In honor of World Oceans Day we are using our Nature Note to cover ocean tides, which turns out to be a very interesting topic here in Tetiaroa.
The waves that create tides in the Earth’s ocean basins are influenced by the sun, the moon, and the ocean topography of a region. In French Polynesia, this unique combination of influences essentially cancels the effect of the moon on our tides, so that the influence of the sun on the tides becomes noticeable. The solar tide has a very low amplitude (total range is about 70 centimeters, or 28 inches) and it follows the sun, so it is high at noon and midnight and low at 6am and 6pm.
The tidal situation on Tetiaroa is also affected by the fact that it is an atoll without a large break (pass) in the barrier reef. Constant wave impact on the barrier reef keeps the living coral and algae that maintain it covered in water to a level slightly above mean sea level
Because the tidal situation on Tetiaroa is so unique, observations of the level of the lagoon, the height that mini-waves wash up on a beach, and the ever-changing currents that carry food and sediment, is a constant source of amusement and wonder.