Caribbean Sea
May 27th, 2008
The name "Caribbean" is originated from the Caribs, one of the dominant American Indian groups in the region at the time of European contact during the late 15th century. After the discovery of the West Indies by Christopher Columbus in 1492, the Spanish term Antillas was commonly assigned to the lands; stemming from this, "Sea of the Antilles" is a common alternative name for the Caribbean Sea in various European languages. During the first century of development, the Spanish dominance was undisputed. The Caribbean Sea was an unknown body of water to the populations of Eurasia until 1492 when Christopher Columbus first sailed into Caribbean waters while trying to find a route to India. At that time the Western Hemisphere in general was unknown to Europeans. Following the discovery of the islands by Columbus, the area was quickly colonized by several Western Civilizations. Following the colonization of the Caribbean islands, the Sea became a busy area for European-based marine trading and transport, and this commerce eventually attracted piracy. Today the area is home to 22 island territories and borders 12 continental countries. Because of an abundance of sunshine, year-round tropical temperatures moderated by the almost constant trade winds, and the great variety of scenic destinations to visit, during the second half of the 20th century on into the 21st, the Caribbean Sea became a popular place for tourism, and this trend has favored the increasing development of the cruise industry in the area.
The Caribbean is the setting for countless literary efforts often related to piracy and swashbuckling. One memorable work of pulp fiction has in its title a geographic feature unique in its way to the islands: Fear Cay, the eleventh Doc Savage adventure by Lester Dent. Many James Bond adventures were set there. It is also well known as the location of the Pirates of the Caribbean films, featuring Port Royal.
The Caribbean Sea is an oceanic sea largely situated on the Caribbean Plate. Estimates of the sea's age range from 20,000 years to 570 million years. The Caribbean sea floor is divided into five basins separated from each other by underwater ridges and mountain ranges. Atlantic Ocean enters the Caribbean through the Anegada Passage lying between the Lesser Antilles and Virgin Islands and the Windward Passage located between Cuba and Haiti. The deepest points of the sea lie in Cayman Trough with depths reaching approximately 7,686 m (25,220 ft). Despite this, the Caribbean Sea is considered a relatively shallow sea in comparison to other bodies of water. The Caribbean sea floor is also home to two oceanic trenches: the Hispaniola Trench and Puerto Rico Trench, which put the area at a higher risk of earthquakes. Underwater earthquakes pose a threat of generating tsunamis which could have a devastating effect on the Caribbean islands. Scientific data reveals that over the last 500 years the area has seen a dozen earthquakes above 7.5 magnitude.
The Caribbean weather is influenced by the Gulf Stream and Humboldt Current ocean currents. The tropical location of the sea helps the water to maintain a warm temperature ranging from the low of 70 to mid-80 degrees Fahrenheit by the season. The Caribbean is a focal area for many hurricanes within the Western Hemisphere. A series of low pressure systems develop off the West coast of Africa and make their way across the Atlantic Ocean. While most of these systems do not become tropical storms, some do. The tropical storms can develop into Atlantic hurricanes, often in the low pressure areas of the eastern Caribbean. The Caribbean hurricane season as a whole lasts from June to December, with the majority of hurricanes occurring during August and September. On average around 9 tropical storms form each year, with 5 reaching hurricane strength. According to the National Hurricane Center 385 hurricanes occurred in the Caribbean between 1494 and 1900. Every year hurricanes represent a potential threat to the islands of the Caribbean, due to the extremely destructive nature of these powerful weather systems. Coral reefs can easily be damaged by violent wave action, and can be destroyed when a hurricane dumps sand or mud onto the a reef. When this happens, the coral organisms are smothered and the reef dies and ultimately breaks apart.
The Caribbean is home to about 29% of the world's coral reefs covering about 20,000 square miles (50,000 km²), most of which are located off the Caribbean Islands and the Central American coast. Currently, unusually warm Caribbean waters are endangering the Caribbean coral reefs. Coral Reefs support some of the most diverse habitats in the world, but are fragile ecosystems. When tropical waters exceed 85 degrees Fahrenheit for an extended period of time, microscopic plants called zooxanthellae die off. These plant provide food for the coral and give them their color. The resultant bleaching of the coral reefs kills them, and ruins the ecosystem. Up to 42% of the coral colonies have gone completely white, while 95% have undergone at least some bleaching. The habitats supported by the reefs are critical to such tourist activities such as fishing and diving, and provide an annual economic value to Caribbean nations of $3.1-$4.6 billion. Continued destruction of the reefs could severely damage the region's economy. A Protocol of the Convention for the Protection and Development of the Marine Environment of the Wider Caribbean Region came in effect in 1986 to protect the various endangered marine life of the Caribbean through forbidding human activities that would advance the continued destruction of such marine life in various areas. Currently this protocol has been ratified by 15 countries. Also several charitable organizations have been formed to preserve the Caribbean marine life, such as Caribbean Conservation Corporation which seeks to study and protect sea turtles while educating others about them.
