Questions tagged [tides]

Tides are the periodic fall and rise of sea-level due to gravitational forces of the moon, sun or earth-rotation. When asking questions specifically about tides, use this tag and also include the [ocean], [moon], [sun] or [earth-rotation] tag if appropriate.

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What is the significance of amphidromic points related to tides?

On reading about tide formation and the role of moon's gravitational force, I came across the term amphidromic point. Could someone please elaborate this concept?
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Do flights affect tides?

Can artificial satellite positions affect tides? on Space Exploration.SE asks if artificial satellites can affect tides, because they are a lot closer than our natural satellite, even though they are ...
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Is it possible to know the tides of a particular location 50 years or 100 years from now?

Assuming no change in sea level (for the sake of argument), is it possible to know the high and low tides a half century or more in the future? Is information like this available to the general ...
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Why high tides occur simultaneously on opposite sides of the Earth?

From this question, this picture: As tides are mostly (2/3) due to gravity pull from the moon, I'd expect water is pulled in the direction of the moon, and high tide occurs only on the side ...
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What goes into a tide power prediction for every fifteen minutes over the next twenty five years?

I was watching a segment about tidal power generation on a PBS NewsHour broadcast. I've set the time code at about 11:45 to capture a little background. This bit ...
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Topography and flash flooding

I'm looking for a study or document showing the effect of the topography, slopes, the sea level and the tide on flash flooding occurrence. Thanks in advance
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Global tide calculation

I am familiar with the concept of harmonic tide coefficients and was wondering about the simplest software solution to calculate tides anywhere, worldwide. Are there any available, open source ...
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How was Venice flooded?

If I understand this correctly, Venice was not flooded due to sudden rainfall causing rivers to overflow, but due to the high tides. These high tides were caused by an alignment of sun, which was ...
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How is sea level measured?

In comments on Earth changes due to global climate change, sea level changes is a common topic. I hear quotes about sea level changes in the centimeter and even millimeter range and wonder how such ...
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What proportion of the energy input to the ocean tide system comes from the sun?

The earth's ocean tides are primarily driven by the moon, but also by the sun. The relative strengths of the related tidal constituents varies from place to place across the globe. But what is the ...
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Simple numerical model of tide with an elliptic scheme

I have recently been given the task of developping a coastal model for tides. I have a few requirements, it must not be time stepping in order to be as fast as possible and in finite differences ...
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Can tides at night by consistently higher than in the daytime? [closed]

Can the tides at night be consistently higher than in the daytime in southwest Australia in the port of Fremantle? Also, what is the explanation for the tides being significant during a part of the ...
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Presence of cross stratified conglomerates in fan deltas

Why are cross stratified conglomerates found in deposits of fan deltas? I know that fan deltas are alluvial fans that deposit directly into the sea, hence they are poorly sorted.But could not ...
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High tides at Venice

I read somewhere that the new MOSE system can withstand a maximum rise in water of about 3m. I was wondering if that extreme case will happen on the coast line of Lido di Venezia, there will be a ...
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How come the tide is low when the moon is high in the sky

Happily spending my holidays in the Fiji Islands, I noticed a couple of days ago that when the moon was very high in the sky (my shadow was maybe 0.5-1m long) the tide was low. That really puzzled me....
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What was the storm surge height from Hurricane Harvey?

The numbers bandied about have been 3.6 m (12 feet) and even 4.6 m (15 feet), but something told me that was unlikely. As a guy who could "almost" slam dunk a basketball, the idea of a 3 m (10 feet) ...
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Are ramp pumps the solution to the global water problem? [closed]

For the past few years people have been trying to solve the global water problem (especially in Africa), and what better way than being echo friendly. So my question is, can you use the tidal energy ...
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Is the Earth heated up by the tides?

Reading about moons of other planets they often get heated up by the tides so for example Io and Europe of Jupiter get friction by which eruptions and liquid water can arise. But is there also an ...
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Why do high tides vary month to month?

I've noticed that some ‘highest‘ high tides in one month are bigger than the highest high-tide of previous months. Why is this so?
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Musing on Earth's gravity

(a) What, if anything, is the difference between Earths geographic center, i.e. mid-point of the spin axis, and the gravitational center? (b) What is the average distance between the Earth's center ...
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Why don't spring tides occur at full/new moon (age of tide)?

