Snipfact:

  The Great Lakes are a group of five freshwater lakes in North America on the border between the USA and Canada. Superior is so called because it is higher upstream that the others. Huron takes its name from the name French settlers gave to a local Indian tribe (from hure, a boar’s head). No one knows where the name Michigan comes from, but Erie and Ontario are both from the Iroquois language. Erie means cat, the animal the tribe used as its symbol. Ontario simply means beautiful lake. 1 Superior, Canada/USA –82,414 sq km 2 Huron, Canada/USA –59,596 sq km 3 Michigan, USA –58,016 sq km 4 Erie, Canada/USA –25,719 sq km 5 Ontario, Canada/USA –19,477 sq km

  Waterfalls form when a river or stream goes over a drop, often where softer rocks are eroded faster than harder ones. The drop is the distance from top to bottom of the waterfall. 1 Angel Falls, Carrao river, Venezuela – 979 m (longest single drop 807 m) 2 Tugela Falls, Tugela river, South Africa – 948 m 3 Ramnefjellsfossen, Josedal Glacier, Nesdale, Norway – 800 m 4 Mongefossen Falls, Monge river, Mongebekk, Norway – 774 m 5 Gocta Cataracta, Cocahuayco river, Peru – 771 m 6 Mutarazi Falls, Mutarazi river, Zimbabwe – 762 m 7 Yosemite Falls, Yosemite Creek California, USA – 739 m 8 Ostre Mardola Foss, Mardals rivver, Eikisdal, Norway – 656 m 9 Tyssestrengane Falls, Tysso river, Hardanger, Norway – 646 m 10 Cuquenan Falls, Arabopo river, Venezuela – 610 m

  The flow of many waterfalls varies according to the season, and some have been reduced by building dams to harness their power for hydro-electric plants.   The flow of the Boyoma waterfall is equivalent to 17m. litres (36m. gall) a second –enough to fill more than 140,000 baths per second, or enough for every person on Earth to have two baths a day! 1 Boyoma (Stanley), Democratic Republic of Congo –17,000 m 3 /sec 2 Khone,Laos* –11,330 m 3 /sec 3 Niagra (Horseshoe), Canada –5,830 m 3 /sec 4 Grande, Uruguay –4,500 m 3 /sec 5 Paulo Afonso, Brazil –2,800 m 3 /sec * Widest waterfall based on volume of water at 10.8 km

  The source of the Nile was discovered by Europeans in 1858 when British explorer John Hanning Speke reached Lake Victoria Nyanza, in what is now Burundi. About one hundred years later, in 1953, the source of the Amazon was identified as a stream called Huarco flowing from the Misuie glacier in the Peruvian Andes mountains. By following the Amazon from its source and up the Rio Para, it is possible to sail for 6,750 km, which is slightly more than the length of the Nile. But geographers do not consider the entire route to be part of the Amazon basin, so the Nile is considered the world’s longest river.     1 Nile * flows through Burundi, Dem, Rep of Congo, Egypt , Eritrea, Ethiopia, Kenya, Rwanda, Sudan, Tanzania, Uganda –6,695 km 2 Amazon flows through Peru and Brazil –6,448 km 3 Chang Jiang (Yangtze) flows through China –6,378 km 4 Amur flows through China and Russia –4,415 km * In 2006 the British and New Zealand Ascend the Nile team sailed from the mouth to the source

  The Americas are named after the explorer Amerigo Vespucci (1451 –1512). Africa was perhaps originally a Berber tribal name. This was adopted by the Romans as the name of their province and later spread to the whole continent.   The name of Europe may simply mean mainland. Asia is probably from the Assyrian, asu, meaning  sunrise or east. Australia is Latin for southern; Australia, with New Zealand and other islands, is also considered as part of Oceania, a name invented by the geographer Conard Male-Brun (1775 –1826). Antarctica is Greek for opposite the Arctic.Arctic comes from the Greek for bear, because the region lies under the stars of the Great Bear constellation.

    Geysers are jets of boiling water and steam that erupt from beneath the ground where water is heated by volcanic activity. The name geyser comes from a hot spring called Geysir at Haukadalur, Iceland. Yellowstone National Park, Wyoming, USA has more geysers than anywhere else. There are 500 active ones including Steamboat, which erupts to a height of 120 m, and Old Faithful , which erupts about every 91 minutes.

