Spring Tide vs. Neap Tide

A neap tide occurs only twice a month, during the first and third quarter moon. A neap tide has the lowest high tides and highest low tides of the month. The tidal range (distance on the beach between high and low tide) is at its lowest.

A spring tide also occurs twice a month, but at the full and new moon. A spring tide has the largest tidal range of the month, so the distance between high and low tide is the greatest. This means higher high tides and lower low tides.

The pattern of the lunar month's spring and neap tides is nicely animated at this site: http://oceanservice.noaa.gov/education/kits/tides/media/supp_tide06a.html

Tides?? Here are some helpful resources.

The Moon's gravitational pull on Earth causes tides! What is a tide? Check out the videos at these links:

http://videos.howstuffworks.com/hsw/10000-the-moon-tides-video.htm

This page also includes many different videos about the moon that answer some interesting questions such as 'How did the Moon form?'

The second video is from NASA:
http://www.nasaimages.org/luna/servlet/detail/NVA2~15~15~53648~124808:What-is-a-Tide

The animation at the link below illustrates how high and low tides work. There are about two high tides and two low tides every day.
http://science.nasa.gov/headlines/images/missingtides/dissipation.gif