Waves, Ocean Currents, and El Nino

Waves

• Waves are the up and down movement of surface water.
• Waves carry energy, not water forward.
• Waves slow down as they approach shore where the water is shallow.
• The top of the wave gets ahead of the bottom, causing it to break.
• Waves are caused by wind pushing on the surface of the water.
• Waves erode rock and transport sand.
• Hurricane winds cause large waves that can lead to storm surges.
• Wave motion can be converted into electrical energy.

Ocean Currents

• Ocean currents are steady flows of water in a regular pattern.
• Steady winds, temperature, water salinity, and the shape of the ocean floor and shoreline drive ocean currents.
• The Gulf Stream is a warm Atlantic Ocean current that runs north along the eastern coast of North America.
• The Gulf Stream makes the weather in Europe warmer than other places at similar latitudes.
• A rip current is a flow of water moving away from the shore against incoming waves.

El Nino

• El Nino is a climate pattern in which water in the South Pacific gets unusually warm.
• El Nino disrupts normal weather patterns, causing extreme weather like droughts and floods.

Tides

• Tides are the cyclical rise and fall of ocean water levels.
• Tides are caused by the gravitational pull of the sun and moon on the Earth's oceans.
• The moon's gravity creates two bulges in Earth's oceans, leading to high tides.
• The areas between the bulges experience low tides.
• Spring tides occur when the sun, Earth, and moon are aligned, resulting in the highest high tides and lowest low tides.
• Neap tides occur when the sun, Earth, and moon are at a 90-degree angle, resulting in the smallest difference between high and low tides.

Changing Shorelines

• Shores are the land at the edge of the ocean.
• Waves and ocean currents carry sand to and from the shore.
• Wind causes rocks and cliffs to weather.
• Storms can erode beaches quickly.
• Beach restoration involves replacing and stabilizing sand, as well as building structures like jetties.
• Jetties are structures made of rock that prevent currents from moving sand, preserving beaches and keeping waterways open for boats.