The regular rise and fall of sea level caused by gravitational forces of the Moon and Sun is called?

The regular rise and fall of sea level caused by gravitational forces of the Moon and Sun is called?

• A. Tides
• B. Waves
• C. Currents
• D. Hurricanes

Answer: (A)

Tides—the regular rise and fall of sea level caused by gravity from the Moon and the Sun. The Moon’s gravity pulls on Earth’s oceans, creating a bulge on the side closest to the Moon and another on the far side. As Earth rotates, coastal areas move into and out of these bulges, producing high tides when a bulge is overhead and low tides when it isn’t. The Sun also exerts gravity, adding to or subtracting from the Moon’s effect; its influence is weaker because it’s much farther away but still modulates the pattern. When the Sun, Moon, and Earth align during full or new Moon phases, their gravities combine to produce higher high tides and lower low tides—spring tides. When the Sun and Moon are at right angles, their pulls partially cancel, giving lower high tides and higher low tides—neap tides. The exact heights and timings vary with coastline shape and ocean depth, so some places experience two highs and two lows each day. Waves are wind-driven surface disturbances, currents are horizontal movements of water, and hurricanes are large tropical storms; none describe the regular gravitational rise and fall of sea level that defines tides.

Tides—the regular rise and fall of sea level caused by gravity from the Moon and the Sun. The Moon’s gravity pulls on Earth’s oceans, creating a bulge on the side closest to the Moon and another on the far side. As Earth rotates, coastal areas move into and out of these bulges, producing high tides when a bulge is overhead and low tides when it isn’t. The Sun also exerts gravity, adding to or subtracting from the Moon’s effect; its influence is weaker because it’s much farther away but still modulates the pattern. When the Sun, Moon, and Earth align during full or new Moon phases, their gravities combine to produce higher high tides and lower low tides—spring tides. When the Sun and Moon are at right angles, their pulls partially cancel, giving lower high tides and higher low tides—neap tides. The exact heights and timings vary with coastline shape and ocean depth, so some places experience two highs and two lows each day. Waves are wind-driven surface disturbances, currents are horizontal movements of water, and hurricanes are large tropical storms; none describe the regular gravitational rise and fall of sea level that defines tides.