~ Mother Earth ~
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Contrail
Contrails are condensation trails (sometimes vapour trails): artificial cirrus clouds made by the exhaust of aircraft engines or wingtip vortices which precipitate a stream of tiny ice crystals in moist, frigid upper air.
A C-141 Starlifter leaves contrails or vapour trails over Antarctica.
Contrail creation
Contrails are created in one of two ways:
1. First, the airplane's exhaust increases the amount of moisture in the air, which can push the water content of the air past saturation point. This causes condensation to occur, and the contrail to form.
Airplane fuel such as petrol/gasoline (piston engines) or paraffin/kerosene (jet engines) consists primarily of hydrocarbons. When the fuel is burned, the carbon combines with oxygen to form carbon dioxide; the hydrogen also combines with oxygen to form water, which emerges as superheated steam in the exhaust. For every gallon of fuel burned, approximately one gallon of water is produced, in addition to the water already present as humidity in the air used to burn the fuel. At high altitudes this steam emerges into a freezing environment, (as altitude increases, the atmospheric temperature drops) which lowers the temperature of the steam until each individual droplet freezes into tiny ice crystal. These millions of tiny ice crystals form the contrails. The time the steam/water droplets take to freeze accounts for the contrail forming some way behind the aircraft's engines.
Multiple contrails in an area with high airline traffic.
2. The wings of an airplane cause a drop in air pressure in the vicinity of the wing (this is partly what allows a plane to fly). This drop in air pressure brings with it a drop in temperature, which can cause water to condense out of the air and form a contrail.
Exhaust contrails tend to be more stable and long-lasting than wing-tip contrails, which are often disrupted by the aircraft's wake and are commonly very short-lived.
Contrails and climate
Contrails, by affecting cloud formation, can act as a radiative forcing. Perhaps surprisingly, various studies find that the overall effect is a warming (Ponater et al., GRL, 32 (10): L10706 2005). However, the size of the forcing is not well known: globally (for 1992 air traffic conditions), values range from 3.5 mW/m² to 17 mW/m².
A satellite photo of Nova Scotia showing numerous contrails of jets travelling between the Eastern Seaboard and Europe.
Sept. 11th, 2001 Climate Impact "Experiment"
It had been hypothesized that in regions such as the United States with heavy air traffic, contrails affected the weather, reducing solar heating during the day and radiation of heat during the night by increasing the albedo. The suspension of air travel for three days in the United States after September 11, 2001 provided an opportunity to test this hypothesis. Measurements did in fact show that without contrails the local diurnal temperature range (difference of day and night temperatures) was about 1 degree Celsius higher than immediately before (Travis et al., J. Climate, 17, 1123-1134, 2004); however, it has also been suggested that this was due to unusually clear weather during the period (Kalkstein and Balling Jr., Climate Research, 26, 1-4, 2004).
Issue #314 -
San QuintÃn Glacier
The San QuintÃn Glacier is the largest outflow glacier of the Northern Patagonian Ice Field in southern Chile. Its terminus is a piedmont lobe just short of the Golfo de Penas on the Pacific Ocean and just north of 47°S. Like many glaciers worldwide during the twentieth century, San QuintÃn appears to be losing mass and possibly retreating. Such a change is evident in these two photographs taken by astronauts only seven years apart. The first was taken by the crew of STS-068 in October 1994 and the second by the Increment 4 crew of the International Space Station in February 2002.
Retreating San Quintin Glacier
Issue #315 -
2005 Lake Tanganyika earthquake
An earthquake along the East African Great Rift Valley faultline struck at 12:19:55 (UTC) (14:19:55 local time at the epicentre) on December 5, 2005 approximately 10 km (6 miles) below the surface of Lake Tanganyika. The estimated magnitude of the 2005 Lake Tanganyika earthquake was between 6.3 and 6.8.
Location of the 2005 Lake Tanganyika earthquake
Early reports indicated that the heaviest damage was sustained by the eastern provinces of the Democratic Republic of the Congo (DRC), a region already ravaged by extensive war and extreme poverty. The area houses tens of thousands of refugees displaced by conflicts, such as the Second Congo War and the Burundian Civil War, that have plagued the African Great Lakes for the last decade.
Two deaths have been reported so far. Dozens of houses collapsed in the DRC city of Kalemie. Michel Bonnardeaux, a UN spokesman, said that most of the casualties were caused by falling zinc or steel roofs.
Although earthquakes with magnitudes in the 6-7 range are not normally associated with massive damage, in East Africa such seismic events can wreak havoc. The quake was centred roughly below Lake Tanganyika and — in addition to the DRC, where the most widespread damage has been reported — it was felt in Burundi, Tanzania, Rwanda, and as far away as the coastal city of Mombasa in Kenya.
The tremor was felt in places as far as Luanda, Angola, where it was felt for around 20 seconds, enough to send people running in panic in search of a shelter. No damage was reported there.
Issue #316 -
Sayan Mountains
The Sayan Mountains (Russian, Sayanskiy Khrebet) is a mountain range in southern Siberia, Asia, forming the eastern continuation of the Sailughem or Altay range, stretching from 89° E to 106° E.
Sayan Mountains
Orographically they are the N border-ridge of the plateau of NW Mongolia, and separate that region from Siberia.
While the general elevation is 2,000 to 2,700 m, some of the individual peaks, consisting largely of granites and metamorphic slates, reach altitudes of over 3,000 m, with the highest being Munku-Sardyk at 3,492 m. The principal passes lie 1,800 to 2,300 m above the sea, e.g. Muztagh 2,280 m, Mongol 1,980 m, Tenghyz 2,280 m and Obo-sarym 1,860 m.
