8 Planets

Electromagnetic waves Produced by the movement of electrically charged particles Can travel in a “vacuum” (they do NOT need a medium Travel at the speed of light

Examples from Space!

Radio waves Longest wavelength EM waves Uses: –TV broadcasting –AM and FM broadcast radio –Avalanche beacons –Heart rate monitors –Cell phone communication

Microwaves Wavelengths from 1 mm- 1 m Uses: –Microwave ovens –Bluetooth headsets –Broadband Wireless Internet –Radar –GPS

Infrared Radiation Wavelengths in between microwaves and visible light Uses: –Night vision goggles –Remote controls –Heat-seeking missiles

Visible light Only type of EM wave able to be detected by the human eye Violet is the highest frequency light Red light is the lowest frequency light

Ultraviolet Shorter wavelengths than visible light Uses: –Black lights –Sterilizing medical equipment –Water disinfection –Security images on money

X-rays Tiny wavelength, high energy waves Uses: –Medical imaging –Airport security –Inspecting industrial welds

Gamma Rays Smallest wavelengths, highest energy EM waves Uses –Food irradiation –Cancer treatment –Treating wood flooring

Changes in the Earth over time

Weathering- the process of rocks being broken down into smaller pieces.

Two types of Weathering Mechanical Rocks break into smaller pieces by physical means – Water, ice, wind, gravity, organisms & changing temperatures Chemical Rocks break into smaller pieces by chemical reactions – Air, water, acid & salts react with minerals in rocks to form new substances

Erosion The movement of particles from one location to another is erosion Weathered particles of rock are transported by gravity, living organisms, water, glaciers & wind. Destructive

Deposition The settling (depositing) of eroded particles as sediments wherever they are transported by wind or water. Constructive

Rock Cycle

Plate Tectonics

Plate tectonics explains the movement of large sections of Earth’s crust called tectonic plates. The force behind tectonic plate movement is thought to be currents of magma flowing in Earth’s mantle.

What is Plate Tectonics The Earth’s crust and upper mantle are broken into sections called plates Plates move around on top of the mantle like rafts

Why do the plates move? 1.Due to tremendous heat, rock in the asthenosphere is like hot taffy 2.This allows plates to ride on top of hot, flowing rock. 3. Plates move because heat is being released from deep inside the earth. 4. Convection currents causes hot material to rise and expand (plates diverge) and cooler material to sink and contract (plates converge).

What is the Lithosphere? The crust and part of the upper mantle = lithosphere –100 km thick –Less dense than the material below it so it “floats”

What is the Asthenoshere? The plastic layer below the lithosphere = asthenosphere The plates of the lithosphere float on the asthenosphere

Plate boundaries Tectonic plates slowly collide against one another along plate boundaries. Sections of the plates may break off and be pushed down, up, or to the side. Mountain ranges, ocean trenches, earthquakes & volcanic activity are all common along plate boundaries. Pacific Plate is the largest

Convergent Boundaries Boundaries between two plates that are colliding   There are 3 types…

Type 1 Ocean plate colliding with a less dense continental plate Subduction Zone: where the more dense plate sinks under the less dense plate VOLCANOES occur at subduction zones

Andes Mountains, South America

Type 2 Ocean plate colliding with another ocean plate The more dense plate sinks under the more dense plate creating a subduction zone called a TRENCH

Type 3 A continental plate colliding with another continental plate Have Collision Zones: –a place where they are folded and thrust upward to form mountains.

Divergent Boundaries Boundary between two plates that are moving apart or rifting   RIFTING causes SEAFLOOR SPREADING

Features of Divergent Boundaries Mid-ocean ridges rift valleys fissure volcanoes

2 Types of Plates Ocean plates - plates below the oceans, which is more dense Continental plates - plates below the continents, which is less dense

Alfred Wegener

Alfred Wegener Wegener – proposed that in the distant past, the Earth’s continents were all joined as a single landmass. 1. Evidence for his theory a.South America and Africa would fit remarkably well, shoreline to shoreline. b.If the Americas were moved next to Africa and Europe, there would be a match of ancient continental rocks and tectonic (fold and fault) structures. c. Pangaea Pangaea – when Wegener placed all the continents together like a puzzle, it formed a large landmass which he called Pangaea.

Continental Drift – states that the continents have drifted and still are drifting apart. Strong support for this hypothesis comes from fossils found in South America and Africa which indicate that the regions had similar animal and plant life. And tropical fossils were found in Antarctica that existed around 200 million years ago. Plus, the contintents fit like puzzle pieces.

Fossil Evidence

All the land that drains into a specific body of water. Groundwater and surface water both contribute to the water in a watershed. Surface water becomes groundwater by soaking into the sand and soil or by traveling through cracks in rock.