Yahoo Web Search

  1. About 294,000 search results
  1. The Mediterranean Sea covers an area of about 2,500,000 km 2 (970,000 sq mi), representing 0.7% of the global ocean surface, but its connection to the Atlantic via the Strait of Gibraltar—the narrow strait that connects the Atlantic Ocean to the Mediterranean Sea and separates Spain in Europe from Morocco in Africa—is only 14 km (9 mi) wide.

    • 1,500 m (4,900 ft)
    • 2,500,000 km² (970,000 sq mi)
  2. The Mediterranean Sea is the body of water that separates Europe, Africa, and Asia. The Mediterranean Sea is connected to the Atlantic Ocean by a narrow passage called the Strait of Gibraltar. The sea is almost completely surrounded by land, on the north by Europe, on the south by North Africa, and on the east by the Middle East. It covers ...

  3. People also ask

    How is the Mediterranean Sea connected to Europe?

    What is the temperature of water in the Mediterranean Sea?

    How big is the Mediterranean Sea in square miles?

    What was the ancient Egyptian name for the Mediterranean Sea?

  4. The Antikythera mechanism ( / ˌæntɪkɪˈθɪərə / AN-tih-kih-THEER-ə) is an ancient Greek hand-powered orrery, described as the oldest example of an analogue computer used to predict astronomical positions and eclipses decades in advance. It could also be used to track the four-year cycle of athletic games which was similar to an Olympiad ...

  5. › wiki › Naval_mineNaval mine - Wikipedia

    • Description
    • History
    • Mine Laying
    • Damage
    • Countermeasures
    • National Arsenals
    • Modern Mine Warfare
    • References
    • External Links

    Mines can be laid in many ways: by purpose-built minelayers, refitted ships, submarines or aircraft—and even by dropping them into a harbour by hand. They can be inexpensive: some variants can cost as little as US$2,000, though more sophisticated mines can cost millions of dollars, be equipped with several kinds of sensors and deliver a warhead by rocket or torpedo. Their flexibility and cost-effectiveness make mines attractive to the less powerful belligerent in asymmetric warfare. The cost of producing and laying a mine is usually between 0.5% and 10% of the cost of removing it, and it can take up to 200 times as long to clear a minefield as to lay it. Parts of some World War II naval minefields still exist because they are too extensive and expensive to clear.Some 1940s-era mines may remain dangerous for many years. Mines have been employed as offensive or defensive weapons in rivers, lakes, estuaries, seas and oceans, but they can also be used as tools of psychological warfare....

    Early use

    Precursors to naval mines were first invented by Chinese innovators of Imperial China and were described in thorough detail by the early Ming dynasty artillery officer Jiao Yu, in his 14th-century military treatise known as the Huolongjing. Chinese records tell of naval explosives in the 16th century, used to fight against Japanese pirates (wokou). This kind of naval mine was loaded in a wooden box, sealed with putty. General Qi Jiguang made several timed, drifting explosives, to harass Japan...

    19th century

    In 1812, Russian engineer Pavel Shilling exploded an underwater mine using an electrical circuit. In 1842 Samuel Colt used an electric detonator to destroy a moving vessel to demonstrate an underwater mine of his own design to the United States Navy and President John Tyler. However, opposition from former president John Quincy Adams, scuttled the project as "not fair and honest warfare". In 1854, during the unsuccessful attempt of the Anglo-French fleet to seize the Kronstadt fortress, Briti...

    Early 20th century

    During the Boxer Rebellion, Imperial Chinese forces deployed a command-detonated mine field at the mouth of the Peiho river before the Dagu forts, to prevent the western Allied forcesfrom sending ships to attack. The next major use of mines was during the Russo-Japanese War of 1904–1905. Two mines blew up when the Petropavlovsk struck them near Port Arthur, sending the holed vessel to the bottom and killing the fleet commander, Admiral Stepan Makarov, and most of his crew in the process. The...

