WhenToVisit

· ** What are Tides? **  o Tides are changing levels in how deep the water is in the ocean along the seashore. These different levels are caused by the forces of gravity from the // moon //and // sun // on the// Earth //. You see, the moon, sun, and Earth are like giant magnets that push and pull on one another. This causes little changes in the ocean throughout each day and causes low tide and high tide.

o The // intertidal zone // is the areas of the seashore that can be exposed between high & low tide; this is where tide pools can be found.


 * *Objective **: When asked, the learner will be able to list all three objects that work through gravity to cause high and low tides in the ocean. (In the iPhone app, we will present a graphic that shows the intertidal zone.)
 * *Objective **: When shown a graphic of the coastal environment, the learner will select (point to) the intertidal zone, as defined in the iPhone app.

· ** When to Visit Tide Pool? **  o You should make plans to visit tide pools when they are visible at // low tide // each day during daylight hours. This is when the water levels are lower along the coast and when tide pools are created & visible to visitors. You should visit Sammy and his friends at their tide pool homes during the daylight hours because that is safest for you to walk around in the slippery environment.

** · ****How Do You Read a Tide Chart?**

o The best time to visit tide pools are at low tide and during daylight hours, which typically happens only once a day. The // winter //months are often best, as low tides occur most frequently during daytime hours when the moon is full or new. This causes spring tides, when the sun, moon, and Earth all are lined up equally (we can show a graphic of this in the iPhone app material). These produce higher high tides and lower low tides, causing a greater intertidal range (and more visibility for tide pools during the low tide times!)


 * *Objective **: When asked, the learner will name which the correct tidal period for when to visit and view the tide pools.
 * *Objective **: When asked, the learner will state the one season of the year that produces the most low tide periods during daylight hours.
 * *Objective **: Given moveable graphics of the sun, moon, and Earth, the learner will select and move each object into the correct position to depict the cause of spring tides, as defined in the iPhone app material.
 * *Objective **: Given an electronic tide chart on the iPhone app, the learner will be able to state what time of day is best to visit a San Diego tide pool, such that the time chosen is during low tide and during daylight hours.

Sources: 1) Sea World on Tide Pools: []  2) San Diego Coast Life Visitor’s Guide [] 3) National Park Service on Tide Pools: []  4) National Park Service (NPS) - Status and Trends of Ecological Health and Human Use of the Cabrillo National Monument Rocky Intertidal Zone (1990-2005) [] 5) Possible Photos to Use (if allowed to cite) for the iPhone instruction: · Tidal Causes: Gravitational Pull Image []   · Intertidal Zone Graphic  http://ellermanscience1.wikispaces.com/