At 92°E the system is pierced by the Bel-kem or upper Yenisei, and at 106°, at its eastern extremity, it terminates above the depression of the Selenga-Orkhon Valley. From the Mongolian plateau the ascent is on the whole gentle, but from the plains of Siberia it is much steeper, despite the fact that the range is masked by a broad belt of subsidiary ranges of an Alpine character, e.g. the Usinsk, Oya, Tunka, Kitoi and Byelaya ranges.
Between the breach of the Yenisei and the Kosso-gol (lake) at 100° 30' E. the system bears also the name of Yerghik-taiga. The flora is on the whole poor, although the higher regions carry good forests of larch, pine, juniper, birch, and alder, with rhododendrons and species of Berberis and Ribes. Lichens and mosses clothe many of the boulders that are scattered over the upper slopes.
Issue #317 -
Mist
Mist is a phenomenon of a liquid in small droplets floating through air. It can occur naturally as part of natural weather or volcanic activity, and is common in cold air above hot water, in exhaled air in the cold, and in a steam room of a sauna. It can also be created artificially with aerosol canisters.
Morning mist
The only difference between mist and fog is visibility. This phenomenon is called fog if the visibility is one kilometer or less. Otherwise it is known as mist. Seen from a distance, mist is blueish, while haze is more brownish.
Strong superstitious and religious connotations are associated with mist in some cultures.
Issue #318 -
Brecon Beacons National Park
The Brecon Beacons National Park is one of three national parks in Wales, and is centred on the Brecon Beacons range of hills. The National Park was established in 1957, the last of the three Welsh parks (Snowdonia was first in 1951). Most of the national park is moorland, with some forestry plantations, and pasture in the valleys. The whole park covers 519 square miles (1,344 km²), from Llandeilo in the west to Hay-on-Wye in the east. On May 22, 2005, it was announced that the first walk to span the entire length of the Brecon Beacons National Park has opened. The 100-mile route runs from Abergavenny, through Crickhowell and ends in the village of Bethlehem in Carmarthenshire.
Brecon Beacons National Park
Popular activities in the park include walking, cycling, horse riding, sailing, windsurfing, canoeing, fishing, rock climbing, and caving. The Taff Trail passes through the Beacons on its way from Brecon to Cardiff.
The park is known for its waterfalls, including the 27-metre Henrhyd Waterfall and the falls at Ystradfellte, and its caves, such as Ogof Ffynnon Ddu.
Welsh mountain ponies may be seen grazing.
Due to its remoteness, parts of the parks are used for military training. The Special Air Service (SAS) is known for holding especially demanding and dangerous training exercises here.
Issue #319 -
Vitus Bering
Vitus Jonassen Bering (also, less correctly, Behring) (August 1681–December 19, 1741) was a Danish-born navigator in the service of the Russian Navy, a captain-komandor known among the Russian sailors as Ivan Ivanovich. He was born in the town of Horsens in Denmark and died at Bering Island, near the Kamchatka Peninsula.
Vitus Jonassen Bering
After a voyage to the East Indies, he joined the Russian Navy in 1703, serving in the Baltic Fleet during the Great Northern War. In 1710–1712 he served in the Azov Sea Fleet in Taganrog and took part in the Russo-Turkish War. He married a Russian woman, and in 1715 he made a brief visit to his hometown, never to see it again. A series of explorations of the north coast of Asia, the outcome of a far-reaching plan devised by Peter the Great, led up to Bering's first voyage to Kamchatka. In 1725, under the auspices of the Russian government, he went overland to Okhotsk, crossed to Kamchatka, and built the ship Sviatoi Gavriil (St. Gabriel). Aboard the ship, Bering pushed northward in 1728, until he could no longer observe any extension of the land to the north, or its appearance to the east.
In the following year he made an abortive search for mainland eastward, rediscovering one of the Diomede Islands (Ratmanov Island) observed earlier by Dezhnev. In the summer of 1730, Bering returned to St. Petersburg. During the long trip through Siberia along the whole Asian continent, he became very ill. Five of his children died during this trip. Bering was subsequently commissioned to a further expedition, and returned to Okhotsk in 1735. He had the local craftsmen Makar Rogachev and Andrey Kozmin build two vessels, Sviatoi Piotr (St. Peter) and Sviatoi Pavel (St. Paul), in which he sailed off and in 1740 established the settlement of Petropavlovsk in Kamchatka. From there, he led an expedition towards North America in 1741. A storm separated the ships, but Bering sighted the southern coast of Alaska, and a landing was made at Kayak Island or in the vicinity. Under the command of Aleksei Chirikov, the second ship discovered the shores of the northwestern America (Aleksander Archipelago of present-day Alaska). These voyages of Bering and Chirikov were a major part of the Russian exploration efforts in the North Pacific known today as the Great Northern Expedition.
Bering was soon forced by adverse conditions to return, and he discovered some of the Aleutian Islands on his way back. One of the sailors died and was buried on one of these islands, and the group was named after him (as the Shumagin Islands). Bering became too ill to command his ship, which was at last driven to refuge on an uninhabited island in the Commander Islands group (Komandorskiye Ostrova) in the southwest Bering Sea, where Bering himself and 28 men of his company died. This island bears his name. A storm shipwrecked Sv. Piotr, but the only surviving carpenter, S. Starodubtsev, with the help of the crew managed to build a smaller vessel out of the wreckage. The new vessel had a keel length of only 12.2 meters (40 feet) and was also named Sv. Piotr. Out of 77 men aboard Sv. Piotr, only 46 survived the hardships of the expedition which claimed its last victim just one day before coming into home port. Sv. Piotr was in service for 12 years, sailing between Kamchatka and Okhotsk until 1755. Its builder, Starodubtsev, returned home with governmental awards and later built several other seaworthy ships.
