The best Tides and Currents Tidal currents application on the market! Completely free! With more than stations covering all the world. Discover our fantastic interactive graphs with detailed infos presented to you with an awesome graphic style. This ocean motion is called the "great ocean conveyor belt.
Without it, the equator would be way too hot and the northern and southern parts of the planet might be frozen all the time. As Earth gets warmer, less ice forms in the Arctic each winter and more ice melts in the summer. How are these changes in the ocean's surface temperature and saltiness—or salinity—affecting the ocean currents?
How is the melting and heating affecting the average sea level? NASA spacecraft are collecting information about ocean temperature and salinity all the time. The information they collect will help scientists find the answers to these questions—and more! This information can help us better understand when and how the ocean currents are changing. If you liked this, you may like: Write your own zany adventure story!
Space Volcanoes! Not all currents occur at such a large scale. Individual beaches may have rip currents that are dangerous to swimmers. Rip currents are strong, narrow, seaward flows of water that extend from close to the shoreline to outside of the surf zone. Rip currents are formed when there are alongshore variations in wave breaking.
In particular, rip currents tend to form in regions with less wave breaking sandwiched between regions of greater wave breaking. This can occur when there are gaps in sand bars nearshore, from structures like piers or jetties, or from natural variations in how waves are breaking.
Rip currents can move faster than an Olympic swimmer can swim, at speeds as fast as eight feet 2. At these speeds, a rip current can easily overpower a swimmer trying to return to shore. Instead of attempting to swim against the current, experts suggest not to fight it and to swim parallel to shore.
Unseen by the human eye, thousands of microscopic animals hitch rides across oceans on an oceanic highway. These animals, called zooplankton, move at the whim of ocean currents. The currents enable the young creatures to find their way to hospitable places where they grow into adults. Other ocean creatures hitch rides on currents using floating debris, like mats of seaweed, tree trunks, and even plastic.
They use these havens to survive the otherwise perilous open ocean. After the tsunami that prompted the Fukushima Daiichi power plant meltdown in Japan, debris from the Japanese coast began washing ashore on the West coast of North America, bringing with it over Japanese species.
It also ensures the diversity of genetics within a population, an important factor for keeping species resistant and resilient to hardships like disease and environmental disasters. Currents also influence where large adult species can and want to go. Turtles and whales migrate annually to the plentiful waters of Georges Bank off the coast of New England, a place that is productive because of the warm waters brought north from the equator.
Sculpting seawater into crested shapes, waves move energy from one area to another. When waves crash onshore they can make a significant impact to the landscape by shifting entire islands of sand and carving out rocky coastlines.
Storm waves can even move boulders the size of cars above the high tide line, leaving a massive boulder hundreds of feet inland. Until recently, scientists attributed the placement of these rogue boulders to past tsunami damage, however, a study upended this notion by carefully recording the movement of boulders along a swath of rocky coastline in Ireland over a time period in which no tsunamis occurred. In addition to over 1, mid-sized boulders, many reaching over tons in weight, scientists recorded the movement of a ton boulder the same weight as 90 full-sized African elephants , showing that storm waves moved it over 8 feet 2.
A wave forms in a series of crests and troughs. The crests are the peak heights of the wave and the troughs are the lowest valleys. A wave is described by its wavelength or the distance between two sequential crests or two sequential troughs , the wave period or the time it takes a wave to travel the wavelength , and the wave frequency the number of wave crests that pass by a fixed location in a given amount of time.
When a wave travels, it is passing through the water, but the water barely travels, rather it moves in a circular motion. Waves on the ocean surface are usually formed by wind. When wind blows, it transfers the energy through friction.
The faster the wind, the longer it blows, or the farther it can blow uninterrupted, the bigger the waves. Therefore, a wave's size depends on wind speed, wind duration, and the area over which the wind is blowing the fetch. This variability leads to waves of all shapes and sizes. The smallest categories of waves are ripples, growing less than one foot. The largest waves occur where there are big expanses of open water that wind can affect. These large wave sites attract surfers, although occasionally, waves get just too big to surf.
Some of the biggest waves are generated by storms like hurricanes. In , Hurricane Ivan created waves that averaged around 60 feet 18 meters high and the largest were almost feet In , hurricane Dorian also created a wave over feet high in the northern Atlantic.
To sailors, they look like walls of water. No one knows for sure what causes a rogue wave to appear, but some scientists think that they tend to form when different ocean swells reinforce one another. One was recorded by a buoy in and measured A classic tsunami wave occurs when the tectonic plates beneath the ocean slip during an earthquake.
The physical shift of the plates force water up and above the average sea level by a few meters. From a single tectonic plate slip, waves radiate outwards in all directions moving away from the earthquake. When a tsunami reaches shore, it begins to slow dramatically from contact with the bottom of the seafloor.
As the leading part of the wave begins to slow, the remaining wave piles up behind it, causing the height of the wave to increase. Though tsunami waves are only a few feet to several meters high as they travel over the deep ocean, it is their speed and long wavelength that cause the change to dramatic heights when they are forced to slow at the shore.
Tsunami waves are capable of destroying seaside communities with wave heights that sometimes surpass around 66ft 20 m. Tsunamis have caused over , deaths since —over , people were killed by the giant earthquake off Indonesia in , and the damage caused to the Fukushima nuclear reactor in Japan by a tsunami in continues to wreak havoc. The highest tsunami wave reached about 1, ft m , a product of a massive earthquake and rockslide.
When the wave hit shore, it was said to destroy everything. There are also other, usually less destructive tsunami waves caused by weather systems called meteotsunamis. Surface currents are propelled by the wind, and deep ocean currents are driven by different levels of density in the water.
The cooler and saltier the water, the denser it is. Sunlight heats water, so the different amounts of sunlight in different parts of the world change the water temperature. This helps them map global current systems, allowing us to understand how water moves and how it affects the environment. A preview of each game in the learning objective is found below.
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