  Sea level is the average height of the sea at a point midway between high and low tides. The shore of the Dead sea is the lowest exposed ground below sea level. Some land in Antarctica is 2,538 m below sea level, but is covered by 2,100m deep ice cap.   1 Dead Sea, Israel/Jordan –400, below sea level 2 Lake Assa, Djibouti –156 m below sea level 3 Turfan Depression, China –154 m below sea level 4 Qattara Depression, Egypyt –133 m below sea level 5 Mangyshlak Penninsula, Kazakhastan –132 m below sea level

  An island is a piece of land surrounded by water. Australia is so large it is a continent, not an island; otherwise it would rank first. The Smallest island is Pitcairn, at 4.53 sq km(1.75 sq miles).   1 Greenland (Kalaatdlit Nunaat) –2,175,600 sq km 2 New Guinea – 789,000 sq km 3 Borneo –751,000 sq km 4 Madagascar (Malagasy Republic) –587,041 sq km 5 Baffin Island, Canada –507,451 sq km 6 Sumatra, Indonesia –422,200 sq km 7 Honshu, Japan –230,092 sq km 8 Great Britain –218,041 sq km 9 Victoria Island, Canada –217,290 sq km 10 Ellesmere Island, Canada –196,236 sq km 11 Celebs, Indonesia –179,000 sq km 12 South Island, New Zealand –151,971 sq km 13 Java, Indonesia –126,900 sq km 14 North Island, New Zealand –151,971 sq km 15 Newfoundland , Canada –108,860 sq km 16 Cuba –104,945 sq km 17 Luzon, Philippines –104,688 sq km 18 Iceland –102,819 sq km 19 Mindanao, Philippines –94,630  sq km 20 Ireland –84,406 sq km (Area excludes offshore islands

    People used to think that Kangchenjunga in Nepal/India was the highest mountain . Then the Great Trigonometrical Survey of India measured all the country’s land features. The survey was completed in 1852 and showed that Everest (then called peak XV) was the world’s highest mountain. Everest’s height was then reckoned to be 8.840 m (29,002 ft). This has since been adjusted as improved measuring methods have been used. The mountain’s name was suggested in 1865 as a tribute to Sir George Everest, the Surveyor General of India, who had led the survey. 1 Everest, Nepal/China – 8,850 m 2 k2 (Chogori), Pakistan/China – 8,607 m 3 Kangchenjunga,Nepal/India – 8,598 m 4 Lhotse, Nepal/China – 8,511 m 5 Makalu I, Nepal/China – 8,481 m

  The height of mountains is usually measured from sea level. Mauna Kea in Hawaii is only 4,245 m (13,957 ft) above sea level, but it rises a total of 10,203 m (33,44 ft) from the floor of the Pacific Ocean, Making its real height 1,353 m (4,439 ft) greater than Mount Everest!

  Deserts cover about a third of the world’s land area. They range from extremely arid and barren sandy deserts (about four per cent of the total land surface of the globe), through arid (15 per cent) to semi-arid (just under 15 per cent). Most deserts have features of all these, with one zone merging into the next, so the start and finish of any desert is not exact. Many of the world’s largest deserts are broken down by geographers into smaller desert regions –the Australian Desert includes the Gibson, Great Sandy, Great Victoria and Simpson, for example. 1 Sahara Northern Africa – 9,100,000 sq km 2 Australian, Australia (Includes Gibson, Great Sandy, Great Victoria and Simpson) – 3,400,00 sq km 3 Arabian Peninsula, Southwest Asia (Includes an-Nafud and Rub al khali) – 2,600,000 sq km 4 Turkestan, Central Asia (Includes Kara-Kum and Kyzylkum) – 1,900,000 sq km 5 Gobi, Central Asia – 1,300,000 sq km 6 North American Desert, US/Mexico (Includes Great Basin, Mojave, Sonora

    Minerals are naturally occurring substance with a definite chemical composition. Most mineral names end in “ite”. Many have a practical use or contain a chemical compound or element that can be extracted and used commercially. Bauxite, for instance, is the main source of aluminium. Gems are minerals that are highly prized for their rarity or appearance, e.g. diamonds, sapphires, emeralds and rubies.

    The rock formerly known as Ayers Rock in Northern Territory, Australia, is believed to be the world’s largest free-standing rock. It is made of sandstone and is 335 m (1,100 ft) high, 3.6 km (2.2 miles) long and 2 km (1.5 miles) wide. It was originally called after South Australian premier Sir Henry Ayers, but it is now known by the name given to it by local Aborigines, to whom it is scared.

  There are three categories of rock- igneous, sedimentary and metamorphic .   Igneous rocks originate deep in the Earth. They erupt from volcanoes as magma and cool or solidify as they rise to the upper layers. Basalt is an igneous rock and so is granite, a very hard rock often used in building . Pumice stone is a soft igneous rock that is ejected from volcanoes. As it cools, it often fills with so many air bubbles that it floats in water.   Sedimentary rocks can be formed by deposits in water and occasionally by wind. Sandstone is a common example. Organic sedimentary rocks are formed by living plants and animals – coal comes from plant matter and limestone from the  calcium from billions of plants and animals. chemical sedimentary rocks occur when chemical processes take place and minerals are deposited. Metamorphic rocks are Igneous or sedimentary rocks that have changed as a result of high temperatures or pressures. State used on roofs is a familiar example.

