Focus on Tides Objectives: Students will learn what causes tides. The difference between a Spring & Neap Tide The differences in the patterns of tides.

Tide Refers to the cyclical rise and fall of sea water.

What causes the water level to rise and fall? The gravitational pull of 3 bodies interacting: 1. Earth’s Gravitational Pull 2. Moon’s Gravitational Pull 3. Sun’s Gravitational Pull * For daily rhythmic tides, only Earth and Moon need to align.

Spring Tide When all three bodies align, you get the biggest tides of the year. (Spring Tide)

Neap Tide When the Sun and Moon are at right angles with each other, you get the lowest tides of the year. (Neap Tide)

Tidal Period Takes 24 hours and 50 minutes to cycle through 1 tidal period During this time, any given point on the Earth should experience 2 tidal crests and 2 tidal troughs.

Types of Tides 1. Diurnal Tide: One high and one low tide per day (Gulf of Mexico and S.E. Asia)

Types of Tides Semi-Diurnal Tide: Two high and two low tides per day (Atlantic coast of U.S. and Europe)

Types of Tides Mixed Tides: Tides vary in order from Low to Medium High to Medium Low to High.