Download presentation
Presentation is loading. Please wait.
Published byElizabeth Bates Modified over 9 years ago
1
The Dynamic Earth Chapter 3
2
Earth as a System Geosphere – land 6,378 km radius Atmosphere – mixture of gases, air Hydrosphere – water covers 2/3’s Biosphere – life exists, 9 km above to the bottom of the ocean
3
Earths Interior Each layer of the earth gets denser the deeper it gets Three Compositional Layers: 1. Crust – outer layer, 5-8km under the oceans, 20-70km under the continents 2. Mantle – 2900km thick, medium dense 64% 3. Core – radius of 3400 km, most dense
4
The Geosphere
5
Five Physical Layers of the Earth Lithosphere – cool, rigid layer, up to 300 km, makes up the pieces called the tectonic plates Asthenosphere – plastic, solid layer of mantle that flows smoothly and the tectonic plates move on top of it, 250 km Mesophere – lower part of the mantle, 2550 km Outer Core – made of liquid nickel and iron, 2200 km Inner Core – 1228 km, solid nickel and iron
6
Plate Tectonics Continents are on the tectonic plates and move with them Major tectonic plates are the Pacific, North American, South American, African, Eurasian and Antarctic Geologic activity occurs at the boundaries between tectonic plates Plates collide, pull apart, slip past each other cause mountains to form, earthquakes and volcanoes
7
Earthquakes Fault – break in the crust that is where earthquakes occur Richter scale 2-9.5- measure of the magnitude of an earthquake, each number is 31.7 times stronger than the number below Volcanoes Ring of Fire Contains 75% of the worlds active volcanoes Located on plate boundaries
9
Erosion Removal and transport of surface material 2 Types: Water Erosion – rivers and oceans Wind Erosion – deserts and beaches
10
Atmosphere - Mixture of gases surrounding earth Constantly changing Insulates thus keeping earth temperature constant Nitrogen makes up 78% O, Ar, Co 2, methane, water vapor Atmospheric Dust-soil, salt, ash from fires, volcanic ash, pollen, bacteria, viruses Air pressure is less dense the further out
11
Atmosphere – 4 layers 1.Troposphere – area closest to the ground, 18 km 75%of the gases, dust, ice and liquid water-Weather, Clouds, and smog occur here 1.Troposphere – area closest to the ground, 18 km 75%of the gases, dust, ice and liquid water-Weather, Clouds, and smog occur here 2. Stratosphere – 18-50 km Ozone layer, temperature rises 3. Mesosphere – 50-80 km, coldest layer, down to -92 o C 4. Thermosphere – contains the ionosphere where electrical charged particles are (get AM radio at night when sun goes down, particles quit jumping) Temperatures up to 2000 o C 2000 o C2000 o C
12
Energy Transfer occurs by: Radiation – electromagnetic waves, no contact but still feel it, moves from object with a higher temperature to one with a lower temperature Conduction – direct contact, fast moving molecules to slow moving molecules Convection – density differences, air is warmed, the air molecules move apart which increases the volume of air which reduces its density thus the air raises and causes a circular movement of air called a convection current
13
Green House Effect Solar energy is trapped next to the earth’s surface by the atmosphere Gases that trap heat next to earth are called greenhouse gases: water vapor, carbon dioxide, methane and nitrous oxide These gases keep earth warm enough to support life as we know it.
14
Water Cycle
15
Water on Earth Hydrosphere – all water on earth’s surface, covers 70% of earths surface, 97% salt water, of the remaining 3% - 2/3’s is frozen in the ice caps of the south and north poles Water Cycle – water constantly moves between the atmosphere and earth, sun provides the energy for this –Evaporation - Heat from sun cause water to evaporate into the atmosphere into water vapor –Condensation -Water vapor changes back into a liquid in the atmosphere as it cools, when it condenses it forms clouds –Precipitation – clouds cannot hold any more water vapor, it falls as rain, snow, hail, sleet rain is either absorbed by ground, runoff, or evaporates
16
Earth’s Oceans Make up over 70% of the earth’s surface Major Oceans: Pacific Ocean is the largest – deepest area of all ocean is Challenger Deep, 11,033 m below sea level, (deeper than Mt. Everest) Atlantic Ocean- also North and south Indian Ocean Arctic Ocean – smallest ocean covered by ice, pack ice
17
Ocean Water Salinity – concentration of all the dissolved salts, average 3.5% Composed of Sodium (31%) and Chlorine (55%) Zones of the Ocean Surface Zone – warm, sunlight Thermocline – area that gets cold Deep Zone – average temperature 2 o C Functions to absorb and store solar energy Currents move warm and cold water
18
Biosphere Closed system – matter in the environment Open system - for energy, sunlight
Similar presentations
© 2024 SlidePlayer.com Inc.
All rights reserved.