Tides observations everywhere show that spring tides occur not at full or new moon, at the time of maximum driving forces, but typically a day or two later. What causes this delay?
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How often do king tides (perigean spring tides) occur?

Recently, there has been a lot of information about "King Tides" (i.e, perigean spring tides) on the news with a number of groups relating the peak king tide to future normal conditions (2050) under ...
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How to correct PSMSL data for GIA?

I have a PSMSL RLR (revised local reference) sea level dataset with records from various tide gauges. Can anyone explain how to correct them for GIA (glacial isostatic adjustment) using the ICE-5G ...
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Relationship between tides and earthquakes

Ide et al. (2016) suggest that earthquakes (especially those of high magnitudes) are more probable during periods of high tidal stress (during full and new moons). While they show a comprehensive ...
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What would be the impact on tides if the earth had no tilt?

I would like to know what would be the impacts/effects on the tides if earth were to have no tilt (perpendicular to plane of ecliptic)?
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When specifying phase and amplitude for a tidal constituent, what date/time does phase start from?

It is common to describe tidal elevations at a given location by giving the phases and amplitudes of tidal constituents. One such application is for setting the open boundary conditions for regional ...
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The motion of tides

I found this animation from a satellite: which shows the motion and elevation of tides on a certain date. Can you find an animation of a date when there is a spring tide? my question is as follows: ...
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Definitions of tidal harmonic constituents…?

Does anyone know where there is a detailed definition for tidal harmonic constituents? There is loads of stuff on $M_2$, $S_2$, $N_2$, etc. (all the common ones), but there are a great many more, some ...
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Phase of S2 constituent in tidal prediction

I ran the ETERNA code for the prediction of tidal gravity at some station. Then I use Fourier analysis to recover the amplitude and phase of the S2 constituent. As I understand, the phase of the S2 ...
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How much do tides affect earth's rotational velocity?

Many of us are familiar with an exaggerated picture of the Moon's effect on Earth's tides: Since the Earth is not uniformly covered with water, however, I imagine that the tidal effect will depend on ...
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Modelling sea levels with gravitational parameters

Are there any publicly available programs or source code for modelling global (or local) changes in sea level which include parameters for gravitational tidal effects? I have a physics background, ...
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If the distance between Earth and the moon were changed, would the effects be immediate? [closed]

I need your help on a possible (but perhaps low probability) scenario for how the distance between Earth and the moon could change: say a large object from the Kuiper Belt manages to make its way into ...
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What are the effects of underwater “windmills”?

Most early examples of tidal energy generators used barrages (damns) to generate electricity (La Rance, Kislaya Guba, Annapolis Royal). Meanwhile, a lot of newer projects use rotary blades in the ...
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What is the area with the largest velocity vertical shear in the ocean?

While there are areas with really strong tidal currents in the ocean, these currents tend to be primarily barotropic. My question relates to the largest vertical difference in velocity and it is ...
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How to Calculate the Equilibrum Function for use in Tide Calculations using Harmonic Constituents

I have found a wealth of information using Harmonic Constituents to calculate tide levels. H(t) = Amplitude * cos ( t * harmonicSpeed + phase lag). Yet when I try to apply this to constituents from ...
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What visual wave behaviour help to tell if a tide is going in or out?

I have always wondered how someone could tell, by a brief observation (a few minutes at most), whether a tide is receding or advancing on a rainy day. Assuming there is no access to tide times and ...
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728 views

What tidal databases are available to be used as model boundary conditions?

I am trying to set up a coastal ocean model simulation. I am looking for different ways to force the tidal boundary condition in the model to study how uncertainty in the tidal forcing in the boundary ...
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What influences tide-height the most? Can I guess the height by looking on a globe?

I hope that the question title is resonably clear: What are the most significant factors which influence the tide height? I'm aware of the following couple of them: Sun-Earth-Moon relative position (...
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What can we learn by studying lunar atmospheric tides?

Lunar atmospheric tides are likely insignificant for weather, although Guoqing (2005) asserts that The lunar revolution around the earth strongly influences the atmospheric circulation. They don't ...
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Why is there a daily inequality for low tides?

I understand why there is a daily inequality for high tides. What I do not understand is why the low tides are not equal. The data all seems to be somewhere along the lines of but the theory seems to ...