the rise and fall of water levels, or tide, is caused by what?
344029
The moon's got gravity too, and like the Earth pulls the moon, the moon pulls on the Earth's waters. Depending on where the moon is, you get different tides. Kinda like if you move a magnet in a circle around a paperclip. The paperclip will move in different directions depending on where the magnet is.
1061407
Hi Izwan, I'm sure you know that the word "tide" refers to the periodic variation in the surface level of the oceans (and of bays, gulfs, inlets, and estuaries), caused by gravitational attraction of the moon and sun.\n\nThe maximum water level is called "high tide" or "high water" and the minimum level is "low tide" or "low water".\n\nThe time between high tide and low tide, when the water level is falling, is called the "ebb". The time between low tide and high tide, when the tide is rising, is called "flow" or "flood". \n\nThe phrase "as the tide was in" refers to the 'flow' or 'flood'\n\nA sample sentence: The ships entered the harbour as the tide was in.\n\nThe word "tide" could also be used to mean "a favorable occasion; an opportunity."\n\nA sample sentence: Sensing the tide was in his favour, the employee asked his boss for a raise, which he got.
178742
Good question!\n\nIn fact, causing the tide on Earth actually results in the Earth-Moon system losing a little energy during every orbit.  \n\nThis results in the moon moving a little further from the earth to maintain the angular momentum of the system.
1112450
A red tide is when orginisams get into the ocean that affects the sea food.  Such as clams, oysters and the like.  It can and has killed people that have eaten the food affected by the red tide.
730462
It's due to gravity. \nThe Moon Tide\nThe earth and the moon are two great masses that have a significant gravitational pull on each other. This is what keeps the moon in orbit around the earth, and it is also what causes tides to occur in the ocean. Picture the earth with a uniform level of water all around it.  The moon’s gravity pulls on the earth, and pulls the water towards it. The water moves up into a slight bulge on the side of the earth that faces the moon. At the same time, there is a force pulling water out in the opposite direction of the moon.\n\nCheck this link.\n\n\nIt will answer all your questions.\n http://oceanlink.island.net/oinfo/tides/tides.html
1011103
Tides are created because the Earth and the moon are attracted to each other, just like magnets are attracted to each other. The moon tries to pull at anything on the Earth to bring it closer. But, the Earth is able to hold onto everything except the water. Since the water is always moving, the Earth cannot hold onto it, and the moon is able to pull at it. Each day, there are two high tides and two low tides. The ocean is constantly moving from high tide to low tide, and then back to high tide. There is about 12 hours and 25 minutes between the two high tides.\n\nSpring Tides\nWhen the moon is full or new, the gravitational pull of the moon and sun are combined. At these times, the high tides are very high and the low tides are very low. This is known as a spring high tide. Spring tides are especially strong tides (they do not have anything to do with the season Spring). They occur when the Earth, the Sun, and the Moon are in a line. The gravitational forces of the Moon and the Sun both contribute to the tides. Spring tides occur during the full moon and the new moon.\n\nNeap Tides\nDuring the moon's quarter phases the sun and moon work at right angles, causing the bulges to cancel each other. The result is a smaller difference between high and low tides and is known as a neap tide. Neap tides are especially weak tides. They occur when the gravitational forces of the Moon and the Sun are perpendicular to one another (with respect to the Earth). Neap tides occur during quarter moons. \n\nIf we had a second moon our tide system would be more complicated.
540657
The desity of water makes it more suseptable to the pull of the moon's gravitation. Depening on it's course around the earth throughout the year the tides follow in it's wake. Not just hight tide and low tide are effected byt this but swells and tsunamis. The tides are also effected by plate techtonics but science has yet to decide whether the causation is more that plate tectonics are effected by the same gravitational pull as the ocean tides or my subterrainian thermo tides.
123225
electricity or power obtained from moving water\nmainly from dams and tide power plants
496170
The moon, being much nearer to the earth than the sun, is the principal cause of tides. Because the force of gravity decreases with distance, the moon exerts a stronger gravitational pull on the side of the earth that is closer to it and a weaker pull on the side farther from it. The earth does not respond to this variation in strength because the planet is rigid—instead, it moves in response to the average of the moon’s gravitational attraction. The world’s oceans, however, are liquid and can flow in response to the variation in the moon’s pull. On the side of the earth facing the moon, the moon’s stronger pull makes water flow toward it, causing a dome of water to rise on the earth’s surface directly below the moon. On the side of the earth facing away from the moon, the moon’s pull on the oceans is weakest. The water’s inertia, or its tendency to keep traveling in the same direction, makes it want to fly off the earth instead of rotate with the planet. The moon’s weaker pull does not compensate as much for the water’s inertia on the far side, so another dome of water rises on this side of the earth. The dome of water directly beneath the moon is called direct tide, and the dome of water on the opposite side of the earth is called opposite tide.\n\nAs the earth rotates throughout the day, the domes of water remain aligned with the moon and travel around the globe. When a dome of water passes a place on the earth, that place experiences a rise in the level of the ocean water, known as high tide or high water. Between successive high tides the water level drops. The lowest water level reached between successive high tides is known as low tide or low water. Low and high tides alternate in a continuous cycle. The variations that naturally occur in the level between successive high tide and low tide are referred to as the range of tide. At most shores throughout the world, two high tides and two low tides occur every lunar day, the average length of a lunar day being 24 hours, 50 minutes, and 28 seconds. One of these high tides is caused by the direct-tide dome and the other by the opposite-tide dome. Two successive high tides or low tides are generally of about the same height. At various places outside the Atlantic Ocean, however, these heights vary considerably; this phenomenon, which is known as diurnal inequality, is not completely understood at the present time.\n\n© 1993-2003 Microsoft Corporation. All rights reserved.
