CHAP 18 EARTHS CYCLES 2 THE ATMOSPHERIC CYCLE

CHAP. 18: EARTH’S CYCLES (2). THE ATMOSPHERIC CYCLE Circulation of gases near Earth’s surface. • Weather and climate are about Air Masses. • Air Mass – Regions of the atmosphere with the same properties (temperature, pressure, humidity). • Weather – The state of the atmosphere at a given time and place. • Climate - A long-term average of weather for a given region. • Dry climates are hot with little precipitation (deserts or grasslands). • Tropical climates are hot with lots of precipitation (rainforests).

OUR ATMOSPHERE • Exosphere - Molecules from atmosphere escape into space; satellites orbit here. • Thermosphere - High energy rays from the sun are absorbed; hottest layer. • Mesosphere - Most meteorites burn up here. • Stratosphere - 19% of the atmosphere’s gases are here; ozone layer is here. • Troposphere – Where our weather occurs.

COMMON STORMS • Tropical storms: Start as low-pressure areas over warm ocean water. • Draw energy from the warm water. • Grow and rotate in great spinning patterns. • Hurricanes - Begin in the Atlantic Ocean off the coast of Africa, or in the Caribbean. • In the Pacific were once called Typhoons. They are often now called Hurricanes. • Tornadoes - Rotating air funnels, tens to hundreds of meters across. (1) Descend from storm clouds to the ground. (2) Cause intense damage where the funnel touches the ground.

The Rock Cycle • Process by which rock is created, eroded, and changed. Granite Pumice • Rock formations - Bodies of rock that form as a continuous unit. “Reservoirs” of the rock cycle. Limestone • Three types of rocks. (1) Igneous - Solidify from a hot liquid. (2) The first solids to appear on Earth’s surface. Sandstone (2) Sedimentary - Made up of grains of material worn-off previous rocks. (2) (3) Metamorphic - Changed by Earth’s extreme conditions of heat and pressure. (2) Marble Slate

THE ROCK CYCLE ST AR How it starts: NG TS AG LI AIN 1. Melted rock O CO 6. Melts again to (Magma, Lava) form Magma/Lava Igneous Rock N EL SIO O R M 3. Erosion TI N G 2. Cools to form E breaks it down pressure forms Metamorphic Rock to form sediment 5. Heat and CO MP AC RE TE D U ESS PR & AT HE 4. Sediment compacts as Sedimentary Rock

QUIZ TIME • What this chapter was all about. Earth’s 3 great cycles • The state of the atmosphere at a given time and place. Weather • Regions of the atmosphere with the same properties. Air • State of the atmosphere over a long time period. Masses Climate • Rotating air funnels, 10’s to 100’s of meters across. Tornadoes • Hottest layer of the atmosphere. Thermosphere • Start as low pressure areas over warm ocean water. Tropical Storms • Igneous, Sedimentary, Metamorphic. 3 types of rocks • WORD BANK Climate • Rock Cycle • Tropical Storms • Aquifers • 3 types of rocks • Thermosphere • Earth’s 3 great cycles • Air Masses • Tornadoes • Weather • Climate • Process by which rock is created, eroded, and changed. Rock Cycle