    Historically several methods were used to lay mines. During WWI and WWII, the Germans used U-boats to lay mines around the UK. In WWII, aircraft came into favour for mine laying with one of the largest examples being the mining of the Japanese sea routes in Operation Starvation. Laying a minefield is a relatively fast process with specialized ships, which is today the most common method. These minelayers can carry several thousand mines[citation needed]and manoeuvre with high precision. The mines are dropped at predefined intervals into the water behind the ship. Each mine is recorded for later clearing, but it is not unusual for these records to be lost together with the ships. Therefore, many countries demand that all mining operations be planned on land and records kept so that the mines can later be recovered more easily. Other methods to lay minefields include: 1. Converted merchant ships – rolled or slid down ramps 2. Aircraft – descent to the water is slowed by a parachute 3....

    The damage that may be caused by a mine depends on the "shock factorvalue", a combination of the initial strength of the explosion and of the distance between the target and the detonation. When taken in reference to ship hull plating, the term "Hull Shock Factor" (HSF) is used, while keel damage is termed "Keel Shock Factor" (KSF). If the explosion is directly underneath the keel, then HSF is equal to KSF, but explosions that are not directly underneath the ship will have a lower value of KSF.

    Weapons are frequently a few steps ahead of countermeasures, and mines are no exception. In this field the British, with their large seagoing navy, have had the bulk of world experience, and most anti-mine developments, such as degaussing and the double-L sweep, were British inventions. When on operational missions, such as the recent invasion of Iraq, the US still relies on British and Canadian minesweeping services. The US has worked on some innovative mine-hunting countermeasures, such as the use of military dolphins to detect and flag mines. However, they are of questionable effectiveness.[citation needed] Mines in nearshore environments remain a particular challenge. They are small and as technology has developed they can have anechoic coatings, be non-metallic, and oddly shaped to resist detection.:18 Further, oceanic conditions and the sea bottoms of the area of operations can degrade sweeping and hunting efforts.:18 Mining countermeasures are far more expensive and time-cons...

    US mines

    The United States Navy MK56 ASW mine (the oldest still in use by the United States) was developed in 1966. More advanced mines include the MK60 CAPTOR(short for "encapsulated torpedo"), the MK62 and MK63 Quickstrike and the MK67 SLMM (Submarine Launched Mobile Mine). Today, most U.S. naval mines are delivered by aircraft. MK67 SLMM Submarine Launched Mobile Mine The SLMM was developed by the United States as a submarine deployed mine for use in areas inaccessible for other mine deployment tec...

    Royal Navy

    According to a statement made to the UK Parliament in 2002: However, a British company (BAE Systems) does manufacture the Stonefish influence mine for export to friendly countries such as Australia, which has both war stock and training versions of Stonefish,[unreliable source?] in addition to stocks of smaller Italian MN103 Manta mines. The computerised fuze on a Stonefish mine contains acoustic, magnetic and water pressure displacement target detection sensors. Stonefish can be deployed by...

    Mine warfare remains the most cost-effective of asymmetrical naval warfare. Mines are relatively cheap and being small allows them to be easily deployed. Indeed, with some kinds of mines, trucks and rafts will suffice. At present there are more than 300 different mines available. Some 50 countries currently have mining ability. The number of naval mine producing countries has increased by 75% since 1988. It is also noted that these mines are of an increasing sophistication while even the older type mines present a significant problem. It has been noted that mine warfare may become an issue with terrorist organizations. Mining busy shipping straits and mining shipping harbors remain some of the most serious threats.:9


    1. This article incorporates text from Publication, Issue 33 Document (United States. War Dept.), by United States. Adjutant-General's Office. Military Information Division, a publication from 1901, now in the public domainin the United States. 2. This article incorporates text from Reports on military operations in South Africa and China. July, 1901, by United States. Adjutant-General's Office. Military Information Division, Stephen L'H. Slocum, Carl Reichmann, Adna Romanga Chaffee, a public...


    1. Hanning, Marcus A.; Smyers, Richard Paul & Thorne, Phil (2010). "Question 11/46: Japanese Use of Mines in WW II". Warship International. XLVII (2): 95–99. ISSN 0043-0374. 2. Macrae, Stuart (1971). Winston Churchill's Toyshop. Roundwood Press. ISBN 0-900093-22-6. 3. Needham, Joseph (1986). Science and Civilization in China: Volume 5, Part 7. Taipei: Caves Books, Ltd. 4. Tarle, Yevgeny (1944). Крымская война [Crimean War] (in Russian). II. Moscow: Soviet Academy of Sciences. 5. "WW2 People's...

