Saturday, July 17, 2010

Jeita Grotto – Lebanon

The Jeita Gratto is a compound two separate but interconnected karstic limestone caves spanning of nearly 9 kilometeres. The caves are situated in the Nahr al –Kalb valley within locality of Jeita, 18 kilometers nort of the Lebanese capital Beitrut. Though inhabited in prehistoric times, the lower cave was not rediscovered until 1836 by William Thomson, it can only be visited by boat since it channels an underground river that provides fresh drinking water more than million Lebanese.

World’s largest stalactite

In 1958, Lebanese Speleologist discovered the upper galleries 60 meters (200 ft) above the lower cave which have been accommodated with an access tunnel and a series of walkways to enable tourist safe access without disrobing the natural landscape. The upper galleries house the world’s largest stalactite, they are composed of series of chambers the the largest of which peaks at a height of 120 meters (390 ft).
Aside from being a Lebanese national symbol and top tourist destination, Jeita Grotto plays an important social, economic and cultural role and is a finalist in the New 7 wonders of Nature competition. Jeita Grotto is a set of interconnected limestone caves located in Lebanon. A river runs through the two caves referred to as the lower cave and the upper galleries. The Jeita Grotto is the longest cave complex in the Middle East with a height difference of 305 meters (1,000 feet). The Jeita Grotto sits at 300 meters (980 feet) above sea level. Explorers have made their way 6,910 meters (22,700 feet ) from the front entry way of the lower grotto to the deepest end of the underground river. And about 2,130 meters (7,000 feet ) of the upper galleries.
The name of the cave changed several times since its discovery. Initially referred to as the Grottoes of Nahr al-Kalb, it was subsequently known as Djaita, Jehita and finally Jeita. Naher el Kalb is the name of the river that runs through the grottoes, while Jeita, meaning “roaring water” in Aramaic, is the town in which the cave’s entrance is located. The transition from Gottoes of Nahar al-Kalb to Jeita Grottoes occurred in 1927 as newspapers widely used the latter name. In 1961, Jeita became a national symbol when Lebanse authorities issued a stamp featuring the lower cavern to promate national tourisum.

Geology

The Jeita grotto is located within the Lower_Middle Jurassic strata of Keserouane which has a stratigrapic thickness of 1,000 meters (3,300 feet) and consist of dolostone and micritic limestone. The Keserouane formation was exposed to air by a local uplift during the Late Jurassic-Early Cretaceous. The Keserouane strata became karstified after its aerial exposure and then was buried during the Cretaceous. In the Neogene, upon the final uplift of Mount Lebanon, this early karstification phase was reactivated.

Friday, July 16, 2010

Aldabra Atoll - Ideal Natural Laboratory



The Aldabra atoll comprise four large coral island which enclose a sallow lagoon;the group of island is itself surrounded by a coral reef. Due to difficulties of access and the atoll’s isolation, Aldabra has been protected from human infuluance and thus retains some 152,000 giant tortoises, the world’s largest population of reptile.
Aldabra Atoll (924’ S, 4620’ E) is a large (34 Km long, maximum 14.5 km wide , area 155 km2 ) raised atoll located in the Western Indian Ocean. It is situated 1150 km southwest of Victoria ( the capital of the Seychelles on the island of Mahe ) and 420 km north of Madagascar. Aldabra has been described as “One of the Wonders of the world” by Sir David Attenborough a isolation in a remote area of the Indian Ocean, combined with an inhospitable terrestrial environment, has helped preserve in a relatively natural state.
Increasing level of stress from human activities are contributing to the decline of the world’s coral reefs, Aldabra has so far escaped the worst of these stresses and provides an ideal natural laboratory for studying tropical marine ecosystems and related environments (Such as Sea grass and mangroves)

THE LIMESTONE

Aldabra if formed from late Quaternary raised reef limestone, averaging 2 km in width and up to 8m above sea level, and rimming a shallow central lagoon. The limestone has been eroded over the years to from a dangerous terrain of sharp spiky rocks and numerous pits, making walking off established tracks unadvisable.
Many of the pits contain fresh or brackish water that sits on top of surrounding seawater as a lense and rises and falls with tides. Aldabra has monthly mean maximum (December) and minimum (August) temperatures of 31C and 22C respectively. Average rainfall, with Aldabra located relatively dry zone of the southwest Indian Ocean, is 1100mm per year. Climate is heavily influenced by the NW monsoon winds from November to March bringing the heaviest rainfall, with SE trades blowing throughout the remainder of the year. The lagoon At Aldabra is linked to the ocean by two major and smaller channels and by several smaller reef passages. Tidal range is 2 to 3 m and results in large exchange of water between the lagoon and open ocean through the channels. The main cannel alone drains approximately 60% of the lagoon.
The scientific history of Aldabra encompasses almost 100 years of the both terrestrial and marine based investigations. Early contributions regarding the flora and fauna, and indeed geomorphological structure, of Aldabra made it in 1910 one of the better known Indian Ocean reef island. In the mid 1960s Aldabra was thrust into the international spotlight, being considered by the British Government as a possible air-staging outpost, with the threat of the construction of an airstrip and support facility.

