause severe damage to ecosystems.