The value of Bering's work was not fully recognized for many years, but Captain Cook was able to prove Bering's accuracy as an observer. Nowadays, the Bering Strait, the Bering Sea, Bering Island, and the Bering Land Bridge bear the explorer's name.
Issue #320 -
Azuchi Castle
Azuchi Castle was one of the primary castles of Oda Nobunaga. It was built from 1576 to 1579, on the shores of Lake Biwa, in Omi Province. Nobunaga intentionally built it close enough to Kyoto that he could watch over and guard the approaches to the capital, but, being outside the city, his fortress would be immune to the fires and conflicts that occasionally consumed the capital.
Stone steps leading up to the Azuchi Castle ruins.
Unlike earlier castles and fortresses, Azuchi was not intended to be solely a military structure, cold, dark, and foreboding. Nobunaga intended it as a lavish mansion, which would impress and intimidate his rivals, not only with its defenses, but with its lavish apartments and decorations, and flourishing town and religious life. The keep, called Tenshukaku, rather than being the center of the castle's defences, was a seven-story building containing audience halls, private chambers, offices, and a treasury, as though it were a royal palace. In addition to being one of the first Japanese castles with a tower keep, Azuchi was unique in that its uppermost story was octagonal. In addition, the facade of Azuchi, unlike the solid white or black of other castles, was colorfully decorated with tigers and dragons.
There were five main militaristic features of Azuchi Castle that differentiated it from earlier castle designs. Firstly, it was a massive structure, with the walls of the castle ranging from 18 feet to 21 feet in thickness. The second feature of Azuchi Castle is the predominant use of stone. The walls were constructed from huge granite stones fitted carefully together without the use of mortar. A third innovation of the Azuchi Castle was the high central tower, or donjon. The tower allowed for increased visibility for the use of guns against an opposing force. BuilderÂ’s plans for the castle show the donjon to be 138 feet tall, with seven levels. Fourthly, Azuchi Castle had irregularly formed inner citadels. These inner citadels gave defenders ample defensive positions against intruders. The location of Azuchi Castle was also a novel feature. Whereas most Japanese castles found the most advantegous position was at the base of mountain surrounded by dense vegetation (which would allow cover for an enemy), Azuchi Castle was built on a plain to give a wide view of an approaching enemy.
Nobunaga desired a full castle town, and built well-defended homes for his generals, a Jôdo-shu Buddhist temple called Jôgon-in, and a number of homes for commoners a short distance away on the shore of the lake. However, he had trouble convincing people to move into these homes at first. In the summer of 1577, he issued a municipal charter, guaranteeing residents immunity from taxes, building or transport levies, and moratoria, and forced all travelers on the Nakasendo highway to stop in the town overnight for lodging, thus bringing business to his town's innkeepers. By 1582, the town's inhabitants numbered roughly 5,000.
In the summer of that same year, just after Nobunaga's death, the castle was attacked by the forces of Akechi Mitsuhide, Nobunaga's betrayer. The castle was set aflame, though some accounts claim this might have been the work of looting townspeople, or of one of Nobunaga's sons. Akechi, therefore, never managed to occupy the castle.
The Azuchi-Momoyama Period of Japanese history takes its name, in part, from this castle. All that remains of the castle today is the stone base. However, a reproduction of Azuchi, based on illustrations and historical descriptions, stands in Ise Sengoku Village, a samurai theme park near Ise. In addition, a full-scale replica of the top floors of the donjon is on display at the Nobunaga no Yakata Museum near the original castle ruins.
Issue #321 -
Long Island Sound
Long Island Sound is an estuary of the Atlantic Ocean and various rivers in the United States. It lies between the coast of Connecticut to the north and Long Island to the south. Many mansions along with wealthy neighborhoods characterize a good portion of the sound from the cityline of New York out to Setauket and Port Jefferson. The towns of Orient, Greenport, East Marion, Southold, and Mattituck have smaller populations are located on the extreme eastern tip of the Long Island Sound. They offer great property value as well. On the extreme western end, it is bounded on the north side by Westchester County, New York and the Bronx, and connects to the East River. On its eastern end it is connected to Block Island Sound. The sound is considered by some to be the natural border between New England and the Mid-Atlantic states.
Long Island Sound is shown highlighted in pink between Connecticut (to the north) and Long Island (to the south).
The Sound is 110 miles (177 km) long and 21 miles (34 km) wide at its widest point. It has an average depth of 78 feet (24 m), with the deepest point being 300 feet (90 m). The volume of water in the Sound is 8 trillion US gallons (30 km³). Including all islands, the Long Island Sound has a shoreline of 548 miles (882 km).
The first European to record the existence of Long Island Sound was the Dutch navigator Adriaen Block, who entered the sound from the East River in 1614.
Several major cities are situated along the Long Island Sound, resulting in a total of more than 8 million people living within its watershed. Major Connecticut cities on the Sound include Bridgeport, New London, Stamford, Norwalk, and New Haven. New York cities on the Sound include New York City (the Bronx borough).