  The Mohs scale, named after German mineralogist Friedrich Mohs (1773-1839), is used for comparing the relative hardness of minerals. Each minerals on the scale can be scratched by the harder ones below it.     Mohs scale No              Substance 1                Talc 2                Gypsum 3                Calcite 4                Fluorite 5                Apatite 6                Orthoclase 7                Quartz 8                Topaz 9                Corundum 10              Diamond

    Many meteorites land in the sea and in unpopulated areas so they are never seen. The Hoba meterorite, the largest in the world, was found in Namibia in 1920. It measure 2.73 x 2.43 m (9 X 8 ft) and is 82 per cent iron and 16 per cent nickel. It weighs more than 60 tonnes.     Second largest is the Tent, found in Greenland in 1894 and now known by its original Eskimo name, Ahnighito. This meteorite weighs about 57.3 tonnes and is on display in the New York Museum of Natural History.

  About 500 meteroites reach Earth every year. Many collision sites have been altered by weather over millions of years, and scientists are unsure whether some craters are actually the craters of extinct volcanoes. Those below are all agreed to be meteorite craters.  1 Verdefort, South Africa 300 km (186 miles) in diameter 2 Sudbury, Ontario, Canada 250 km (155 miles) in diameter 3 Chicxulub, Yucatan, Mexico 170 km (106 miles) in diameter 4 Manicougan, Canada 100 km (62 miles) in diameter 5 Popigal, Russia 100 km (62 miles) in diameter

    The Earth is made up of a number of layers. At the top is the crust – the thinnest layers. Next is the mantle, then the outer and inner cores. The outer core is probably liquid and the inner core solid.

    Year: 2010 Event: Atlantis, Discovery and Endeavour are to be progressively taken out of service and replace by NASA’s Orion spacecraft in a programme that will take astronauts back to the Moon and to Mars.

  Even the most beautiful, multi-coloured coral reefs can look quite drab underwater. Everything looks very blue-green because the water filters out red and yellow light. However, if you shine a beam of white light underwater the full range of colours is magically revealed.

    Water is slightly blue, but this is only obvious when you see it in large amounts, and when the water is not stained by particles, such as sand or mud. Clear seawater in bright sunshine, as around this coral atoll, looks a rich blue because the water has absorbed other colours in the light.

    Absorbing light contains all the colours of the rainbow, but colours of light more than others. water absorbs colours at the red end of the spectrum much better than those at the blue-green end, which penetrate much deeper.

    Planet Earth is a watery place, with more than 70 per cent of its surface cover in seawater. Most of this water is found inn five oceans – giant hollows that have filled with salty water of the remaining surface water, most is locked up in ice around the North and South Poles. The water in lakes, river, clouds, soils and living organisms is small by comparison, but very important.

    Scientist think that the oceans formed nearly 4 billion years ago. The ocean water probably came from steam, which was released by erupting volcanoes. The steam cooled and turned to water in the atmosphere, then fell to Earth as rain. This collected in low-lying areas to create oceans.

    The damage to coral reefs by global warming, pollution and fishing is threatening to destroy the fragile underwater life of the Earth. Without intervention 70% of the world’s coral reefs will have died within 50 years. 2008 was International Year of the Reef –a worldwide campaign to raise awareness about the value and importance of coral reefs and threats to their sustainability.

    Year: 2009 Event: Virgin Galactic plans space tourism flights to over 100 km (62 miles) in SpaceShipOne, which carries six passengers at a cost of $200,000 per person.

    Date: 15-16 October 2003 Event: Chinese astronaut Lang Liwei made eight orbits of Earth in a Shenzhou 5 spacecraft. China made its second flight, Shenzhou 6, with two astronauts on 12-16 October 2005.

    Date: 28 April – 6 May 2001 Event: US millionaire Dennis Tito became the first space tourist, paying $20 million for his Russian Soyuz TM-32 flight to the International Space Station.

    Date: 2 November 2000 Event: An American and Russian crew began living abroad the International Space Station.

    Date: 4 December 1998 Event: First stage of the International Space Station was established.

  Date: 26 September 1996 Event: On her 5th mission, US astronaut Shannon Lucid completed 188 days abroad the Russian Mir station, setting a world record for women. Lucid was born in China. She flew more missions than any woman and at 53 was the oldest female in space.