PHYSICAL FEATURES

Aldabra is classic coral atoll, 34 km long by maximum of 14.5 km wide, which has been built up from a seabed. It comprises four main islands of coral limestone separated by narrow passes and encloses a large shallow lagoon. Most of the land surface comprises ancient coral reef (about 125,000 years old) now raised above sea level, the rest being even older reef limestones. The lagoon, which covers some 14,000 ha, contains many smaller islands and the entire atoll is surrounded by an outer reef. Geomorphological processes have produced a varied and generally rugged topography. Weathering has eroded the limestone into hole and pits over much of the surface of the island, although the surface at the eastern end comprises raised lagoonal sediments. The limestone cliffs along the cost are undercut, and there is a perched beach and sand dunes on the southern (windward) cost. Tidal range is more than 3 m which can lead to strong channel currents.

CLIMATE

Tropical with an average annual temperature of 27 C. Average rainfall is about 1,200 mm, although the annual rainfall varies greatly between years. There is a pronounced wet season from November to April drier season from May to November. The area is occasionally affected by cyclones.

VEGETATION

The terrestrial flora includes some 178 species of indigenous flowering plants, of which about 20% are thought to be endemic. Many of these plants are considered to be threatened. Mangrove Swamp grows around the edge of the lagoon and inshore water support sea-grass meadows. Much of the fretted limestone terrain is covered with dense Pemphis acidulla thicket. On the flat limestone, there is a mixed growth of low trees, shrubs and grasses. On the west coast, there are few limited areas where coconut groves have been palnted.

FAUNA

This island group is one of the few areas in the world where reptiles dominate the terrestrial Fauna, with the largest world population (152,000) of giant tortoise Geochelone gigintea, which arrears to be self-sustaining. Green turtle Chelonia mydas and Hawksbill turtle Eretmocheyls imbricate breed here. There 13 species of terrestrial birds including the last representative of the wetern Indian Ocean flightless birds- the endemic Aldabran white-throated rail Dryolimnas cuvieri aldabranus (about 5,000 individuals). Aldabran drongo Dicrurus aldabranus (approximately 1,500 individuals) is also endemic species which inhabits scrub, mangrove and casuarinas areas. Aldabra warbler Nesillas aldabranus has not been seen for several years and might be naturally extinct.
Previously restricted to 10 ha of costal tall scrub, This was considered possible the most endangered bird in the world, as only five birds have been seen since its discovery in 1968.Aldabra is the main breeding site in the Indian Ocean for red-tailed tropic bird Phaethon rubricauda, red-footed boody sula sula, greater frigatebird Fregata minor and lasser frigatebird F. ariel. There are also large numbers of white-tailed tropic bird P. lepturus, masked boody sula dactylatra, Abbott’s boody s. leucogaster.

Hopewell Rocks - Canada



Hopewell Rocks are one of Canada’s natural wonders located in the upper end of the Bay of Fundy, New Brunswick-which is itself a natural wonder with the world’s highest tides.
The Hopewell Rocks, also called the Flowerpot Rocks or simply The Rocks, are rock formations caused by tidal erosion in The Rocks Provincial Park in New Brunswick.
They are located on the shores of the upper reaches of the Bay of Fundy at Hopewell Cape near Moncton, New Brunswick. Due to the extreme tidal range of the Bay of Fundy, the bases of the formations are covered in water twice a day. However, it is possible to view the formations from ground level at low tide.
The formations consist of dark sedimentary conglomerate and sandstone rock. The large volume of water flowing in to and out of the Bay of Fundy modifies the landscape surrounding it. After the of the glaciers in the region following the last ice age, surface water filtering through cracks in the cliff has eroded and separated the formations from the rest of the cliff face.
Meanwhile, advancing and retreating tides and the associated waves have eroded the base of the rocks at a faster rate than the topes, resulting in their unusual shapes. The vast sediment planes in the basin in Fundy support a variety of biological productivity. Various shorebirds are often seen flocking to nest and feed in the area.
Visitors are advised to stay for a full tidal cycle to get a full appreciation of the tides and formations. Although the tides vary from day to day the high tide can be as high as r6 feet (14 meters) giving The Hopewell Rocks the world record for the highest average tides in the world.