Ferries provide service between Long Island and Connecticut, notably between Port Jefferson, New York and Bridgeport, Connecticut, and Orient Point, New York and New London, Connecticut. Some of the ferries that cross the Long Island Sound carry automobiles as well as passengers.
Underwater cables transmit electricity under the Long Island Sound, most notably the controversial Cross-Sound Cable that runs from New Haven in western Connecticut, to Brookhaven in central Long Island. Scientists debate whether or not these cables are safe for the fragile Long Island Sound environment, especially the underwater lifeforms.
The Long Island Sound side differs from the Atlantic Ocean side of Long Island because the shorelines here are rocky. The Atlantic Ocean side remains sandy with no rocks. This is due to the formation of Long Island nearly 10,000 years ago as glaciers formed the fish-shaped island.
Many attempts have been made to build a bridge over the sound, including a bridge from Rye, New York to Oyster Bay, New York, from New Haven, Connecticut to Shoreham, New York on Long Island and from Orient Point, New York to Rhode Island.
Long Island Sound has historically had a rich fishery, but in recent years the western part of the sound has become increasingly deficient of marine life. The fishing and lobstering industries have encouraged efforts to identify the cause of the dead water and rectify the problem.
Major environmental problems currently affecting the Sound include hypoxia, toxic substance and pathogen contamination, debris and other man-made pollution, and overdevelopment.
Issue #322 -
Marie Byrd Land
Marie Byrd Land is the portion of Antarctica lying east of the Ross Ice Shelf and the Ross Sea and south of the Pacific Ocean, extending eastward approximately to a line between the head of the Ross Ice Shelf and Eights Coast. The inclusion of the area between the Rockefeller Plateau and Eights Coast is based upon the leading role of Rear Admiral Richard E. Byrd in the exploration of this area. The name was originally applied by Admiral Byrd in 1929, in honor of his wife, to the northwestern part of the area, the part that was explored in that year. Due to its remotness, even by Antarctic standards, most of Marie Byrd Land has not been claimed by any sovereign nation, making it by far the largest single unclaimed territory on Earth.
Map of Antarctica showing location of Marie Byrd Land
Exploration
While the Amundsen Sea, off eastern Marie Byrd Land represented James Cook's farthest south position on his 1774 Resolution voyage, the detailed exploration of Marie Byrd Land did not begin until the United States Navy's Operation High Jump of 1946-47. Comprehensive aerial photography frrom ski equiped C-47 aircraft provided the first maps of much of Marie Byrd Land.
Occupation
Marie Byrd Land formerly hosted the Operation Deep Freeze base Byrd Station (NBY), begining in 1957. Byrd Station was the only major base in the interior of West Antarctica. In 1968, the first ice core to fully penetrate the Antarctic Ice Sheet was drilled here. The year-round station was abandoned in 1972, although many years a temporary summer encampment, Byrd Surface Camp, is opened by the USAP to support operations in northern West Antartica.
Byrd Station provided a template for the doomed Antarctic base in the horror movie John Carpenter's The Thing.
In 1998-99, a camp was operated at the Ford Ranges (FRD) in western Marie Byrd Land, supporting a part of a USAP airborne survey intiatated by UCSB and operated by the University of Texas Institute for Geophysics.
In 2004-05, a large camp, Thwaites (THW) was established by the USAP 150 km north of NBY, in order to support a large airborne geophysical survey of eastern Marie Byrd Land by the University of Texas Institute for Geophysics.
In 2006, a major encampment, WAIS Divide (WSD) was established on the divide between the Ross Sea Embayment and the Amundsen Sea Embayment, in easternmost Marie Byrd Land, in order to drill a high resolution ice core over the following three years.
Issue #323 -
Ellesmere Island
llesmere Island, in the Arctic Ocean, is the world's 10th largest island, and Canada's third largest island, with an area of 196,235 km² (75,767 square miles). Ellesmere Island (French: île d'Ellesmere) is part of the Arctic Islands of the Canadian territory of Nunavut. In 2001 it had a population of 168.
Ellesmere Island, Nunavut
The island was first sighted by William Baffin (c. 1584–1622) in 1616. It was named in 1852 by Sir Edward A. Inglefield's expedition after Francis Egerton, 1st Earl of Ellesmere.
More than one-fifth of the island is protected as Quttinirpaaq National Park, which includes seven fjords and a variety of glaciers. Barbeau Peak, the highest mountain in Nunavut (2,616 m) is located in the British Empire Range on Ellesmere Island. The most northern mountain range in the world, the United States Range is located in the northeast region of the island. The northern lobe of the island is called Grant Land.
Large portions (80,000 km²) of Ellesmere Island are covered with glaciers and ice, with Manson Icefield and Sydkap in the south; Prince of Wales Icefield and Agassiz Ice Cap along the central-east side of the island, along with substantial ice cover in Northern Ellesmere Island. Along the northwest coast of Ellesmere Island are some ice shelves, including the Ward Hunt ice shelf which experienced major breakup during summer 2002.
A satellite image of the northern segment of Ellesmere Island, Nunavut. Greenland is to the east.
There are three settlements on Ellesmere Island: Alert, Eureka, and Grise Fiord. Politically, it is part of the Baffin Region.
Canadian Forces Station (CFS) Alert is the northernmost settlement in the world. With the end of the Cold War and the advent of new technologies allowing for remote interpretation of data, the overwintering population has been reduced to 50.
Eureka, which is the second nothernmost settlement in the world, consists of three areas, the "airport" which includes "Fort Eureka" (the quarters for military personnel maintaining the island's communications equipment), the Environment Canada Weather Station and the ASTRO Observatory.
