Tides are a part of the natural phenomenon that our World has recited for ages. It’s as mundane as thunder and lightning. It’s almost in tune with nature that we often fail to notice these unique visitors on the beach shore. They are a reliable phenomenon that adds more allure to the ocean. When the ocean waves rise to the highest point, they form a crest, where high tide occurs. Subsequently, the moment the sea hits the lowest part, it’s called a low tide. There is so much more to know when it comes to tides, like what is the lowest range tide, and do you know there’s half moon tide or minimal tide? Let’s begin and find out.
1. What are the 4 Types of Tides?
The types of tides are Diurnal, Semidiurnal, Mixed Semidiurnal, and Metrological tide.
- The diurnal tide cycle occurs in an area that experiences an alternative of one high tide and one low tide every lunar day. These types of tide cycles are prone to happen in the areas of the Gulf of Mexico.
- The semi-diurnal tide cycle is prevalent in areas that experience two high tides and two low tides. Concerning the size of these tidal waves, they are approximately equal, and they occur every lunar day.
- A mixed Semidiurnal tide cycle is observed in areas that experience two high tides and two low tides or varying sizes (thereby differing from his predecessor) every lunar day.
- Meteorological tides are influenced by the forces of the atmosphere, such as wind, barometric pressures, rainfall, melting ice caps, and dry land. One such instance is a storm which causes the wind and the inverted barometric pressure to play a role in a dramatic increase of sea level. The other tides are listed as astronomical tides since they are influenced by the gravitational pull of the sun, moon, and earth.
2. What is the Average Tidal Range?
The average tidal range is the difference between the maximum and minimum water levels during a tidal cycle. In other words, the tidal range is a quantitative way of determining the area above water at low tide and underwater at high tide. This area is what’s called the intertidal zone. The tidal range has a broader influence on the geographical features of beaches, estuaries, sea shores, and marine life and their way of survival.
The average tidal range varies from place to place drastically. But the tidal range in the open ocean is about 1 meter (3 feet). In comparison, coastal tidal ranges can range from 0 feet to even 52 feet.
3. When the Tidal Range is Maximum and Minimum?
The tidal range is maximum every 14 days during the full moon and the new moon phases. These are otherwise called spring tides.
The tidal range is minimum when they’re halfway between spring tides which occurs during the first and third quarter moon phases. These are otherwise called neap tides, also called minimal tides. (See What is the Difference between Sound and Bay?)
4. What is the Lowest Range Tide?
The tidal range is a factor that changes depending on the position and the alignment of the sun and the moon towards the earth relatively. The lowest range tide occurs when the sun and the moon are out of phase. The lowest tidal range corresponds with the neap tides and during tropic tides when the moon is positioned directly above the equator. The lowest range tide is found in the Mediterranean or the Baltic enclosed seas. They rise about 30 centimeters (about a foot).
5. What is a Minimal Tide?
A neap tide is a phase when the tidal range is supposedly minimal. Therefore, it’s a minimal tide. 2 neap tides occur every month. These tides occur under a particular alignment of two important celestial bodies, the sun, and the moon. When these are aligned at right angles to one another, neap tides occur. The lowest range tides also appear alongside the neap tides.
Another pointer to the occurrence of this lowest range tide is the quarter moon phases and destructive interference. Destructive interference is when two waves set in the opposite direction of the same amplitude interfere with each other in a disruptive manner.
6. What causes Low Tide?
The gravitational pull of the moon is called the tidal force. This gives rise to two bulges on our globe. One bulge is located right under the moon at any given period, called the sublunar point. The other bulge is located contrastingly to the sublunar point and is called the antipodal point. As the earth constantly rotates around its axis, certain regions move away from the bulges while others creep in closer to either of the bulges. The farther the region drifts away from one of the bulges, the lower the tide becomes.
This is what causes a low tide. The lowest range tide is the lowest point of a high tide when the difference between the high and low tide is the least.
7. Why is there no Tide in the Caribbean?
The Caribbean is a body of water that can be grouped with the Caspian Sea, black sea, Baltic Sea, and the Mediterranean for their collective absence of tides. This doesn’t mean a complete lack; they have small tides that aren’t strong enough from a navigation perspective to be considered. The sea in the Caribbean doesn’t rise, doesn’t fall indifferent to the high and low tides that circumference it along the coastlines of the Atlantic. There are regions on the earth’s surface, such as the Caribbean, that are complex in terms of their size and geographical nature, making them non-tidal zones.
These regions possess no continental coastlines where when the water from large oceanic bodies is pushed inwards, they can’t form tides. This is because of the little place left on these shores for the water to wash up against and form a tidal range. Their relatively narrow shorelines make it difficult to maintain a higher average tidal range. Instead, these parts of the ocean have minimal tides of the lowest tidal range. (See How Far below Sea Level is Florida?)
8. Where is there no Tide?
Certain regions on the earth’s surface don’t reciprocate the effect of tidal forces. Therefore, this causes a non-tidal zone that has a minimal tide. Additionally, amphidromic points are places on the ocean surface with little to no tide. This is attributed to the continental masses interfering with the westward movement of the tidal bulges.
The tidal range becomes correspondingly the lowest range tide the closer it is to the amphidromic point. There are said to be one dozen such points distributed all across the ocean. The Pacific alone contributes five such amphidromic points. The Caribbean, the Mediterranean, the Baltic Sea, the Black Sea, Caspian Sea are areas where tides are near absent or zero. These non-tidal zones have non-wavy, still oceans.
9. What is the Biggest Tidal Range?
The biggest tidal range is located in Canada. It’s nested between the provinces of Nova Scotia and Brunswick. Situated in the Bay of Fundy, it holds the record for having the World’s largest tidal range. The average height variation on earth in sea level from tides is three feet. While this is the water level present in Wolfville, Nova Scotia’s Minas Basin can reach a tidal height variation of about 53 feet. This is almost 16 meters higher than that of low tides. Check out How do the Hydrosphere and Biosphere Interact with Each Other?
10. Where are the 5 Highest Tides in the World?
These highest tides are made possible by the sun and moon’s combined gravitational pull. This happens every two weeks. The five highest tides in the World are:
- Burntcoat Head, Bay of Fundy, Nova Scotia – 11.7 meters (38.4 feet).
- Leaf Lake, Ungava Bay, Quebec – 9.7 meters (32.0 feet).
- Port of Avonmouth, Bristol, United Kingdom – 9.6 meters (31.5 feet).
- Sunrise, Turnagain Arm, Cook Inlet, Alaska – 9.2 meters (30.3 feet).
- Rio Gallegos (Reduccion Beacon), Argentina – 8.8 metres (29.0 feet).
11. What is a Half Moon Tide?
A half moon tide usually occurs after a spring tide. A unique phenomenon occurs after a seven-day duration following a spring tide where the sun and moon are at right angles to each other. This causes the oceanic bulge, attributed to the sun, to be partially canceled out by the bulge caused by the moon. As a result, it births a tidal range where the high tides become slightly lower, and the low tides become marginally higher than their average height. These are called neap tides. Since these occur during the first and third quarter moon, when the moon has a half-full appearance, these are known as a half-moon tide.
Here comes the end of this tidal journey. Note that the rhythmic rise and fall of tides orchestrated by the gravitational pull of the sun and the moon have long been studied by oceanographers. Even the ocean lives are influenced and adapted to give rise to curious survival skills. Hope you enjoyed reading all the information related to the unique persona of lowest range tide, average range, and high tides. (Also read What Transports Most of the Sediment in Beach Environments?)