Where are short distance surface currents located

the shoreline id assume

Explanation:

its most reliable

Ocean water is constantly moving, and not only in the form of waves and tides. Ocean currents flow like vast rivers, sweeping along predictable paths. Some ocean currents flow at the surface; others flow deep within water. Some currents flow for short distances; others cross entire ocean basins and even circle the globe.

By moving heat from the equator toward the poles, ocean currents play an important role in controlling the climate. Ocean currents are also critically important to sea life. They carry nutrients and food to organisms that live permanently attached in one place, and carry reproductive cells and ocean life to new places.

Rivers flow because of gravity. What makes ocean currents flow?

Tides contribute to coastal currents that travel short distances. Major surface ocean currents in the open ocean, however, are set in motion by the wind, which drags on the surface of the water as it blows. The water starts flowing in the same direction as the wind.

But currents do not simply track the wind. Other things, including the shape of the coastline and the seafloor, and most importantly the rotation of the Earth, influence the path of surface currents.  

In the Northern Hemisphere, for example, predictable winds called trade winds blow from east to west just above the equator. The winds pull surface water with them, creating currents. As these currents flow westward, the Coriolis effect—a force that results from the rotation of the Earth—deflects them. The currents then bend to the right, heading north. At about 30 degrees north latitude, a different set of winds, the westerlies, push the currents back to the east, producing a closed clockwise loop.

The same thing happens below the equator, in the Southern Hemisphere, except that here the Coriolis effect bends surface currents to the left, producing a counter-clockwise loop.  

Large rotating currents that start near the equator are called subtropical gyres. There are five main gyres: the North and South Pacific Subtropical Gyres, the North and South Atlantic Subtropical Gyres, and the Indian Ocean Subtropical Gyre.  

These surface currents play an important role in moderating climate by transferring heat from the equator towards the poles. Subtropical gyres are also responsible for concentrating plastic trash in certain areas of the ocean.

In contrast to wind-driven surface currents, deep-ocean currents are caused by differences in water density. The process that creates deep currents is called thermohaline circulation—“thermo” referring to temperature and “haline” to saltiness.

It all starts with surface currents carrying warm water north from the equator. The water cools as it moves into higher northern latitudes, and the more it cools, the denser it becomes.  

In the North Atlantic Ocean, near Iceland, the water becomes so cold that sea ice starts to form. The salt naturally present in seawater does not become part of the ice, however. It is left behind in the ocean water that lies just under the ice, making that water extra salty and dense. The denser water sinks, and as it does, more ocean water moves in to fill the space it once occupied. This water also cools and sinks, keeping a deep current in motion.

This is the start of what scientists call the “global conveyor belt,” a system of connected deep and surface currents that moves water around the globe. These currents circulate around the globe in a thousand-year cycle.

Explanation:

according to the denotation of “repeat,” history can’t repeat itself. (and if you want to get technical and into chaos theory, neither can anything else.) unlike lab-controlled experiments that can be exactly replicated (although not really), humans are life is always evolving and unpredictable and involves incalculable symbiotic relationships.

but, if we consider “repeat” as both a metaphor and in terms of its connotation, we can understand what people mean by “history repeats itself,” and it actually emerges as a useful conceptual tool. as mark twain put it, “history does not repeat itself, but it does rhyme.”

the vast, vast majority of people don’t in anyway think that history literally, exactly repeats itself. such would violate celebrated philosophies of free will. when people say that history repeats itself, they are generally thinking of broad patterns. another way to describe these patterns or relationships would be to describe them as cause and effect relationships. they are thinking about the existence of and continuation of

war,

poverty,

colonialism,

racism,

sexism,

classism, or

social movements, to list only a few of the repeated/unending phenomena of human history.a more specific example could be that every step forward in the long african-american civil rights movement has resulted in new forms of discrimination. lynching, disenfranchisement, and neo-enslavement (collectively called “jim crow”) replaced codified plantation and urban enslavement after the civil war and reconstruction era. today, the “new jim crow” (a system where by at least 1 out of every 3 black men are confined in the criminal justice system) replaced jim crow after the modern civil rights movement of the 1940s, 50s, and 60s.

people remain “babies” on the evolutionary ladder – we are greedy, shortsighted, and quick to buy into fear of “the other.” spending time trying to argue that history doesn’t repeat is ultimately not very productive for historians, a debate primarily involving semantic differences.

furthermore, if nothing “repeated,” it would quickly become impossible to study anything. much of what we study is about relationships between times and places. on the other hand, if we “dig deep,” language repeats all the time per se. if we had to relearn language every day, we would never progress. by saying “history repeats,” we are recognizing the ways in which we are bound to this world and products of it. this is not to say that nothing ever improves or changes.

as historians, we can and should use the real meanings behind notions that history repeats to students enjoy and embrace the study of our world. indeed one of the many reasons i enjoy studying history, as i tell students in my “what is history? ” lecture, is that history is comforting and allows us to see the world as a more steady place. according to the news and joe public, crime, poverty, you name it, are worse now than it ever has been. if we look at historical evidence, we can find that such fears are unnecessary. likewise, every generation says the previous generation had it better or older adults long for the time when they were adolescents when the world was a better, safer place (i call this the myth of the utopia past).  

finally, although human events can never come close to any kind of true replication, history belongs to both the liberal arts and the sciences. that history is a liberal art needs no explanation. that history is also a science, however, is where i tend to meet objections.

scientists follow the scientific method. they follow a series of steps to ensure their work is the best it can be given current resources. don’t historians do this? historians come up with questions, look for evidence, analyze evidence, weave in secondary material, write and edit, edit some more, and then go through peer-reviewers both informally and formally. this is indeed the historian’s equivalent of the scientific method. historical narratives or theories about the past are no more or less theories or narratives as human evolution or the big bang, for example. all scholarship involves theory and explanation based on evidence.

likewise, for reasons i haven’t fully grasped or studied yet, science tends to have more credibility with the public. people tend to perceive history as always changing, unstable, and inherently biased by “crazy, liberal academics.” in reality, science changes just as much, is just as unstable, and has just as many biases. in other words, history and any of the specific branches of science are all social constructions- both the discipline themselves and scholarship produced. by promoting the study of the past as a science, perhaps historians would have more automatic credibility.

be sure to check out: the nature of history and the history of history, i am many things but a “history buff” is not one of them. – hidden power of words series, #14, and my other postings about history, too!

explanation:

the emancipation proclamation was the aim of the war change to include the freeing of slaves in addition to preserving the union. the 13th amendment, which abolished slavery in the u.s. was passed on december 6th 1865.

as promised, lincoln waited to unveil the proclamation until he could do so with success from the union military advance. on september 22nd 1862, after a victory at antietam, he publicly announced a preliminary emancipation proclamation, declaring all slaves free in the rebellious states as of january 1st 1863.