Issue #324 -
Inga Dam
The Inga Dam is a dam on the Inga Falls in the Congo where the Congo River drops 100 metres.
Inga Dam
Currently, two dams Inga I and Inga II, are inactive, but the World Bank, among other groups, is contemplating investing as much as 500 million dollars into rehabilitating them. Also, a plan for Inga III, a massive hydroelectric station, the construction of which would cost approximately 6 billion dollars, is currently being discussed. Projections indicate that Inga III would generate 39,000 megawatts of electricity- enough to satisfy the energy needs for the entire African continent.
The existing dams are famous white elephants of former Président Mobutu Sese Seko.
Issue #325 -
Bangweulu Wetlands
The Bangweulu Wetlands or Bangweulu Swamp lies in northern Zambia, east of Lake Bangweulu, around the Luapula River and its tributaries. Grassy floodplains lie south of the wetlands, acting as an extension of the region in the wet season.
Bangweulu Wetlands
The wetlands are known for wildlife including the near-endemic black lechwe, various other antelopes, elephants, buffalo, pelicans, spoonbills, flamingos and many other birds.
The wetlands are known for being one of the few breeding grounds of the Shoebill, a large stork-related bird that nests on the ground. The Bangweulu Swamp wetland reserve is of particularly importance as the Shoebill is classified as an endangered species (near threatened) and only has about 2 offspring maximum per year.
Issue #326 -
Mather Gorge
Mather Gorge is a river gorge south and just downriver of Great Falls on the border of Maryland and Virginia. The Maryland side of the gorge is part of the Chesapeake and Ohio Canal National Historical Park and the Virginia side is part of Great Falls Park. Both parks are National Park Service sites. The gorge is named after Stephen Tyng Mather, the first director of the National Park Service.
Mather Gorge
The gorge is cut by the Potomac River and is, for the most part, lined on both sides by cliffs. Towards the southern end of the gorge, the cliffs become tree-lined bluffs. After the narrow gorge the river widens (crossing the fall line) as it leaves the piedmont and enters the coastal plain.
Hiking is a common activity with many trails along and near the gorge. On the Maryland side, in the C&O Canal National Historical Park, Section A of the Billy Goat Trail follows the gorge. The River Trail in Great Falls Park follows the gorge on the Virginia side. The river itself is a whitewater attraction. It is also a popular rock climbing attraction as the cliff heights and terrain lend themselves well to top rope climbing.
Issue #327 -
Mani Peninsula
The Mani Peninsula, also known as Maina, is a region in Greece. The Mani is the central peninsula of the three which extend southwards from the Peloponnese in southern Greece. To the east is the Laconian Gulf, to the west the Messenian Gulf. The peninsula forms a continuation of the Taygetos mountain range, the western spine of the Peloponnese.
Mani Peninsula
The terrain is mountainous and inaccessible. The name "Mani" is thought to have originally meant "dry" or "treeless." Until recent years many Mani villages could be reached only by sea. Today a narrow and winding road extends down the west coast from Kalamata to Areopoli, but on the east coast there is no substantial road south of Gytheio.
Administratively, The Mani is divided between the districts of Laconia and Messenia, in the province of Peloponnesos, but in ancient times it lay entirely within Laconia, the district dominated by Sparta. The Messenian Mani receives somewhat more rainfall than the Laconian, and is consequently more fertile. Messenian Maniot surnames almost uniformly end in -eas, whereas Laconian Maniot ones in -akos.
Neolithic remains have been found in the many caves along the Mani coasts. Homer refers to a number of towns in the Mani region, and some artifacts from the Mycenean period have been found. The area was occupied by the Dorians in about 1200 BC, and became a dependency of Sparta. When Spartan power was destroyed in the 3rd century, the Mani was self-governing for a time before being absorbed into the Roman Empire in the 2nd century.
The coastline of the Mani Peninsula
As the power of the Byzantine Empire declined in the 9th century AD, the peninsula drifted out of the Empire's control. The fortress of Maini in the south became the area's centre. Over the subsequent centuries the peninsula was fought over by the Byzantines, the Franks and the Saracens.
After the fall of Constantinople to the Fourth Crusade in 1204, Italian and French knights (known to the Greeks as Franks), occupied parts of the Peloponnese. In 1249 the Mani was occupied by the Venetians, who made it one of the twelve baronies of the Principality of Moreas and built the fortresses of Mystras, Passavas, Gustema (Beaufort) and Megali Maini.
In 1460 Mystras fell to the Ottomans, but the Mani was not subdued and retained its internal self-government in exchange for an annual tribute. Local chieftains or beys governed Mani on behalf of the Ottomans. As Ottoman power declined, the mountains of the Mani became a stronghold of the kleftes, bandits who also fought against the Ottomans. There is evidence of a sizeable Maniot emigration to Corsica sometime during the Ottoman years.
The last bey of Mani, Petros Mavromichalis was among the leaders of the Greek War of Independence. He proclaimed the revolution at Areopoli on March 17, 1821. The Maniots contributed greatly to the struggle, but once Greek independence was won they wanted to retain their local autonomy. During the reign of Ioannis Kapodistrias they violently resisted outside interference.
The Mani's local autonomy was abolished in 1870, and the area gradually became a backwater as the inhabitants abandoned the land through emigration. It was not until the 1970s, when new roads led to the growth of the tourist industry, that the Mani began to regain population and become prosperous. Maniots were known for their obstinate character, conservative views, sometimes extreme frugality, and their zealous safeguarding of the family property.
