3-5 Waves (Earth Book)

How Waves Form Energy in waves comes from wind that blows across the water’s surface!

Wave MotionWave Motion 2

1.As the wind makes contact with the water, some of its energy transfers to the water 2.Water particles move up and down, NOT forward; the form of the wave moves forward 3.As wave approaches land, the water particles DO move forward 4.Forward-moving water shapes the coast

Erosion by Waves

Impact Energy in waves can break apart rocks & make cracks larger

Abrasion As a wave approaches shallow water, it picks up sediment, when the wave hits land, the sediment wears away rock like sand paper

Landforms created by Wave Erosion

Wave-cut cliff Waves erode base of the land so much that the rock above collapses

Part of the shore that sticks out into the ocean Headland

Waves coming to shore change direction & bend to concentrate their energy on the headland Eventually wears it down & evens out the shore

Sea Cave When a soft pocket of rock surrounded by harder rock is hollowed out by wave erosion, usually in a headland

Inside a Sea Cave

Sea Arch When a soft pocket of rock is hollowed right through a headland to the other side, usually a sea arch is created from a sea cave

Sea Stack When the top of a sea arch collapses, a pillar of rock is left behind

Sea Stack Wave cut notch Sea Arch Sea Cave Headland

Deposition by Waves

Beach An area of wave-washed sediment along a coast. Sediment usually sand from rivers, but also coral or seashell bits

Longshore Drift Waves coming into a beach come in at an angle not straight on

Creates a current that is parallel to shore. Waves Current That’s why they say if you get stuck in the “under toe” swim parallel to shore

Longshore Drift Sediment build-up Moves sediment down a beach in the direction of the current

Spit forms Current A beach that projects from the shore like a finger as longshore drift carries sediments down a beach, the sediments get deposited when they run into a headland or other obstacle Spit

Sandbar Long ridges of sand parallel to the shore Built up by incoming waves

Barrier Beach Similar to a sandbar Formed when storm waves pile sand above sea level Dangerous to live on-can be swept away by a storm

2-3 Winds (Weather Book)

What is Wind? Horizontal movement of air from an area of high pressure (H) to an area of lower pressure (L) The greater the difference, the faster the wind moves Differences in air pressure are caused by the uneven heating of Earth Described by direction coming from & speed

What is Wind?

LOCAL WINDS Move short distances Can blow in any direction Caused by unequal heating of Earth’s surface within a small area

SEA BREEZE Land heats up fast during day (low pressure) Ocean stays cool (high pressure) Uneven heating creates wind HLHL Ocean  Land Air moves from the ocean to the land creating a sea breeze

SEA BREEZE

LAND BREEZE Land cools down colder than ocean at night (high pressure) Ocean stays warmer than land (low pressure) Uneven heating creates wind HLHL Land  Ocean Air moves from the land to the ocean creating a land breeze

LAND BREEZE

GLOBAL WINDS Winds that blow steadily from specific directions over long distances Caused by unequal heating of Earth’s surface over large areas

On a hypothetical non-rotating planet, 2 large wind currents would form. Non-Rotating Earth Model Northern Hemisphere & Southern Hemisphere

Non-Rotating Earth Model

Pause here for Coriolis paper test

Coriolis Effect As Earth rotates, the Coriolis Effect turns winds in the Northern Hemisphere toward the right. Rotation of earth

Coriolis Effect

Rotating Earth Model When the effect of rotation is added, the 2 cells would break into many smaller cells (wind belts).

Global Wind Belts A series of wind belts circle Earth. Between the wind belts are calm areas where air is rising or falling.

Global Wind Belts: 1.Doldrums & Horse Latitudes– very weak winds, almost no winds, located at: 0 0 (doldrums) and 30 0 (horse latitudes) 2.Trade Winds–Winds are very calm, warm and steady. Located 0 0 to 30 0 N & 30 0 S of the equator 3.Prevailing Westerlies –Travel west to east. Strong winds located latitude in both hemispheres. 4.Polar Easterlies – Cold, but weak winds Located 60 0 to the poles 5. Jet stream – Strong, belt of high-speed, high- pressured winds. Blow from west to east.

3-6 Wind (Earth Book)

Weakest agent of erosion Shapes land in areas with few plants to hold soil in place WIND EROSION

DEFLATIONDEFLATION Process by which wind removes surface materials

DEFLATIONDEFLATION Fine particles- carried through the air (clay & silt) Medium particles-skip, bounce or jump (sand) Large particles-slide or roll (pebbles & rocks)

Desert Pavement When all the smaller sediments (clay, silt, sand) are removed and only larger rocky materials too heavy or large to move remain

Blowout Slight depression in the ground, deflation can create a bowl-shaped hollow

WIND DEPOSITION When wind slows down or hits an obstacle, sediments are dropped (deposited) The stick in the picture acts as a wind obstacle. It lowers the wind speed and allows for sand to build up behind the stick.

Beach Sand Dune

Desert Sand Dune

Sand Dune Coarse wind-blown sediment that has built up Happens when wind hits an obstacle (clump of grass/rock) Seen on beaches and in deserts Many shapes and sizes Move over time shifting from one side to another Plant roots can anchor a dune (help keep it in place)

Loess deposit layer Fine, wind deposited sediments Clay or silt Deposited in layers Can travel far from source Help form fertile soil (valuable farm land)

Major loess deposits in the U.S.