The Lithosphere Unit 1 Part 1
The Scope of Earth Science • The field of Earth Science can be broken into four major areas of specialization: 1. Astronomy • Astronomers study the universe and everything in it, including Earth.. 2. Meteorology • Meteorologists study the forces and processes that cause the atmosphere to change to produce weather. • They also try to predict the weather.
The Scope of Earth Science 3.Geology • Geologists identify rocks, study glacial movements, interpret clues to Earth’s 4.6 billion-year history, and determine how forces change our planet, among many other things. 4. Oceanography • Oceanographers study the creatures and measure different physical and chemical properties of the oceans.
1. The Lithosphere • Includes the crust, continental crust and oceanic crust as well as the upper part of the mantle. 2. The Hydrosphere • About 97 percent of Earth’s water exists as salt water; the remaining 3 percent is freshwater contained in glaciers, in lakes and rivers, and beneath Earth’s surface as groundwater.
Earth’s Systems 3.The Atmosphere • Earth’s atmosphere is necessary for respiration by most living things, protects Earth’s inhabitants from harmful radiation from the Sun, and helps to keep the planet at a temperature suitable for life. 4. The Biosphere • Includes all organisms on Earth as well as the environments in which they live.
Example of Sphere Interactions • Humans (biosphere) built a dam out of rock materials (lithosphere). • Water in the lake (hydrosphere) seeps into the cliff walls behind the dam, becoming groundwater (lithosphere), or evaporating into the air (atmosphere). • Humans (biosphere) harness energy from the water (hydrosphere) by having it spin turbines (lithosphere, because the turbines come from metal ores in the ground) to produce electricity.
Weathering Earth/Environmental Science Ms. Frank
Weathering • Break up of rock due to exposure to the atmosphere • Surface Area Amount of surface exposed. • surface area, speed of weathering
Weathering • Physical (mechanical) Weathering – rock broken into smaller pieces • composition doesn’t change • The 4 main types are………..
1. Frost Wedging - freezing and thawing of water causes the rock to crack.
Physical Weathering • 2. Exfoliation rock layers get stripped away due to pressure. • Dome shaped
3. Thermal Expansion- • The daily changes in temperatures cause the rock to expand when hot and shrink when cold. • Occurs in deserts.
4. Organic Activity- The activities of living things that speed up the weathering process. http://facweb.bhc.edu/academics/science/harwoodr/GEOL101/Study/Images/D044-254.jpg
Chemical Weathering • Chemical Weathering – rock’s minerals are changed into different substance (Chemical Reaction) • Needs HEAT and WATER in order to occur. • 3 examples of chemical weathering
1. Oxidation– Oxygen added to some elements in rocks form oxides. • Example is rust www.stmarys.ca/.../ pubweather/chemcombined.html
2. Carbonic acid Carbon dioxide and water forms carbonic acid, which dissolves limestone.
Factors that effect the Rate of Weathering • Resistance • Some rocks are more resistant than others • Surface Area • Climate • Cold, Dry favors mechanical • Warm, Moist favors chemical
Let’s test ourselves • Take out a piece of paper and label 1-5.