Tides are caused by the gravitational attraction of the sun and moon upon the eath's oceans, combined with the daily rotation of the earth. The motion of the sun. moon, and earth are entirely predictable, and so we can predict tides well into the future. Unfortunately, a large number of factors make the prediction process quite complex. As we demand more and more accuracy in the times and heights our predictions, so does the process become more complex.

There are basically three types of tidal regime. Diurnal tides are those where one High and one Low Water occur during a period of 24 hours - mainly experienced in the Pacific Ocean. Semi-Diurnal tides are characterised by having two High and Low Waters in a 24 hour period - mainly experienced in the Atlantic Ocean. See similar questions...

In the main a spring tide occurs 2 days after the date of New and Full Moon. However, a Spring Tide can occur anywhere from 0 to 4 days after New and Full Moon - it just depends upon the geographical location of the tidal station concerned and how the tide-generating forces are affected by friction on the surface of the earth. See similar questions...

The reason is that when the New and Full Moon occur, the two major semi-diurnal constituents (M2 and S2) of the tide raising force are precisely in phase. Consequently, High Water Springs will always occur at about the same time of day. To say that the Spring High Water (after New and Full Moon) should occur at local midday/midnight is purely theoretical, even though, coincidentally, this may be the case at your local port. See similar questions...

PAP is a condition in which surfactant, a normal milky substance lining the lungs, accumulates to abnormally high levels and results in a feeling of breathlessness. There are several different clinical forms or types of PAP; primary (also called idiopathic or occasionally acquired), secondary and congenital forms. Primary PAP is associated with high levels of antibodies that recognize and neutralize an essential blood protein called GM-CSF (granulocyte-macrophage colony-stimulating factor). See similar questions...

Fistula (VVF and/or RVF) results from prolonged, obstructed labor. It occurs when a woman is unable to deliver her baby safely and cannot access emergency obstetric care, including a cesarean section. The constant pressure of the baby's head causes the tissues to disintegrate between the vagina and the bladder and/or between the vagina and the rectum. Top See similar questions...

This is a very difficult question to answer. Some researchers say that if the occlusion (bite) of someone is not correct they will brux. Others say that it is a central nervous system disorder. Others say it is a multifaceted problem. For all practical purposes......EVERYONE bruxes. Therefore, the question is NOT whether a person does in fact brux. Rather, the better question is to what degree do they brux. See similar questions...

Varicose veins are most commonly found on the legs of women and men who spend a lot of time on their feet. Birth control pills, hormone therapy, obesity, weight fluctuation, and constipation can also add to the development of varicose veins. See similar questions...

The tides can give you much grief if you don't pay attention or have an equipment breakdown. This can result in the "walk of shame", a long walk carrying your gear back to the launch or a rescue. Normally the best sailing is during an ebb tide, where the water is flowing out of the Bay. Here the current is in the opposite direction of the wind. This increases the apparent wind, makes it easy to stay upwind and can cause big swells. See similar questions...

Below is a listing of 50 locations from around the world where the largest range of tides that have been observed. Station Mean Range (feet) Burntcoat Head, Minas Basin, Bay of Fundy, Nova Scotia 38.4 Horton Bluff, Avon River, Minas Basin, Bay of Fundy, Nova Scotia 38.1 Amherst Point, Cumberland Basin, Bay of Fundy, Nova Scotia 35.6 Parrsboro (Partridge Island), Minas Basin, Bay of Fundy, Nova Scotia 34.4 Hopewell Cape, Petitcodiac River, Bay of Fundy, New Brunswick 33. See similar questions...

A thorough source of information about the history, science, and observation of all types of eclipses is located at: http://www.earthview.com/tutorial/causes.htm. See similar questions...

The range between consecutive High and Low waters at a port changes over a full lunar month. When this range is at its greatest the tides are referred to as 'Spring tides' and when the range is at its smallest the tides are 'Neap tides'. See similar questions...

The water levels of the Great Lakes have long-term, annual, and short-term variations. Long-term variations depend on the precipitation and water storage over many years. Annual variations occur with the changing seasons. There is an annual high in the late spring and low in the winter. These changes occur at a rate that can be measured in feet per month. See similar questions...

Within the "Water Level Observations" section of our website you will find a heading labeled Accepted Datums. In this area you will be able to obtain datum values for water level stations. The two commonly used tidal ranges are listed for each station. These ranges are the Mean Tidal Range (MN) and the Diurnal Tidal Range (GT). See similar questions...

The tides wash you up and down the channel, so inevitably you will end up swimming further than just 34 kilometres. What causes problems is if you mis-time your crossing, and the tides move you up and down the coast, making you swim further. It could also turn as you approach the beach, pushing you back out and making you swim further. Also, the land falls away sharply on either side of Cap Gris Nez, so the distance to land increases drastically if your pilot misjudges your approach. See similar questions...

Tides are generated by the rotation of the earth within the gravitation fields of the moon and sun. Tides change each day in two main patterns: A half-day cycle: due to the rotation of the earth within the gravitational field of the moon, resulting in a period of 12 hours 25 minutes between successive high tides A 14-day cycle: resulting from alignment of the gravitational fields of the moon and sun. See similar questions...

Absolutely. You can check current or future tides and the weather by going to either our Tides Page or our Weather Page. See similar questions...

First the behaviour of the tide has to be recorded by a tide gauge at each particular location and the results subsequently analysed. The results of the analysis, known as tidal constants, are then used in a computer program to predict the behaviour of the tide for any period required. A more detailed explanation is available at TotalTide. Upon exiting the TotalTide demonstrator, clicking on 'About Tidal Prediction' will bring up pages about tides and tidal theory. See similar questions...