WAVES and TIDES Section 2.3 page 64

WAVES Large ripples set in motion by steady winds Waves on the surface of water are the result of a transfer of energy from moving air to the water Rogue Wave

Common Wave Features: As a wave approaches a shoreline, the wavelength decreases and the wave height INCREASES

CREST – Highest part of the Wave TROUGH – Lowest part of the Wave AMPLITUDE – Distance from the rest position to the Trough or Crest WAVELENGTH – Distance from one Crest to the next

Types of WAVES SWELLS Smooth waves caused by wind and storms far out in the ocean BREAKERS The tumble of water when a wave collapses onshore

TSUNAMIS Giant waves that can be sent in motion by earthquakes on the ocean floor, landslides or volcanic eruptions near the shoreline. Tsunamis can be very destructive. There was a Tsunamis on November 18 th, 1929 off the South Coast of NL

Shaping Our Shorelines… page 66 Waves have the power to erode and deposit sediments on the shore. As rocks are rubbed against each other in surging water, rock fragments are smoothed and ground down into smaller pebbles and grains of sand. Tides work with Waves and determine the shoreline.

The Shaping ProcessWEATHERING EROSION DEPOSITION The break down of rocks into smaller particles The movement of those weathered particles When eroded material is dropped or left behind Video: Weathering and Erosion

Factors that affect the interaction of WAVES and TIDES on the SHORELINE are: Slope of the shoreline Shape of the shoreline Type of ROCK material Wave energy

Through Weathering, Erosion and Deposition, Waves and Tides Can Create: 1.BEACHES Sandy Beaches are formed on shorelines with GENTLER SLOPE and calm waters. Smaller rock fragments can settle and build up ROCKY BEACHES – occurs along steeply sloping shorelines. Rock Fragments are washed back to the sea, leaving the shoreline with bare rock, boulders and larger stone.

2. SANDBARS OR SHOAlS – occur where a stream, river or ocean current cause a build up of sand resulting in a shallowing of the water. When waves move towards a beach, they slow down, their wave HEIGHT INCREASES and the WAVELENGTH DECREASES. This is called SHOALING

Wave Energy is concentrated on headlands and spreads out as it reaches bays. Bays are located between 2 headlands 3. HEADLANDS and BAYS

4. Sea Caves – occur when waves erode a cave in to the rock 5. Sea Arches - when caves increase inside and meet, an arch can be formed 6. Sea Stacks – when erosion causes a piece of rocky land to be cut off from the rest of the land

Tides page 69 The slow RISE and fall of the ocean The upper and lower edges of a beach are determined by the HIGH and low tide mark Tides are connected to the motion of the MOON and the spinning of the EARTH The moon exerts a GREATER force of pull than the sun due to its closer proximity to Earth

Water ‘bulges’ on the same side and the opposite side of the Earth to the Moon How Do Tides Work? video

2 Types of TidesTypes of Tides 1. Spring Tide Occurs when the Earth, Sun and Moon are in a line. Causes extra high and low tides. Occurs during Full and Half moons

Occur when the Sun and the Moon are at right angles to one another. Causes the smallest tidal movements. There is little difference between low and high tides. Occurs at QUARTER MOONS 2. Neap Tides

Tidal Range: The difference in level between a high and a low tide.

Check Your Understanding Questions page 77 # 1-3,6,7,9,10