Despite the region's aridity, Mani is known for unique culinary products such as glina or syglino (pork or pork sausage smoked with aromatic herbs such as thyme, oregano, mint, etc. and stored in lard along with orange peel), and what is probably the world's best extra-virgin olive oil, soft-pressed from partially ripened olives of the Koroneiki varietal that are organically grown on mountain terraces.
Today the Mani's coastal villages are full of cafes and souvenir shops. The peninsula attracts visitors for its Byzantine churches, Frankish castles and stunning scenery. Furthermore, the famous towers of Mani are significant tourist attractions. Gytheio, Areopoli, Kardamyli and Stoupa are filled with German and other tourists during the summer months.
Issue #328 -
Dacite
Dacite is a high-silica igneous, volcanic rock. It is intermediate in compostion between andesite and rhyolite, and, like andesite, it consists mostly of plagioclase feldspar with biotite, hornblende, augite or enstatite. It has an aphanitic to porphyritic texture with quartz as rounded, corroded phenocrysts, or as an element of the ground-mass.
Gray, red, black, altered white/tan, flow-banded pumice dacite
The feldspar content ranges from oligoclase to andesite and labradorite, and is often very zoned. Sanidine occurs also in some dacites, and when abundant gives rise to rocks that form transitions to the rhyolites. The biotite is brown; the hornblende brown or greenish brown; and the augite is usually green.
The ground-mass of these rocks is often microcrystalline, with a web of minute feldspars mixed with interstitial grains of quartz; but in many dacites it is largely vitreous, while in others it is felsitic or cryptocrystalline. In the hand specimen many of the hornblende and biotite dacites are grey or pale brown and yellow rocks with white feldspars, and black crystals of biotite and hornblende. Other dacites, especially augite- and enstatite-dacites, are darker colored.
The rocks of this group occur in Romania, Almeria (Spain), Argyll and other parts of Scotland, New Zealand, the Andes, Martinique, Nevada and other districts of western North America, Greece as well as other places. They are mostly associated with andesites and trachytes, and form lava flows, dikes, and in some cases form massive intrusions in the centers of volcanoes.
The word dacite comes from Dacia, a Roman province found between the Danube River and Carpathian Mountains (nowadays modern Romania) where the rock was first described.
Issue #329 -
Flakfortet
Flakfortet is a sea fortress located on the artificially built island, Saltholmreb, in Øresund between Copenhagen and Malmö. The Island and Fort are simple known as Flakfortet, the name of the Island, Saltholmreb, is seldom used.
Flakfortet
The Fort was built in the years 1910 - 1915 as part of Copenhagen's sea-fortifications. Until 2001 the Fort (and Island) was owned by the Danish Ministry of Defence, who had not used it actively since 1968. It was put up for sale in 1999 under the guidance of Statens Ejendomssalg (commonly known as Freja) which is the department under the Danish Ministry of Finance responsible for selling state-owned property that is not used by the State anymore.
In June 2001 it was sold to the Swedish company Malmökranen, however since the Fort is a Danish designated protected area the new owners must maintain the area and make it public available. The sale also had to be approved by the Danish Skov- og Naturstyrelsen who is the organization responsible for such areas in Denmark.
Issue #330 -
Kathiarbar-Gir dry deciduous forests
The Kathiawar-Gir dry deciduous forests are a tropical dry broadleaf forest ecoregion of western India.
Ranthambore Tiger Reserve, India
Setting
The Kathiawar-Gir forests have a disjunct distribution. The main part of the ecoregion comprises the Aravalli Range and the eastern half of Rajasthan state, extending into eastern Gujarat and the Malwa region of Madhya Pradesh. A small enclave of the ecoregion covers the peak of Girnar on the Kathiawar peninsula of western Gujarat. The drier Northwestern thorn scrub forests ecoregion lies to the west, covering the remainder of the Kathiawar Peninsula and the strip of western Rajasthan between the Aravalli Range and the Thar Desert. To the northwest the Kathiawar-Gir dry deciduous forests transition to the Upper Gangetic Plains moist deciduous forests. To the southeast lies the Narmada Valley dry deciduous forests ecoregion, which covers the Vindhya Range and Narmada River valley. The ecoregion also borders on the North Western Ghats moist deciduous forests in southeastern Gujarat.
The ecoregion has tropical monsoon climate, with most of the rainfall during the southwest monsoon (June-September), and arid for the remaining months of the year. Rainfall averages 550 to 700 mm/year. Temperatures often exceed 40 ºC. Higher elevations of the Aravallis stay cooler, and the windward slopes (generally southeast-facing) receive higher rainfall.
Flora
The composition of the ecoregion's forests varies with moisture and soils. Wetter areas are home to three-storied forests dominated by teak (Tectona grandis) in association with Agele marmelos, Boswellia serrata, Ougeinia oojeinensis, Diospyros spp., Bombax ceiba, Sterculia urens, Emblica officinalis, Dalbergia paniculata, and Terminalia tomentosa. These forests have a three-storied structure, with the top story reaching from 15 to 25 meters. Anogeissus pendula, growing in almost pure stands or in association with Acacia catechu is predominant in drier areas, especially on the quartzite ridges and gneiss hillocks of the Aravalli Range. Thorn scrub forests, characterized by Euphorbia caducifolia, Maytenus emarginata, Acacia senegal, Commiphora mukul, Wrightia tinctoria, Securinega leucopyrus, Grewia tenax, and Grewia villosa, occur on rocky hillsides and in degraded areas. The highest elevations of Mount Abu are covered with conifer forests.