The Caribbean region has seen a considerable increase in human activity since the colonization period. The sea is one of the biggest oil production areas in the world, producing about 170 million tons per year. The area also generates a large fishing industry for the surrounding countries, accounting for half a million metric tons of fish a year. Human activity in the area also accounts for a significant amount of pollution, Pan American Health Organization estimating in 1993 that only about 10% of the sewage from the Central American and Caribbean Island countries is properly treated before being released into the Sea. The Caribbean region supports a large tourist industry. The Caribbean Tourism Organization analyzed that about 12 million people a year visit the area, including (in 1991–1992) about 8 million Cruise Ship tourists.
Black Sea
April 28th, 2008
Countries bordering the Black Sea are: Turkey, Romania, Bulgaria, Ukraine, Russia, and Georgia. The Crimean peninsula is an autonomous republic of Ukraine. Russia leases a navy base in Sevastopol from Ukraine as a result of the partition of the Black Sea Fleet after the fall of the Soviet Union. The lease of the navy base by Russia in Sevastopol is set to expire in 2017, and is not scheduled for renewal.
Important cities along the coast include: Burgas, Varna, Constanţa, Odessa, Kherson, Sevastopol, Yalta, Kerch, Novorossiysk, Sochi, Sukhumi, Poti, Batumi, Trabzon, Samsun and Zonguldak (104,276).
The Black Sea was a busy waterway on the crossroads of the ancient world: the Balkans to the West, the Eurasian steppes to the north, Caucasus and Central Asia to the East, Asia Minor and Mesopotamia to the south, and Greece to the south-west. The oldest processed gold in the world, arguably left by Old Europeans, was found in Varna, and the Black Sea was supposedly sailed by the Argonauts. The land at the eastern end of the Black Sea, Colchis, (now Georgia), marked for the Greeks an edge of the known world. The steppes to the north of the Black Sea have been suggested as the original homeland (Urheimat) of the speakers of the Proto-Indo-European language, (PIE) the progenitor of the Indo-European language family, by some scholars (see Kurgan; others move the heartland further east towards the Caspian Sea, yet others to Anatolia). Numerous ancient ports line Black Sea's coasts, some older than the pyramids. Ancient trade routes in the region are currenly being extensively studied by American, Bulgarian, and other scientists. It is widely believed that the Black Sea is packed with archaeology to be found. Perhaps the most promising areas in deepwater archaeology are the quest for submerged prehistoric settlements in the continental shelf and for ancient shipwrecks in the anoxic zone, which are expected to be exceptionally well preserved due to the absence of oxygen. The Black Sea was a significant naval theatre of World War I and saw both naval and land battles of the World War II. The Black Sea has witnessed the rivalries of Hittites, Carians, Thracians, Greeks, Persians, Scythians, Romans, Byzantines, Goths, Huns, Avars, Bulgars, Slavs, Varangians, Crusaders, Venetians, Genovese, Tatars, Ottomans, and Russians.
The Black Sea forms an enclosed basin, located between south-eastern Europe and Asia Minor. The basin was formed during the Miocene orogenies which uplifted the mountain ranges and divided the ancient Tethys Ocean into several brackish basins, including the Sarmatic Sea. The Caspian, Azov, Aral and Black Seas are the remnants of this evaporated basin. The basin is divided into two sub-basins by a convexity extending south from the Crimean peninsula. The north-west of the basin is characterized by a relatively large shelf up to 190 km (120 mi) wide, which has a relatively shallow apron with gradients between 1:40 and 1:1000. The southern edge around Turkey and the eastern edge around Georgia, however, are typified by a shelf that rarely exceeds 20 km (12 mi) in width and an apron that is typically 1:40 gradient with numerous submarine canyons and channel extensions. The Euxine abyssal plain in the centre of the Black Sea reaches a maximum depth of 2,206 m (7,240 ft) just south of Yalta on the Crimean peninsula. The basin is connected to the Mediterranean Sea via the Turkish Straits System (TSS) in the south-west, which includes the Bosporus and Dardanelles straits and the Sea of Marmara. The Black Sea is connected to the Sea of Azov in the north-east via the Kerch straits.
