Topic summary
Neap tide
Extracted from the Wikipedia article Tide.
Range variation: springs and neaps
When the Moon is at first quarter or third quarter, the Sun and Moon are separated by 90° when viewed from the Earth (in quadrature), and the solar tidal force partially cancels the Moon's tidal force. At these points in the lunar cycle, the tide's range is at its minimum; this is called the neap tide, or neaps. "Neap" is an Anglo-Saxon word meaning "without the power". Neap tides are sometimes referred to as quadrature tides.