    Further reading

    1. Hartmann, Gregory K.; Truver, Scott C. (1991). Weapons That Wait: Mine Warfare in the U.S. Navy. Annapolis: Naval Institute Press. ISBN 0-87021-753-4.(Canonical general text about U.S. mine warfare) 2. Hewitt, James Terrance (1998). Desert Sailor: A War of Mine. Clementsport: The Canadian Peacekeeping Press. ISBN 1-896551-17-3.(Personal account of mine countermeasures operations in Operation Desert Storm during the Gulf War 1991, including the mining of USS Tripoli.) 3. Peniston, Bradley (...

    • Early History: Telegraph and Coaxial Cables
    • Modern History
    • Cable Repair
    • Intelligence Gathering
    • Environmental Impact
    • Security Implications
    • Legal Issues
    • Influence of Cable Networks on Modern History
    • Notable Events
    • See Also

    First successful trials

    After William Cooke and Charles Wheatstone had introduced their working telegraph in 1839, the idea of a submarine line across the Atlantic Ocean began to be thought of as a possible triumph of the future. Samuel Morse proclaimed his faith in it as early as 1840, and in 1842, he submerged a wire, insulated with tarred hemp and India rubber, in the water of New York Harbor, and telegraphed through it. The following autumn, Wheatstone performed a similar experiment in Swansea Bay. A good insula...

    First commercial cables

    In August 1850, having earlier obtained a concession from the French government, John Watkins Brett's English Channel Submarine Telegraph Company laid the first line across the English Channel, using the converted tugboat Goliath. It was simply a copper wire coated with gutta-percha, without any other protection, and was not successful.:192–193 However, the experiment served to secure renewal of the concession, and in September 1851, a protected core, or true, cable was laid by the reconstitu...

    Transatlantic telegraph cable

    The first attempt at laying a transatlantic telegraph cable was promoted by Cyrus West Field, who persuaded British industrialists to fund and lay one in 1858. However, the technology of the day was not capable of supporting the project; it was plagued with problems from the outset, and was in operation for only a month. Subsequent attempts in 1865 and 1866 with the world's largest steamship, the SS Great Eastern, used a more advanced technology and produced the first successful transatlantic...

    Optical telecommunications cables

    In the 1980s, fibre-optic cables were developed. The first transatlantic telephone cable to use optical fibre was TAT-8, which went into operation in 1988. A fibre-optic cable comprises multiple pairs of fibres. Each pair has one fibre in each direction. TAT-8 had two operational pairs and one backup pair. Modern optical fibre repeaters use a solid-state optical amplifier, usually an Erbium-doped fibre amplifier. Each repeater contains separate equipment for each fibre. These comprise signal...

    Importance of submarine cables

    Currently 99% of the data traffic that is crossing oceans is carried by undersea cables. The reliability of submarine cables is high, especially when (as noted above) multiple paths are available in the event of a cable break. Also, the total carrying capacity of submarine cables is in the terabits per second, while satellites typically offer only 1,000 megabits per second and display higher latency. However, a typical multi-terabit, transoceanic submarine cable system costs several hundred m...

    Investment in and financing of submarine cables

    Almost all fibre-optic cables from TAT-8 in 1988 until approximately 1997 were constructed by consortia of operators. For example, TAT-8 counted 35 participants including most major international carriers at the time such as AT&T Corporation. Two privately financed, non-consortium cables were constructed in the late 1990s, which preceded a massive, speculative rush to construct privately financed cables that peaked in more than $22 billion worth of investment between 1999 and 2001. This was f...

    Cables can be broken by fishing trawlers, anchors, earthquakes, turbidity currents, and even shark bites. Based on surveying breaks in the Atlantic Ocean and the Caribbean Sea, it was found that between 1959 and 1996, fewer than 9% were due to natural events. In response to this threat to the communications network, the practice of cable burial has developed. The average incidence of cable faults was 3.7 per 1,000 km (620 mi) per year from 1959 to 1979. That rate was reduced to 0.44 faults per 1,000 km per year after 1985, due to widespread burial of cable starting in 1980. Still, cable breaks are by no means a thing of the past, with more than 50 repairs a year in the Atlantic alone, and significant breaks in 2006, 2008, 2009 and 2011. The propensity for fishing trawler nets to cause cable faults may well have been exploited during the Cold War. For example, in February 1959, a series of 12 breaks occurred in five American trans-Atlantic communications cables. In response, a United...