38650
The sun causes the water to evaporate leaving the salt behind.
232690
There are no effects on human life, other than to get us all talking about eclipses for a brief period. A solar eclipse per se does not effect the tides or cause tidal waves. Tides rise and fall due to the combined effect of the moon and the sun and some rivers can experience tidal bores at certain times, usually rising and falling in intensity with each new moon or full moon. A solar eclipse is just a rare case where a new moon is aligned with the sun and the earth so that it "blots out" the sun in certain places on the Earth's surface.
271740
its called high tide and low tide it has to do with the gravitational pull on large bodies of water.
522768
Flood : When it rains or snows, some of the water is retained by the soil, some is absorbed by vegetation, some evaporates, and the remainder, which reaches stream channels, is called runoff. Floods occur when soil and vegetation cannot absorb all the water; water then runs off the land in quantities that cannot be carried in stream channels or retained in natural ponds and constructed reservoirs (see Dam). About 30 percent of all precipitation is runoff, and this amount may be increased by melting snow masses. Periodic floods occur naturally on many rivers, forming an area known as the flood plain. These river floods often result from heavy rain, sometimes combined with melting snow, which causes the rivers to overflow their banks; a flood that rises and falls rapidly with little or no advance warning is called a flash flood. Flash floods usually result from intense rainfall over a relatively small area. Coastal areas are occasionally flooded by unusually high tides induced by severe winds over ocean surfaces, or by tsunamis caused by undersea earthquakes.\nDrought : Drought, condition of abnormally dry weather within a geographic region where some rain might usually be expected. A drought is thus quite different from aridity, which designates a region that is normally, or at least seasonally, dry.
176407
The tides are mainly influenced by the psition of the sun and moon relative to the earth and their gravitational pull, however the tides are also affected by the flow of water around geographical features it is such a complex system that tides are predicted by past measurement rather than a predicting formulae.
762290
Water...\n\n* Liquid water, eg in rivers and coasts (in the sea this is largely caused by the gravitational effect of the moon);\n* Liquid water is a major cause of landslides - soil becomes over-saturated and therefore loses its adhesion to the soil or rock beneath;\n* The action of freeze-thaw where liquid water seeps into cracks, expands when it freezes thereby widening the crack and ultimately splitting rocks apart;\n* Frozen water in the form of glaciers grinding away at mountains;\n\nOther causes of erosion include:-\n* the wind, especially when it blows sand particles with it which erode rocks;\n* the Sun which alternatively heats and cools rocks so that they split in much they same way as freeze-thaw (especially in desert areas);\n* humans - we contribute to many of the above processes by our own actions, eg deforestation prevents the soil from holding as much water so landslides become more likely; over-farming creates deserts which are subject to wind and sun; coastal "management" often results in more rapid erosion of some areas of coastline
64599
The maximum water level is called "high tide" or "high water" and the minimum level is "low tide" or "low water". High water occurs as two bulges in the height of the oceans; one bulge faces the moon and the other, on the opposite side of the earth, faces away from the moon. For an explanation see below under Tidal physics. There are two low waters positioned at about 90° of longitude from the high waters. At any given point on the ocean, there are normally two high tides and two low tides each day. The common names of the two high tides are the "high high" tide and the "low high" tide; the two low tides are called the "high low" tide and the "low low" tide. On average, high tides occur 12 hours 24 minutes apart. The 12 hours is due to the Earth's rotation, and the 24 minutes to the Moon's orbit. The 12 hours is half of a solar day and the 24 minutes is half of a lunar extension, which is 1/ (29-day lunar cycle). The lunar cycle is what is tracked by tide clocks.\n\nThe time between high tide and low tide, when the water level is falling, is called the "ebb". The time between low tide and high tide, when the tide is rising, is called "flow" or "flood". At the times of high tide and low tide, the tide is said to be "turning".\n\n \nThe height of the high and low tides (relative to mean sea level) also varies. Around new and full Moon when the Sun, Moon and Earth form a line, the tidal forces due to the Sun reinforce those of the Moon, due to the syzygy found at those times.\n\nThe tides' range is then at its maximum: this is called the "spring tide", or just "springs" and is derived not from the season of spring but rather from the German verb springen, meaning "to leap up". When the Moon is at first quarter or third quarter, the sun and moon are at 90° to each other and the forces due to the Sun partially cancel out those of the Moon. At these points in the Lunar cycle, the tide's range is at its minimum: this is called the "neap tide", or "neaps".\n\nSpring 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. Normally there is a seven day interval between springs and neaps.\n\nThe relative distance of the Moon from the Earth also affects tide heights: When the Moon is at perigee the range increases, and when it is at apogee the range is reduced. Every 7½ lunations, perigee and (alternately) either a new or full Moon coincide; at these times the range of tide heights is greatest of all, 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 (surfers are aware of this, and will often intentionally go out to sea during these times, as the waves are more spectacular than ever). The effect is enhanced even further if the line-up of the Sun, Earth and Moon is so exact that a solar or lunar eclipse occurs concomitant with perigee.
640598
Tides are caused by factors such as winds, earths rotation and the sun and the moon's gravitational pull. All of them combined sometimes.\n\nexceptional cases such as tsunami-when sections of plates of earth's crust undergo changes such as shift, quakes, displacements