The Lithosphere Ooooh! Exciting
The Four Spheres Strahler, A. and Strahler, A., 2005. Physical Geography. Wiley, NY.
The Lithosphere • http://www.pbs.org/wnet/savageearth/animations/hellscrust/index.html • The earth is composed of 3 parts • The core • The mantle • The crust • The Lithosphere is the hard shell of the earth consisting of the crust and the top most part of the mantle
The Lithosphere Similarities with an Apple Parts of the earth
The Lithosphere • The Lithosphere contains minerals and rocks that we use for buildings, metals and jewellery.
Minerals • Minerals are inorganic ( they do not originate from neither plants nor animals) • Minerals must exist naturally on earth; they cannot be manufactured • Minerals have a clearly ordered structure • Minerals are distinct in their chemical composition • Some minerals are made up of one element ex: gold (Au), copper (Cu) • Some minerals are made up of 2 or more elements bonded together ex: Quartz (Si O2)
Classification – Color and Transparency • Idiochromatic minerals are minerals that have a characteristic colour. The element that gives them their colour is part of their chemical composition • Minerals that vary in color are allochromatic • Minerals can allow light to pass through, some straight through= transparent. • Some let some light through= translucent • Allowing no rays of light through= opaque
Hardness • Hardness depends on the strength of the atomic bonds in the minerals • Mohs scale assigns a value from 1-10 to indicate its hardness
Streak • When rubbed minerals leave a trace of powder • The color may be different from that of the mineral • Idiochromatic leave bright colored powder • Allochromatic leave a white/pale powder
Types of Rocks • There are three main types of rocks: http://www.youtube.com/watch?v=Aqy-p41VpKU&feature=related • Igneous - formed when molten rock cools. • Sedimentary – formed by the “cementing together” of small grains of sediment. • Metamorphic – rocks changed by the effect of heat and pressure.
volcano magma Igneous Rocks • These are rocks formed by the cooling of molten rock (magma.) Magma cools and solidifies forming igneous rocks
Igneous Rocks • There are 2 types of Igneous rock • Extrusive Igneous Rocks: Rock forming from Magma upon contact with air 2) Intrusive Igneous Rocks: Rock forming from Magma before reaching the surface of the earth
Fragments washed to the sea Rocks are broken up by the action of weather sea Sedimentary rocks Getting older Sedimentary Rocks • Sedimentary Rocks are rocks formed when particles of sediment build up and are “cemented together” by the effect of pressure and minerals.
Pressure from surface rocks metamorphic rock forming here Magma heat Metamorphic Rocks • Metamorphic rocks are formed by the effect of heat and pressure on existing rocks. • This can greatly affect the hardness, texture or layer patterns of the rocks.
How Granite is made? http://www.youtube.com/watch?v=z66fR9p4Lgc How curling stones are made • http://www.youtube.com/watch?v=nxrt3fjp4t0
Soil • Soil is from parent rock • It takes 200 years to form a layer of soil...1cm thick! • Soil forms distinct layers over time. • Layers can be distinguished by color, texture and composition • The layers are called HORIZONS
O horizon – Organic Matter • Topmost layer • High % of dead organic matter. • Ie: leaves, stems, fruits, seeds, pine needles • Formed from decomposition of organic matter. (humus)
A horizon - Topsoil Seeds germinate and plant roots grow in this dark-colored layer. It is made up of humus (decomposed organic matter) mixed with mineral particles. Mixture of soil from below and the humus above.
B horizon - Subsoil • Trees with deep roots draw nutrients from this layer • It is made up mostly of sand and silt, having lost most of its minerals and clay as water drips through the soil. • Leached from layers above • Clay and many minerals • Iron • Aluminum • Calcium
C horizon – Fragmented Parent Rock • Can be saturated in groundwater • Formed through the disintegration of the underlying parent rock. • It consists of slightly broken-up bedrock.
R Horizon – Unaltered Parent Rock • Plant roots do not penetrate into this layer. Starting point for soil formation
Soil Conditions • Three conditions must be met for soil to be suitable for plant life to form: • Water soluble nutrients • Adequate moisture • Appropriate soil pH • Soil to acidic or alkaline jeopardizes the transfer of mineral nutrients
Permafrost • Ground whose temperature has been 0o or lower for at least two years.
Permafrost • The upper layer thaws in the summer and some growing occurs, this layer is the active layer • Permafrost makes construction difficult and agriculture nearly impossible • Inuit people build their homes on piles that pass through the active layer and sit directly on the permafrost
Soil Texture • Soil texture is the single most important physical property of the soil. Knowing the soil texture alone will provide information about: 1) water flow potential, 2) water holding capacity, 3) fertility potential, 4) suitability for many urban uses like bearing capacity
To determine texture • The Percent of sand, silt, clay in a soil sample • Critical for understanding soil behavior and management • Soil texture is not subject to change in the field but can be changed in potting mixes.
Buffering Capacity • pH is measured on a scale of 0 (very acidic)-14(very alkaline) • Soil should ideally be between 6-7 to allow for maximum nutrient absorption • Soil has the ability to resist pH changes, when acidic or alkaline compounds are added this is it`s BUFFERING CAPACITY
Energy Resources in The Lithosphere • The lithosphere contains energy resources • Oil • Natural Gas • Coal • Thanks to these resources, we can heat buildings, power factories and car engines
Fossil Fuels • 2/3 of the world’s energy is is produced from fossil fuels (oil, natural gas and coal) • http://www.brainpop.com/science/ourfragileenvironment/fossilfuels/ • http://videos.howstuffworks.com/hsw/6187-energy-what-are-fossil-fuels-video.htm
Oil comes from Small Marine Mammals and algae Organisms sink to the bottom where they are covered in sand, rocks and minerals Due to the pressure the sediment is turned into oil Formation of Oil & Natural Gas
Oil comes from plants and trees that once grew in swamps Over time these swamps were buried under sand and rock The organic residue was compressed and it turned into coal Coal is a solid Formation of Coal
Fossil Fuels • When fossil fuels burn they give off by- products like carbon dioxide • Carbon dioxide is the main greenhouse gas behind global warming • Sulfur dioxide and nitrogen oxide are also by-products of the combustion of fossil fuels and cause acid rain
Energy Resources: Uranium • Uranium is a radioactive element that is found naturally in the earth’s crust • By splitting the nucleus of the Uranium atom energy is produced called NUCLEAR ENERGY
Pros to Nuclear Energy • Little waste produced • A lot of energy can be produced with very little uranium
Cons to Nuclear Energy • No where to store it • It’s radioactive (waste)... That it can alter DNA
Energy Resources: Geothermic • Molten Rock is found beneath the Earth’s crust which contains lots of energy • Geothermal Energy is the energy that comes from the internal heat of the earth. • http://www.youtube.com/watch?v=-ajqiPe_9Ko&feature=related
How does it work? • http://www.youtube.com/watch?v=-ajqiPe_9Ko&feature=related Series of pipes under house Heat absorbing liquid in pipes When it’s cold in the air, heat will be transported to house from pipes (underground) When it’s hot in the house, heat will be transported to the pipes
Geothermal Pros and Cons • Pros • Reduce heating costs • Reduce CO 2 emissions • Renewable energy source • Cons • Expensive