| A | B |
|---|
| are very long-period waves that move through the oceans in response to the forces exerted by the moon and sun | tides |
| When the highest part, or crest of the wave reaches a particular location, ____________ occurs. | high tide |
| corresponds to the lowest part of the long period wave, or its trough | low tide |
| The difference in height between the high tide and the low tide is called the __________ | tidal range |
| A horizontal movement of water often accompanies the rising and falling of the tide and is called the | tidal current |
| The incoming tide along the coast and into the bays and estuaries is called a _______ | flood current |
| The outgoing tide is called an _______. | ebb current |
| The weakest currents occur between the flood and ebb currents and are called | slack tides |
| In the open ocean tidal currents are relatively ________. | weak |
| Ocean tides result from the gravitational attraction of the ___ and ____ on the oceans of the earth | sun moon, moon sun |
| states that the gravitational attraction between two bodies is directly proportional to their masses, and inversely proportional to the square of the distance between the bodies | Newton's law of universal gravitation |
| Two tidal bulges are created on opposite sides of the Earth due to the moon's gravitational force and ____________ counterbalance. | inertia's |
| As the moon revolves around the Earth, its angle increases and decreases in relation to the equator. This is called | declination |
| Unlike a solar day, however, a __________ is 24 hours and 50 minutes | lunar day |
| High high tides, and very low, low tides are called | spring tides |
| Moderate tides are called ________ | neap tides |
| When the moon is farthest from the Earth (at ______), the lunar tide-raising force is smaller, and the tidal ranges are less than average | apogee |
| Time when earth is closest to sun | perihelion |
| When the two highs and the two lows are about the same height, the pattern is called a | semi-daily, semi diurnal |
| When the Earth is furthest from the sun | aphelion |
| If the high and low tides differ in height, the pattern is called a mixed | mixed semi diurnal |
| If an area has only one high and one low tide each day, it is called a ________ | diurnal tide |
| In the past, most water level measuring systems used a recorder driven by a float in a | stilling well |
| Timing and recording on tidal measurement intrutments is controlled on the new stations by a | goes, Geostationary Operational Environmental Satellite |
| Once a month, when the moon is closest to the Earth (at _________), tide-generating forces are higher than usual, producing above-average ranges in the tides | perigee |