    Underwater cables, which cannot be kept under constant surveillance, have tempted intelligence-gathering organizations since the late 19th century. Frequently at the beginning of wars, nations have cut the cables of the other sides to redirect the information flow into cables that were being monitored. The most ambitious efforts occurred in World War I, when British and German forces systematically attempted to destroy the others' worldwide communications systems by cutting their cables with surface ships or submarines. During the Cold War, the United States Navy and National Security Agency (NSA) succeeded in placing wire taps on Soviet underwater communication lines in Operation Ivy Bells.

    The main point of interaction of cables with marine life is in the benthic zone of the oceans where the majority of cable lies. Studies in 2003 and 2006 indicated that cables pose minimal impacts on life in these environments. In sampling sediment cores around cables and in areas removed from cables, there were few statistically significant differences in organism diversity or abundance. The main difference was that the cables provided an attachment point for anemones that typically could not grow in soft sediment areas. Data from 1877 to 1955 showed a total of 16 cable faults caused by the entanglement of various whales. Such deadly entanglements have entirely ceased with improved techniques for placement of modern coaxial and fibre-optic cables which have less tendency to self-coil when lying on the seabed.

    Submarine cables are problematic from the security perspective because maps of submarine cables are widely available. Publicly available maps are necessary so that shipping can avoid damaging vulnerable cables by accident. However, the availability of the locations of easily damaged cables means the information is also easily accessible to criminal agents.Governmental wiretapping also presents cybersecurity issues.

    Submarine cables suffer from the inherent issues. Since cables are constructed and installed by private consortia, there is a problem with responsibility from the outset. Firstly, assigning responsibility inside a consortium can be hard: since there is no clear leading company which could be designated as responsible, it can lead to confusion when the cable needs maintenance. Secondly, it is hard to navigate the issue of cable damage through the international legal regime, since it was signed by and designed for nation states, rather than private companies. Thus it is hard to decide who should be responsible for damage costs and repairs - the company who built the cable, the company who paid for the cable, the government of the countries where the cable terminates. Another legal issue is the outdating of legal systems. For example, Australia still uses fines which were set during the signing of the 1884 submarine cable treaty: 2000 Australian dollars, almost insignificant now.

    Submarine communication cables have had a wide variety of influences over society. As well as allowing effective intercontinental trading and supporting stock exchanges, they greatly influenced international diplomatic conduct. Before the existence of submarine communication connection diplomats had much more power in their hands since their direct supervisors (governments of the countries which they represented) could not immediately check on them. Getting instructions to the diplomats in a foreign country often took weeks or even months. Diplomats had to use their own initiative in negotiations with foreign countries with only an occasional check from their government. This slow connection resulted in diplomats engaging in leisure activities while they waited for orders. The expansion of telegraph cables greatly reduced the response time needed to instruct diplomats. Over time, this led to a general decrease in prestige and power of individual diplomats within international politi...

    In 1914, Germany raided the Fanning Islandcable station in the Pacific. The Newfoundland earthquake of 1929 broke a series of transatlantic cables by triggering a massive undersea mudslide. The sequence of breaks helped scientists chart the progress of the mudslide. In 1986 during prototype and pre-production testing of the TAT-8 fiber-optic cable and its lay down procedures conducted by AT&T in the Canary Islandsarea, shark bite damage to the cable occurred. This revealed that sharks will dive to depths of 1 kilometre (0.62 mi), a depth which surprised marine biologists who until then thought that sharks were not active at such depths. The TAT-8 submarine cable connection was opened in 1988. In July 2005, a portion of the SEA-ME-WE 3 submarine cable located 35 kilometres (22 mi) south of Karachi that provided Pakistan's major outer communications became defective, disrupting almost all of Pakistan's communications with the rest of the world, and affecting approximately 10 million I...