Fauna
Top predators include the Asiatic Lion (Panthera leo persica), Bengal Tiger (Panthera tigris tigris) Leopard (Panthera pardus), and Indian Wolf (canis lupus pallipes). Other mammal fauna include the Hyena (Hyena hyena), Chousingha (Tetracerus quadricornis), Blackbuck, (Antilope cervicapra), and Chinkara (Gazella bennettii). Bird species include the endangered Indian Bustard (Ardeotis nigriceps), and Lesser Florican (Eupodotis indica), and the near-endemic White-naped tit.
Conservation
Reserves in the ecoregion include Gir National Park in Gujarat, which is only remaining habitat of the Asiatic Lion; Ranthambore National Park and Sariska National Park, which are important Project Tiger sanctuaries; and the wildlife sanctuaries at Jaisamand, Kumbhalgarh, and Mount Abu.
Issue #331 -
El Tatio
El Tatio Geyser Field (locally known as Los Géiseres del Tatio) is located within the Andes Mountains of northern Chile at 4,200 meters above mean sea level.
Geyser of El-Tatio
Contrary to some reports, it is not the highest-elevation geyser field in the world. Puchuldiza Geyser Field, Chile, and possibly several other fields are higher in elevation. Tourists often visit the geysers while touring the nearby Atacama Desert and the village San Pedro de Atacama. With over 80 active geysers, El Tatio is the largest geyser field in the southern hemisphere and the third largest field in the world, after Yellowstone, USA, and Dolina Giezerov, Russia.
Though possessing numerous geysers, none erupt very high. The highest eruption observed has been around six meters in height. The average geyser eruption height at El Tatio is about 75 centimeters.
"El Tatio" roughly translates to "the grandfather".
Issue #332 -
Oslo Graben
The Oslo Graben or Oslo Rift is a graben formed during a geologic rifting event in Permian time. The rift formation was accompanied by volcanic activity and associated rhomb porphyry lava flows. It is located in the area around the Norwegian capital Oslo.
LANDSAT image of southern Norway. Red line = Caledonian front, Yellow line = MANUS, Purple line = Porsgrunn-Kristiansand fault, Blue lines = Oslo graben.
The lava production was high when the rhomb porphyry lavas were deposited. The lavas reflect a period of abundant earthquake-related movements, when strong forces tore the crust apart.
In the Vestfold district, one lava flow was deposited on average every 250,000 years. Here occurs a 3,000 metre thick sequence of mainly volcanic material. In the Oslo area, lavas were deposited on average every 800,000 years. Only a few plant remains have been found between these lavas.
Issue #333 -
Kara Sea
The Kara Sea is part of the Arctic Ocean north of Siberia. It is separated from the Barents Sea to the west by the Kara Strait and Novaya Zemlya, and the Laptev Sea to the east by the Severnaya Zemlya.
A map showing the location of the Kara Sea.
It is roughly 1,450 kilometres long and 970 kilometres wide with an area of around 880,000 km² and a mean depth of 110 m.
The Kara receives a large amount of fresh water from the Ob, Yenisei, Pyasina, and Taimyra rivers, so its salinity is very variable.
Its main ports are Novyy Port and Dikson and it is important as a fishing ground although the sea is ice-bound for all but two months of the year. There is the possibility of significant reserves of petroleum or natural gas beneath the sea, but this has yet to be confirmed (2001).
There is concern about the levels of nuclear waste the former Soviet Union dumped in the sea which included six nuclear submarine reactors and ten nuclear reactors, and the effect this will have on the marine environment. An International Atomic Energy Agency appraisal showed that releases are low and localised.
Issue #334 -
Chalcopyrite
Chalcopyrite is a copper iron sulfide mineral that crystallizes in the tetragonal system. It has the chemical composition CuFeS2. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Due to its color and high copper content, chalcopyrite has often been referred to as "yellow copper".
Chalcopyrite
Chalcopyrite is often confused with pyrite, although the latter has a cubic and not a tetragonal crystal system. Further, chalcopyrite is more often massive and less brittle. Chalcopyrite is also a darker yellow in color.
Chalcopyrite is one of the most important copper ores. Chalcopyrite ore occurs in a variety of ore types, from huge masses as at Timmins, Ontario, to irregular veins and disseminations associated with granitic to dioritic intrusives as in the porphyry copper deposits of Broken Hill, the American cordillera and the Andes.
Issue #335 -
Empty Quarter
The Empty Quarter (Arabic: Rub' al Khali), is the largest sand desert in the world, encompassing the southern third of the Arabian Peninsula, including southern Saudi Arabia, and areas of Oman, the United Arab Emirates and Yemen.
Sand dunes in the Empty Quarter
Still largely unexplored, and virtually uninhabited, the desert is a thousand kilometers (600 miles) long, and 500 km (300 mi) wide. Even the Bedouins only skirt the edges of the desert. Nonetheless, tour companies do exist that offer GPS-equipped excursions into the desert. The first documented journeys made by Westerners to the Empty Quarter were those made by Bertram Thomas in 1931 and St. John Philby in 1932.
With summer temperatures ranging from below freezing at night to over 60 degrees Celsius (140 F) at noon, and dunes taller than the Eiffel Tower - over 330 meters (1,000 ft) - the desert may be the most forbidding environment on Earth. However, as nearly everwhere else, life flourishes. Arachnids, rodents and plant life can all be found throughout the Empty Quarter. As an ecoregion, it falls within the Arabian Desert and East Sahero-Arabian xeric shrublands.
