Layers of the Atmosphere

1. WEATHER Weather patterns become evident when weather variables are observed, measured, and recorded.  These variables include air temperature; air pressure; moisture (relative humidity and dewpoint); precipitation (rain, snow, hail, sleet, etc.); wind speed and direction; and cloud cover. A cold front, shown on a weather map as a blue line with triangles, occurs when colder air advances toward warm air and forces the warm air out of the area Weather variables are measured using instruments such as thermometers, barometers, psychrometers, precipitation gauges, anemometers, and wind vanes. Layers of the Atmosphere Warm fronts form when lighter, warmer air advances over heavier, colder air.  A warm front is drawn on weather maps as a re line with red semicircles. A stationary front occurs when a boundary between air masses stops advancing.  Stationary fronts may remain in the same place for several days, producing light wind and precipitation.  A stationary front is drawn on a weather map as an alternating red and blue line.  Red semicircles point toward the cold air and blue triangles point toward the warm air. An occluded front involves three air masses of different temperatures-colder air, cool air, and warm air.  An occluded front may form when a cold air mass moves toward a cool air with warm air between the two.  The colder air forces the warm air upward, closing off the warm air from the surface.  Occluded fronts are shown on maps as purple lines with triangles and semicircles

2. The earth is divided into four main layers: the inner core, outer core, mantle, and crust. The core is composed mostly of iron (Fe) and is so hot that the outer core is molten, with about 10% sulphur (S). The inner core is under such extreme pressure that it remains solid. Most of the Earth's mass is in the mantle, which is composed of iron (Fe), magnesium (Mg), aluminum (Al), silicon (Si), and oxygen (O) silicate compounds. At over 1000 degrees C, the mantle is solid but can deform slowly in a plastic manner. The crust is much thinner than any of the other layers, and is composed of the least dense calcium (Ca) and sodium (Na) aluminum-silicate minerals. Being relatively cold, the crust is rocky and brittle, so it can fracture in earthquakes. Global winds A location's climate (long-term pattern of weather) is influenced by latitude, proximity to large bodies of water, ocean currents, prevailing winds, vegetation, elevation, and topography Sea breeze, land breeze Valley breeze, mountain breeze

3. Minerals and Rocks • *A mineral is a naturally occurring, inorganic solid that forms on or beneath Earth's surface. Almost all minerals have a crystal shape. Each mineral has a definite chemical composition. More than 3,000 minerals have been identified. • *Rocks are made up of a combination of minerals. Geologists classify rocks into three major groups: igneous rock, sedimentary rock, and metamorphic rock. The rocks in each group form through different steps in the rock cycle. • * Igneous rocks form from molten material deep inside Earth. The material slowly cools and hardens to form a rock. If the material cools slowly, large crystals form. If the material cools quickly, small crystals form. • * Sedimentary rocks are made from pieces of rocks that have been broken down by processes involving water and weather. The pieces are called sediment. Sediment can also contain remains of plants and animals. The sediment gets moved by water and wind and gets deposited in layers. Over millions of years, the sediments are squeezed together and become sedimentary rock. • * Metamorphic rocks form when rocks are exposed to a great increase in temperature and pressure. This occurs deep within Earth's interior where it is hotter and the overlying rock cause great pressure. Minerals may get changed to other minerals forming a new rock. Mineral grains also become aligned in response to the increased pressure. If the heat and pressure become too great, the rock melts and the rock cycle begin again. • * Minerals are the source of gemstones, metals, and other materials used to make many products. Gemstones are hard, colorful minerals that are used not only for jewelry but also for cutting, grinding and polishing. Minerals are used in foods, medicine, fertilizer, and building materials. Minerals are also the source of metals such as copper, iron, and silver. • * Today, people use rocks for building materials and in industrial processes. A rock that contains a metal or mineral that can be mined and sold for a profit is called an ore. To produce metal from ore, the ore must be mined, or removed from the ground. Then the ore must be processed to extract the metal. Mining is done in one of three ways. Strip mining removes the overlying layers of soil and rock to reveal the ore beneath. Open pit mining involves digging a huge pit to get to the ore. Shaft mining is used when the ore occurs in veins far beneath the surface. • The mined ore must be processed before it can be used. During smelting, the ore is mixed with other substances and then melted. The useful ore separates from the rest of the rock. The pure ore is removed. To make a metamorphic rock, you need:

4. Normal fault Reverse (thrust) fault Strike slip fault Convergent Boundary – where 2 plates collide – can cause folding (mountains) or REVERSE faults Divergent Boundary – where 2 plates pull apart – can cause DIP SLIP & NORMAL faults. Transform Boundary – where 2 plates slide past each other – can cause STRIKE SLIP fault. Subduction Zone – area where one plate slides under another plate and pushes magma up – volcanoes often form in these area.