    • Timeline of Greek History
    • Early History
    • Greco-Persian Wars
    • Athens Against Sparta
    • Daily Life
    • Ancient Greek Games
    • Other Websites

    The history of Greece went through these stages: 1. Mycenaean culture (c.1600–c.1100 BC) was an early Greek culture during the Bronze Age, on the Greek mainland and on Crete. 2. The bronze age collapse or Greek dark ages(c.1100–c.750 BC). 3. The archaic period (c.750–c.500 BC). Artists made larger free-standing sculptures in stiff poses, with the dreamlike 'archaic smile'. The archaic period ends with the overthrow of the last tyrant of Athensin 510 BC. 4. The classical period (c.500–323 BC) had a style which was considered by later observers to be an outstanding example (i.e. 'classical')—for instance the Parthenon. Politically, the classical period was dominated by Athens and the Delian League during the 5th century. They were displaced by Spartan hegemony during the early 4th century BC. Finally there was the League of Corinth, which was led by Macedon. 1. The Hellenistic period (323–146 BC) is when Greek culture (Hellenistic art) and power expanded into the near and Middle East....


    In the 8th century B.C., the Greeks learned how to read and write a second time. They had lost literacy at the end of the Mycenaean culture, as the Mediterranean world fell into the Dark Ages. The Greek Dark Ages (~1100 BC–750 BC), or Bronze Age collapse, is a period in the history of Ancient Greece and Anatoliafrom which there are no written records, and few archaeological remains. The Greeks learned about the alphabet from another ancient people, the Phoenicians. They made some adjustments...

    Political structure

    Ancient Greece had one language and culture, but was not unified until 337 BC, when Macedonia defeated Athens and Thebes. That marked the end of the Classic period, and the start of the Hellenistic period. Even then, the conquered cities were merely joined to Philip II of Macedon's Corinthian League; they were not occupied, and ruled themselves.

    In 499 BC, the Greek cities in Anatolia rebelled. They did not want Persia to rule them anymore. Athens sent 20 ships to fight the Persians on the sea. The Greeks in Anatolia were defeated. The Persian King, Dariusdecided to punish Athens. He sent soldiers and ships to fight Athens. Athens asked for help from Sparta. Sparta wanted to help but could not; they had a religious festival at that time. Athens sent her soldiers against the Persian soldiers: at the Battle of Marathon(490 BC) they defeated the Persians. Then the help from Sparta came. At the Battle of Thermopylae The Spartans were led by Leonidas, and resisted the huge Persian army. After a couple of days, a traitor called Ephialtes led the Persians around the pass behind the Greek army. Realising that defeat was inevitable, Leonidas released many of his men. Those who stayed knew it would be a fight to the death. Leonides kept elite hoplites (foot soldiers) who had living sons at home.There were also allied Thespians and Th...

    After the Persians were defeated at Platea, the Spartans did very little. However, Persia was still dangerous. Athens asked the Greek cities on the islands in the Aegean and in Anatolia to join her. The cities agreed because they were afraid of Persia. These cities formed the Delian League and Athens was their leader. Many of the cities of the Delian League had to pay Athens tribute money. Athens used the money to build many ships and the Parthenon. Sparta was still strong on land, but Athens was stronger on the sea. Several times there was war between Athens and Sparta. Then Athens decided to send many ships to Sicily to fight against the city Syracuse. Sparta sent help to Syracuse, and Athens was defeated. None of the Athenian ships came back. Now Sparta wanted to build ships to fight Athens. It took a long time for Sparta to defeat Athens, but then at the Battle of Aegospotami the Spartans destroyed most of Athens's ships. The Athenians used an advanced type of ship called trirem...

    Men, when not working, fighting or discussing politics, could (at festive times) go to Ancient Greek theatre to watch dramas, comedies or tragedies. These often involved politics and the gods of Greek mythology. Women were not allowed to perform in the theatre; male actors played female roles. Women did domestic work, such as spinning, weaving, cleaning and cooking. They were not involved in public life or politics. Women from rich families however, had slaves to carry out domestic work for them.

    The famous Olympic games were held at Olympia every four years. They were for men only, and women were not allowed to attend, even as spectators. The sports included running, javelin throwing, discus throwing and wrestling. The Games were unusual, because the athletes could come from any Greek city. Another competition, the Heraean Games, was held for women. It was also held at Olympus at a different time from the men's event. The rules for girls in Spartawere different from other cities. They were trained in the same events as boys, because Spartans believed that strong women would produce strong babies who would become future warriors. Their girl athletes were unmarried and competed nude or wearing short dresses. Boys were allowed to watch the athletes, in the hopes of creating marriages and offspring. Later, in the Classical period, girls could compete in the same festivals as males.

  1. People also search for