The Black Sea is the world’s largest meromictic basin where the deep waters do not mix with the upper layers of water that receive oxygen from the atmosphere. As a result, over 90% of the deeper Black Sea volume is anoxic water. The current hydrochemical configuration is primarily controlled by basin topography and fluvial inputs, which result in a strongly stratified vertical structure and a positive water balance. The upper layers are generally cooler, less dense and less salty than the deeper waters, as they are fed by large fluvial systems, whereas the deep waters originate from the warm, salty waters of the Mediterranean. This influx of dense water from Mediterranean is balanced by an outflow of fresher Black Sea surface-water into the Marmara Sea, maintaining the stratification and salinity levels. The surface water has an average salinity of 18 to 18.5 parts per thousand and contains oxygen and other nutrients required to sustain biotic activity. These waters circulate in a basin-wide cyclonic shelfbreak gyre known as the Rim Current which transports water round the perimeter of the Black Sea. Within this feature, two smaller cyclonic gyres operate, occupying the eastern and western sectors of the basin. Outside the Rim Current, numerous quasi-permanent coastal eddies are formed due to upwelling around the coastal apron and ‘wind curl’ mechanisms. The intra-annual strength of these features is controlled by seasonal atmospheric and fluvial variations. Sea Surface Temperature of the surface waters varies seasonally from 8 °C (46 °F) to 30 °C (86 °F).
Directly beneath the surface waters the Cold Intermediate Layer (CIL) is found. This layer is composed of cool, salty surface waters, which are the result of localised atmospheric cooling and decreased fluvial input during the winter months. The production of this water is focussed in the centre of the major gyres and on the NW shelf and as the water is not dense enough to penetrate the deep waters, isopycnal advection occurs, dispersing the water across the entire basin. The base of the CIL is marked by a major thermocline, halocline and pycnocline at ~100-200 m and this density disparity is the major cause of deep water isolating.
Below the pycnocline, salinity increases to 22 to 22.5 ppt and temperatures rise to around 8.5 °C (47.3 °F). The hydrochemical environment shifts from oxygenated to anoxic, as bacterial decomposition of sunken biomass utilises all of the free oxygen. Organic matter, including anthropogenic artefacts such as boat hulls, are well preserved. During periods of high surface productivity, short-lived algal blooms cause organic rich layer known as sapropels to occur. Scientists have reported an annual phytoplankton bloom that can be seen in many NASA images of the region. Another danger to people posed by the anoxic layer could come from a small asteroid's impact into the Black Sea. Recently modelling shows there is a significant threat to life for people living on the sea's shore.
What is the future of the Black Sea? Nitrogen inputs into the Black Sea have been reduced recently, but are still higher as those observed during the 1960s; current phosphate inputs appear to be roughly the same as in the 1960s. According to information from the Black Sea Commission efforts to reduce discharges from 49 high priority pollution sources, pollution from insufficiently treated waste water and airborne emissions in all the Black Sea coastal states are beginning to bear fruit, since fewer and less intense algal blooms are now being recorded in the sea, while total fish catches have increased. Pollution from municipalities and industry is clearly declining due to the following factors: economic recession in the lower Danubian and former Soviet countries; successful measures taken to reduce nutrient discharges in the upper Danube countries, including dramatic reductions in the use of fertilizers and considerable improvements in the treatment of waste water; the implementation of a ban on polyphosphate detergents in some countries.
The Celebes Sea
March 27th, 2008
The Celebes Sea is a piece of an ancient ocean basin that formed 42 million years ago in a setting far from any land mass. By 20 million years ago, crustal movement had pushed the Celebes basin close enough to the Indonesian and Philippine volcanoes to receive volcanic debris. By 10 million years ago the Celebes Sea was inundated with continental debris, including coal, which was shed from a rapidly growing young mountain on Borneo and the basin had docked against Eurasia.
The border between the Celebes and the Sulu Sea is at the Sibutu-Basilan Ridge. Strong ocean currents, deep sea trenches and seamounts, combined with active volcanic islands, result in complex oceanographic features.
Celebes Sea pirates. The Celebes Sea has somewhat attained an international notoriety for its pirates who prey not only on small time fishermen but also giant container ships. Nowadays, these pirates have high-tech weapons and equipment like radar and GPS navigation devices and ride on high-speed motorboats.
Marine life. The Celebes Sea is home to a wide variety of fish and aquatic creatures. The tropical setting and warm clear waters permit it to harbor about 580 of the world's 793 species of reef-building corals, which grow as some of the most bio-diverse coral reefs in the world, and an impressive array of marine life, including whales and dolphins, sea turtles, manta rays, eagle rays, barracuda, marlin and other reef and pelagic species. Tuna and yellow fin tuna are also abundant. In addition to high abundance of fish caught in the Celebes sea, this sea also yields other aquatic products like sea tang.
