Transcript Lunar Cycles & Tides - science

Tides
Definition
• The tide is the regular rising and falling
of the ocean's surface.
Cause
• Competing gravitational pull of the Moon
and Sun on different regions of the
Earth.
Moon Tides
• The gravitational pull of the moon
causes the oceans to bulge out in the
direction of the moon. Gravity is pulling
the water away from the Earth and
toward the moon.
Moon Tides
•
Another bulge occurs on the opposite
side of the Earth, because the Earth
is rotating. Inertia causes the bulge
on the other side on the Earth.
http://oceanlink.island.net/oinfo/tides/tides.html
Sun Tides
• Because the Sun is so far away, it does
not have much effect on tides by itself.
– Increases the effect of the moon
– Weakens the effect of the moon
Spring Tide
• When the moon is between the sun and
the earth (at new moon), the sun’s
gravitational pull is in the same
direction as the moon’s. The two
gravitational forces work together to
make extra high high tides and extra
low low tides.
http://oceanlink.island.net/oinfo/tides/tides.html
Spring Tide
• When the moon is on the direct
opposite side of the sun (full moon). The
two gravitational forces work together
to make extra high high tides and extra
low low tides.
Neap Tide
• When the moon is in its first quarter or
its last quarter, the Sun’s gravitational
pull is in perpendicular direction to that
of the moon.
• The sun pulls water away from the areas
of high tide to the areas of low tides,
resulting in lower high tides and higher
low tides.
http://oceanlink.island.net/oinfo/tides/tides.html
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