An Introduction to Tides

The periodic rise and fall of sea level, known as the tide, is caused by the gravitational interactions of the Moon and Sun on the oceans of the Earth. While gravity provides the driving force, the rotation of the Earth, the size and shape of the ocean basins and local coastal circumstances ultimately determine the magnitude and frequency of the tide at a particular place.

The following links provide a basic understanding of tidal theory and a description of tidal phenomena pertaining to New Zealand.

• The Cause and Nature of Tides
• Tides Around New Zealand
• Analysis and Prediction
• Meteorological Effects
• Making Sea Level Measurements