Mount Kilimanjaro - Kenya



Mount Kilimanjaro was formed during the most recent faultingof the Rift valley two to three million years ago, an event that also led to the formation of Mount Kenya. Kilimanjaro was certainly an active volcano 100,000 years ago when the crater below
kibo Peak was formed. The glaciers around the peak probably began to form some 11,700 years ago.
However, it is thought that due to global warming they will have melted within another 20 years. It is possible that the snow-capped Mountains of the Moon described the Greek geographer, Ptolemn, in the second century AD referred to Mount Kilimanjaro. In the sixth century Chinese sailors returned home with tales of a great inland mountain, but Kilimanjaro remained something of an enigmatic legend to non-Africans well into the nineteenth century.
In 1848, the German missionar, Johannes Rebmann, while venturing inland in a bid to convert the tribes to Christianity, sighted th snow-capped mountain from Tsavo but his report was met with redicule until 1861 whn Dr Otto Kersten and Baron Karl Klasu vonder Decken scaled the mountain to height of 4300 meters.
The first Eurpoenans to reach summit were Hans Meyer and Ludwig Purtschelloer in 1889.
Mawenzi peak was first climbed in 1912.
The mountain has retained a legendary and almost mystical aura throughout the twentieth century. In 1938 Ernest Hemingway enhanced this when he wrote his classic nowel, te Snows of Kilimanjaro. On 1st January 2000, a thousand people watched the first sunrise of the new millennium from the peak.

Igussu Falls – Between Argentine & Brizil



Spectacular, breathtaking, majestic. There’s no better description of the torrents of water cascading down Isuassu Falls, one of the largest and most impressive falls in the world. The name Iiguassu comes from the Guaranani Indian word meaning “great water”.
The waterfall system consists of 275 falls along 2.7 kilometers (1.67 miles) of the Iiguazu River. Position is at Jatitude (DMS): 25 40’ 60 S longitude (DMS) 54” 25’ 60 W. Some of the individual falls are up to 82 meters (269 ft) in height, though the majority are about 64 meters (210 ft).
The Devil’s Throat (Garganta del Diablo in Spanish or Garganta do Diabo in Portuguese), a U-shaped, 82 meter-high, 150 meter-wide and 700-meter-long 460 by 2300 feet) cataract, is the most impressive of all, and marks the border between Argentian and Brazil. Two thirds of the falls are within Argentine territory. About 900 meters of the 2.7 kilometer length does not have water flowing over it.
The edge of the basalt cap recedes only 3 mm (0.1 in) per year. The water of the lower Iguazu collects in a canyon that drains in the Parana River at argentian, shortly downstream from the Itaipu dam.

Havasu Falls – United States



Havasu Falls is paradise on Earth. This is an absolutely amazingly beautiful waterfall located in remote canyon of Arizona. It takes a good deal of effort to get there, but the reward is worth it. If you go to Havasu Falls, you will no doubt think you are somewhere in Hawaii. It is an oasis in arid Arizona.
The Havasu Baaja (the-people-of-the-blue-green-waters) or more commonly the Havasupai, are a native American tribe that has called the Grand Canyon its home for at least the past 800 years. Located primarily in an area known as Cataract Canyo, this Yuman speaking population once laid claim to land reservation the size of Delaware. In 1882, however, the tribe was forced by the federal government to abandon all but 518 area of their land.
The Havasupai witnessed at silver rush and the Santa Fe Railroad in effect destroy what was fertile land. Furthermore,the inception of the Grand Canyon as a National Park in 1919 pushed the Huvasupi to the brink as their land was consistently being unlawfully entered and misused by the National Park service. Over the next century the tribe used the United States judicial system as a means of fighting for restoration of the land which had been unceremoniously taken from them.
In 1975 , after years without progress, the tribe succeeded in regaining 251,000 acres of their ancestors land with the passage of Congressional bill S. 1296.
Besides their battle on Capitol Hill, the Havasupai are well known for the area in which they reside. As a means of surviving and flourishing in the modern economy the tribe has turned its land, which consists of richly colored waters and its awe-inspiring waterfalls, into a bustling tourist hub that attracts thousands of people every year