The Moon's Effect on Tides
The How and Why of Oceanic Tides I have always been fascinated with the tides of Earth’s oceans. Being from the coastal state of Massachusetts, I consider the beach my summer home. As someone who has spent so much time near the ocean, I’ve grown up knowing tide schedules, when the best times to surf are, and other tidal trivia alike, but up until now, I had no idea what caused the tide levels to change.
In my research, I’ve discovered that high and low tides are mainly caused by the gravitational pulls of the sun and moon on the water in Earth’s oceans. Types of tides are classified by the position of the sun and moon. These tides are called spring tides and neap tides, and can be more extreme due to the perigee and apogee of the moon. Tides also follow a schedule which is directly related to Earth’s regular rotation, and the moon’s regular orbit (McConnell, et al).
Spring tides occur when the gravity of the moon is combined with the gravity of the sun, and neap tides occur when the gravitational pull of the sun and moon act against each other. Spring tides are seen at the full moon and new moon, and neap tides are seen at the quarter moons. The immense amount of gravity at a spring tide causes the high tides to be very high, and the low tides to be very low. Spring tides take waters to an extreme, whereas neap tides moderate water levels. Water levels are moderated at a neap tide because the gravitational pulls of the sun and moon cancel each other out, which flattens the bugles of the water. The water level is higher by 20 percent in high tides and lower by 20 percent in low tides as a result of spring and neap tides (Cooley).
The terms perigee and apogee refer to the moon’s proximity to Earth. Perigee and apogee affect the spring and neap tides of the Earth’s oceans as they differentiate the gravitational pull of the moon. Perigee is when the moon is closest to Earth, and since gravity has a greater effect on an object when it is in closer proximity to
In my research, I’ve discovered that high and low tides are mainly caused by the gravitational pulls of the sun and moon on the water in Earth’s oceans. Types of tides are classified by the position of the sun and moon. These tides are called spring tides and neap tides, and can be more extreme due to the perigee and apogee of the moon. Tides also follow a schedule which is directly related to Earth’s regular rotation, and the moon’s regular orbit (McConnell, et al).
Spring tides occur when the gravity of the moon is combined with the gravity of the sun, and neap tides occur when the gravitational pull of the sun and moon act against each other. Spring tides are seen at the full moon and new moon, and neap tides are seen at the quarter moons. The immense amount of gravity at a spring tide causes the high tides to be very high, and the low tides to be very low. Spring tides take waters to an extreme, whereas neap tides moderate water levels. Water levels are moderated at a neap tide because the gravitational pulls of the sun and moon cancel each other out, which flattens the bugles of the water. The water level is higher by 20 percent in high tides and lower by 20 percent in low tides as a result of spring and neap tides (Cooley).
The terms perigee and apogee refer to the moon’s proximity to Earth. Perigee and apogee affect the spring and neap tides of the Earth’s oceans as they differentiate the gravitational pull of the moon. Perigee is when the moon is closest to Earth, and since gravity has a greater effect on an object when it is in closer proximity to
Cited: "Apogee and Perigee of the Moon." MoonConnection. MoonConnection, n.d. Web. 10 Dec 2012. <http://www.moonconnection.com/apogee_perigee.phtml>. Cooley, Keith. "Keith 's Moon Page." Moon Tides. N.p., 2002. Web. 10 Dec 2012. <http://home.hiwaay.net/~krcool/Astro/moon/moontides/>. McConnell, David, David Steer, Catharine Knight, and Katharine Owents. The Good Earth. 2nd ed. New York: McGraw-Hill, 2010. 362-364. Print. "Tides." OceanLink. OceanLink, n.d. Web. 11 Dec 2012. <http://oceanlink.island.net/oinfo/tides/tides.html>. ceans. in Earth 'ater. caused tides are mainly caused water to schedules, when the best surf is, and other tidal trivi