What is the difference between low tide and high tide?

Question

When do each take place and are the times different for different countries???

any websites

Answer 1

It's quite a complicated thing to explain in details so I'll stick to the basics.

The moon is the greatest influence on tides, it's gravity pulls at the seas and oceans. The Sun does likewise but it's gravitational pull is weaker. The moon orbits around the earth and the earth and moon orbit together around the sun, the Earth also rotates.

This pattern of movement means that the forces affecting tides are sometimes pulling together (e.g. alignment = Earth, moon, Sun so the moon and sun are pulling in the same direction) at other times they're pulling against each other (Sun, Earth, moon - the Earth in the middle with the Sun and moon pulling in opposite directions).

Because the Earth is rotating the gravitational pull of the sun and moon is constantly pulling at different parts of the seas and oceans, it's almost as if they're trying to suck the water off the planet.

It's this constant gravitational battle that sometimes pulls the sea out (low tide) and sometimes pulls it in (high tide). When the Sun, moon and Earth are in allignment is when the highest high and lowest low tides occur (called springs and neaps).

The geography of the coastline also has a role to play and in some places this can cause strange effects. For example, at Poole in England the tide starts to go out, changes course and begins to come back in, then goes out fully.

High and low tides occur simultaneously at different locations around the planet and if you were to look down from space on a coastline somwehere you'd see the high and low tides moving up (or down) the coastline - it's not the case that the tide retreats and advances from all parts of the coastline at the same time.

There's a little over 12 hours between successive high and low tides so they occur progressively later from one day to the next. Tide times can be found on several websites and are sometimes included in the local media.

Answer 2

High and low tides are caused by the position of the Sun and Moon as the Earth follows its annual orbit. There are charts available to tell you when the tide will be at various stages each day and how high they will be above mean water level. These are often printed in newspapers in the weather section, for example, or in the Old Farmers' Almanac. The time are not only different for each country and continent, but they can also be different for areas along the ocean as little as a mile apart from each other.

Answer 3

Look up tide tables. Times of high and low tides change every day.

Answer 4

A tide is a repeated cycle of sea level changes in the following stages:

Over several hours the water rises or advances up a beach in the flood tide.
The water reaches its highest level and stops at high tide. Because tidal currents cease this is also called slack water or slack tide. The tide reverses direction and is said to be turning.
The sea level recedes or falls over several hours during the ebb tide.
The level stops falling at low tide. This point is also described as slack or turning.
Tides may be semidiurnal (two high tides and two low tides each day), or diurnal (one tidal cycle per day). In most locations, tides are semidiurnal, but because of the diurnal contribution, there is a difference in height (the daily inequality) between the two high tides on a given day; these are differentiated as the higher high water and the lower high water in tide tables. Similarly, the two low tides each day are referred to as the higher low water and the lower low water. The daily inequality changes with time and is generally small when the Moon is over the equator.[2] The various frequencies of astronomical forcing which contribute to tidal variations are called constituents. In most locations, the largest is the "principal lunar semidiurnal" constituent, also known as the M2 (or M2) tidal constituent. Its period is about 12 hours and 24 minutes, exactly half a tidal lunar day, the average time separating one lunar zenith from the next, and thus the time required for the Earth to rotate once relative to the Moon. This is the constituent tracked by simple tide clocks.[3]

Tides vary on timescales ranging from hours to years, so to make accurate records tide gauges measure the water level over time at fixed stations which are screened from variations caused by waves shorter than minutes in period. This data is compared to the reference (or datum) level usually called mean sea level.[4]

Constituents other than M2 arise from factors such as the gravitational influence of the Sun, the tilt of the Earth's rotation axis, the inclination of the lunar orbit and the ellipticity of the orbits of the Moon about the Earth and the Earth about the Sun. Variations with periods of less than half a day are called harmonic constituents. Long period constituents have periods of days, months, or years.


[edit] Tidal range variation: springs and neaps

An artist's conception of spring tide
An artist's conception of neap tideThe semidiurnal tidal range (the difference in height between high and low tides over about a half day) varies in a two-week or fortnightly cycle. Around new and full moon when the Sun, Moon and Earth form a line (a condition known as syzygy), the tidal forces due to the Sun reinforce those of the Moon. The tide's range is then maximum: this is called the spring tide, or just springs and is derived not from the season of spring but rather from the verb meaning "to jump" or "to leap up". When the Moon is at first quarter or third quarter, the Sun and Moon are separated by 90° when viewed from the earth, and the forces due to the Sun partially cancel those of the Moon. At these points in the lunar cycle, the tide's range is minimum: this is called the neap tide, or neaps. Spring tides result in high waters that are higher than average, low waters that are lower than average, slack water time that is shorter than average and stronger tidal currents than average. Neaps result in less extreme tidal conditions. There is about a seven day interval between springs and neaps.

The changing distance of the Moon from the Earth also affects tide heights. When the Moon is at perigee the range is increased and when it is at apogee the range is reduced. Every 7½ lunations, perigee and (alternately) either a new or full moon coincide causing perigean tides with largest the tidal range, and if a storm happens to be moving onshore at this time, the consequences (in the form of property damage, etc.) can be especially severe.

Answer 5

all i know is the moon controls the tides!

Answer 6

From a few inchs to many feet.

Answer 7

google it.