Tides and the Kermadec Trench
A Purple Rock Crab
By: Josh Breland
The tidal patterns around New Zealand are very different than what we are used to in the northern hemisphere. Along the New Zealand coast, tidal patterns are semi-diurnal. This means that almost every day two high tides and two low tides will occur. The maximum tidal ranges of New Zealand are tides exceeding 3.5 meters in some regions, and the lowest tides are 2 meters or less in some regions. The Moon is the main force behind New Zealand's semi-diurnal tides, which causes tide cycles that last on average 12 hours and 25 minutes. There is an area in New Zealand called Cook Straight where between the North and South Islands, the tide travelling north along the east coast pass the southbound tide to the west. The strong difference between these tides, along with the east/west tide height difference, produces a pattern of strong currents that flow through Cook Strait.
The tidal patterns around New Zealand are very different than what we are used to in the northern hemisphere. Along the New Zealand coast, tidal patterns are semi-diurnal. This means that almost every day two high tides and two low tides will occur. The maximum tidal ranges of New Zealand are tides exceeding 3.5 meters in some regions, and the lowest tides are 2 meters or less in some regions. The Moon is the main force behind New Zealand's semi-diurnal tides, which causes tide cycles that last on average 12 hours and 25 minutes. There is an area in New Zealand called Cook Straight where between the North and South Islands, the tide travelling north along the east coast pass the southbound tide to the west. The strong difference between these tides, along with the east/west tide height difference, produces a pattern of strong currents that flow through Cook Strait.