Desertification has increased through the millennia. Before desertification made the caravan trails leading across the Rub' al Khali so difficult, the caravans of the frankincense trade crossed now virtually impassable stretches of wasteland, until about 300 AD. An example is the lost city of Ubar, which depended on such trade.
Geologically, the Empty Quarter is one of the most oil-rich places in the world. Vast oil reserves have been discovered underneath the sand stacks. Sheyba, in the middle of the desert, is a major Arab light crude oil-producing site in Saudi Arabia. Also, Ghawwar Field, the largest oil field in the world, extends southward into the northernmost parts of the Empty Quarter.
Issue #336 -
Chicago Sanitary and Ship Canal
The Chicago Sanitary and Ship Canal is the only shipping link between the Great Lakes (specifically Lake Michigan by the Chicago River) with the Mississippi River system, by way of the Illinois and Des Plaines rivers. The canal also carries Chicago's treated sewage into the Des Plaines River. Before completion of the canal in 1900, the sewage of Chicago was dumped into Lake Michigan, the city's drinking water supply. The canal is part of the Chicago Wastewater System, operated by the Metropolitan Water Reclamation District of Greater Chicago. The system has been named a Civil Engineering Monument of the Millennium by the American Society of Civil Engineers (ASCE). The Chicago Sanitary and Ship Canal is 30 miles (48 kilometers) long, 202 feet (62 meters) wide, and 24 feet (7.3 meters) deep. Prior to its building, the Illinois and Michigan Canal connected the same waterways for boat travel.
Chicago Sanitary and Ship Canal (at the time named the Chicago Drainage Canal) being built
Early Chicago sewage systems discharged directly into Lake Michigan or into the Chicago River, which itself flowed into the lake. The cityÂ’s water supply also came from the lake, through water intake cribs located offshore. Inevitably, sewage infiltrated the water supply, leading to typhoid fever, cholera and dysentery. A cholera epidemic in 1854 killed more than 5 percent of the cityÂ’s population. Deaths from typhoid fever averaged 65 per 100,000 population a year between 1860 and 1900. The water cribs were moved farther out into the lake, but this effort did not stem the epidemics.
By 1887, it was decided to reverse the flow of the Chicago River through civil engineering. Engineer Rudolph Hering noted that a ridge about 12 miles from the lake shore divided the Mississippi River drainage system from the Great Lakes drainage system. A plan soon emerged to cut through that ridge and carry waste water away from the lake, through the Des Plaines and Illinois rivers, to the Mississippi River and the Gulf of Mexico. In 1889, the Illinois General Assembly created the Metropolitan Sanitary District of Greater Chicago (now the Metropolitan Water Reclamation District of Greater Chicago) to carry out the plan.
The canal, linking the south branch of the Chicago River to the Des Plaines River at Lockport, was completed in 1900. The rate of flow is controlled by the Lockport Powerhouse, sluice gates at Chicago Harbor and at the O'Brien Lock in the Calumet River, and also by pumps at Wilmette Harbor. Two more canals were later built to add to the system: The North Shore Channel in 1910, and the Calumet Sag Channel in 1922.
Construction of the Ship and Sanitary Canal was the largest earth-moving operation that had been undertaken in North America up to that time. It was also notable for training a generation of engineers, many of whom later worked on the Panama Canal.
Water diversions from the Great Lakes system are now regulated by an international treaty with Canada and by governors of the Great Lakes states.
It is also worth noting that that Standards of the Tubular Exchangers Manufacturers' Association (TEMA) once listed a fouling factor of 0.008, but recent editions have omitted this as no heat exchangers take cooling water from the canal.
Issue #337 -
Lithosphere
The lithosphere (from the Greek for "rocky" sphere) is the solid outermost shell of a rocky planet. On the Earth, the lithosphere includes the crust and the uppermost layer of the mantle (the upper mantle or lower lithosphere) which is joined to the crust. The lithosphere is broken up into different tectonic plates.
The tectonic plates of the Lithosphere on Earth.
The distinguishing characteristic of the lithosphere is not composition, but its flow properties. Under the influence of the low-intensity, long-term stresses that drive plate tectonic motions, the lithosphere responds essentially as a rigid shell and thus deforms primarily through brittle failure, while the asthenosphere accommodates strain through plastic deformation. Both the crust and upper mantle float on the more plastic asthenosphere. The crust is distinguished from the mantle, and hence the upper mantle, by the change in chemical composition that takes place at the Moho discontinuity. The thickness of the lithosphere varies from around 1.6 km (1 mi) at the mid-ocean ridges to approximately 130 km (80 mi) beneath older oceanic crust. The thickness of the continental lithospheric plates is probably around 150 kilometers (93 mi).
As the cooling surface layer of the Earth's convection system, the lithosphere thickens over time. It is fragmented into relatively strong pieces, called tectonic plates, which move independently relative to one another. This movement of lithospheric plates is described as plate tectonics. There are two types of lithosphere:
* oceanic lithosphere
* continental lithosphere
Other planets
Some planets, such as Mercury, appear to be just lumps of rock, with no apparent magma underneath any kind of crust. Other planets such as Mars have a thicker lithosphere than ours with far less (if any) plate movement. A thicker lithosphere can support heavier features such as volcanos. This combined with less plate movement results in volcanos staying over the same hotspot for far longer than they would here, results in volcanos that dwarf in size those on Earth.
Issue #338
