Harbour is the spelling to use when writing to a British audience. There are artificial harbors as well as natural ones. Poole Harbour Since Sydney reclaimed so much land from its harbour Poole Harbour is now the largest in the world. For a natural harbor, choose a place well protected from waves and wind, surrounded on several sides by land areas. Correct Option: A Kochi also has a natural harbour.
It is an artificial and allweather port with wet docks. Natural harbour: A landform where a portion of ocean or sea is protected and is so deep to allow vessels to take refuge.
Artificial harbour: An arrangement, which is so constructed to perform the functions of a port. Natural harbors are surrounded by land on most sides and have entrance points to the sea while an artificial harbor is a constructed platform that may serve as a port.
Harbors can also be used for recreational facilities for yacht owners. The size of the harbor depends on the number of vessels stored. It is considered one of the finest artificial harbors in the world. Construction of the harbor began in the mids, and continued until the mids. Now, the busy harbor import s and export s such cargo as oil , cars, and consumer goods like clothes and software. The Chennai harbor also loads and unloads thousands of tourists, from throughout India, Australia, and the tropical islands of the Indian Ocean like Maldives and Seychelles.
Like Chennai, many harbors may serve as port s manmade structures where ships load and unload cargo. For this reason, they are often vital to trade. When they function as ports, harbors often have artificial structures such as docks or jetties, as well as lighthouse s, buoy s, and other aids to navigation.
The large size of modern vessels requires that harbors have deep ship channels. Harbors have played an important role in civilization ever since people began using boats and ships at sea. Some 2, years ago, for instance, the Roman leader in what was then Palestine created a magnificent harbor at his city Caesarea Maritima. The ruins of this harbor, called Sebastos, are located on the Mediterranean Sea in present-day Israel. The Sebastos harbor relied heavily on breakwaters constructed from a unique form of concrete: a type of volcanic ash that hardened when mixed with seawater.
These breakwaters at Sebastos were called moles. Sebastos set a standard for future harbors. Most harbors were not improved until the mids. As commerce increased and ships grew bigger, enlarging and deepening harbors became necessary. Modern harbors range from small enclosures to huge commercial ports. Harbors can be one of the most pollute d ocean ecosystem s. Human activity from both land and sea contribute to the pollutant s.
Because harbors are partially enclosed, the pollution has nowhere to go. It builds up in both the seawater and the sediment below. One source of pollution is ship discharge. This discharge can be anything from sewage and wastewater used for cleaning to chemical materials used for packing cargo. The cargo itself can break and spill into the water, releasing plastic s, metals, and other toxic materials into the environment.
Harbors often have to be dredged to clean up the accumulate d waste and clear the channel for ships to pass through. Photograph by Duncan Brain , MyShot. Mulberry Harbours Mulberry Harbours were temporary, artificial harbors planned by military engineers from the United States and United Kingdom.
The U. Mulberry Harbours were more than breakwaters. They included docks for huge military transport ships, bridges, and more than 15 kilometers 10 miles of roads. Mulberry Harbour cargo included tanks, jeeps, engineering supplies like tents and tables , and food.
The most important cargo unloaded at Mulberry Harbours, however, were millions of troop reinforcementssoldiers. Buoys are often equipped with signals. Also known as petroleum or crude oil. The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit.
The Rights Holder for media is the person or group credited. Caryl-Sue, National Geographic Society. Dunn, Margery G. For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource.
If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media. Text on this page is printable and can be used according to our Terms of Service.
0コメント