Hidden Unseen: 2012-06-03

Top 10 Beautiful Natural Holes in the Earth

Nature never stops to amaze us with its magnificent phenomenon just like these inexplicable holes in the ground. These holes may be formed gradually or suddenly, and are found worldwide. This is a list of beautiful natural holes from around the World, which have become popular tourist destinations.

1. Dean's Blue Hole, Bahamas

Dean's Blue Hole is the world's deepest known blue hole with seawater. It plunges 202 metres (663 ft) in a bay west of Clarence Town on Long Island, Bahamas.

Dean's Blue Hole is named after the family name of local landowners. It is located in a small bay, divided from the open sea with small peninsula. Over the last few years this sinkhole has become a scene of world-class free-diving.

2. Bimmah Sinkhole, Oman

This sinkhole was formed naturally when the ground over unstable layers collapsed on itself. There is an underwater tunnel leading to the sea 500 metres (1,650ft) away, leading to a mixing of fresh and sea water in the hole. It is possible to dive this, however due to possible extreme tidal conditions, caution is advised.

The Sinkhole is located about 6km (3.7mi) from Dibab along the coast graded road from Muscat to Sur. Right now a big motorway is under construction next to it.

3. The Great Blue Hole, Belize

The Great Blue Hole is a large submarine sinkhole off the coast of Belize. It lies near the center of Lighthouse Reef, a small atoll 70 km (43 mi) from the mainland and Belize City. The hole is circular in shape, over 300 m (984 ft) across and 124 m (407 ft) deep. The Great Blue Hole is a part of the larger Belize Barrier Reef Reserve System, a World Heritage Site of the United Nations Educational, Scientific and Cultural Organization (UNESCO).

This is a popular spot amongst recreational scuba divers, who are lured by the opportunity to dive in crystal-clear water and meet several species of fish, including giant groupers, nurse sharks and several types of reef sharks such as the Caribbean reef shark and the Blacktip shark.

4. Ik Kil, Mexico

Ik Kil is a well known sinkhole outside Pisté in the Municipality of Tinúm, Yucatán, Mexico, It is located in the northern center of the Yucatán Peninsula and is part of the Ik Kil Archeological Park near Chichen Itza. It is open to the public for swimming and is often included in bus tours.

This sinkhole is open to the sky with the water level about 26 metres (85 ft) below ground level. There is a carved stairway down to a swimming platform. Ik Kil is about 60 metres (200 ft) in diameter and about 40 metres (130 ft) deep. There are vines which reach from the opening all the way down to the water along with small waterfalls. Also, there are black catfish which swim in the sinkhole.

5. Red Lake, Croatia

Red Lake is a sinkhole containing a karst lake near the city of Imotski, Croatia. It is known for its numerous caves and remarkably high cliffs, reaching over 241 metres (790ft) above normal water level and continuing below the water level. The total explored depth of this sinkhole is approximately 530 metres (1,740ft) with a volume of roughly 25-30 million cubic meters, thus it is the third largest sinkhole in the world. Water drains out of the basin through underground waterways that descend below the level of the lake floor.

6. Zacatón, Mexico

Zacatón is a thermal water filled sinkhole belonging to the Zacatón system - a group of unusual karst features located in Aldama Municipality in the northeastern state of Tamaulipas, Mexico. It is the deepest known water-filled sinkhole in the world with a total depth of 339 metres (1,112 ft).

Zacatón is the only sinkhole of the five located in Rancho La Azufrosa to have any noticeable water flow. The name Zacatón comes from the free-floating islands of zacate grass which move around on the surface with the wind.

7. Morning Glory Pool (Hole), Wyoming, USA

This is one of the most prominent and prettiest thermal pools in the Yellowstone park. The depth of this pool ( natural hole) is 4 meters (13ft). The "Morning Glory Pool" was given its name in the 1880 for its resemblance to a morning glory flower.

The distinct color of the pool is due to bacteria which inhabit the water. However, this pool was once in danger of losing its colors when the Grand Loop Road used to pass close to it, which increased the likelihood of thoughtless visitors throwing coins into it - thus causing the pool to cool and jeopardize the existence of the color-causing bacteria that thrive within. Today, you'll have to do a little walking along the Upper Geyser Basin to get to the pool, and it's well worth the exercise.

8. Neversink Pit, Alabama, USA

Neversink Pit is a limestone sinkhole in Alabama, and it’s one of the most-photographed sinkholes in the world because of its beautiful fern-covered ledges and waterfalls. The hole is about 40 feet (12m) wide at the top, but it expands to 100 feet (30m) at its bottom, which is 162 feet (50m) from the ground. Neversink is home to bats and several rare and endangered fern species.

9. Giant's Kettle in Rovaniemi, Finland

An interesting place to visit is the giant's kettles located in Rovaniemi, Finland. The largest giant's kettles have diameters of 5,7 - 8 metres (18-26ft) and a height of 15,4 metres (50ft). Giant's kettle from picture is one of the largest and most beautiful in the region.

10. Balaa Sinkhole, Lebanon

Bala'a sinkhole is located in northern Lebanon. It is approximately 250 m (820ft) deep sinkhole. The most amazing feature is waterfall which has percolated one side of sinkhole, creating three natural bridges one above the other.

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Colourfull Salt Ponds at San Francisco Bay

If you ever fly over San Francisco Bay, be sure to peer out of the window to catch a glimpse of one of the world's most incredibly coloured landscapes - the salt evaporation ponds operated by Cargill, Inc.

Salt evaporation ponds are shallow artificial ponds designed to produce salts from sea water or other brines. The seawater or brine is fed into large ponds and water is drawn out through natural evaporation which allows the salt to be subsequently harvested. During the five years it takes for the bay water to mature into salt brine, it is moved from one evaporation pond to another. In the final stages, when the brine is fully saturated, it is pumped to the crystalizer where a bed of salt 5 to 8 inches thick is ready for harvest.

Salt ponds range from blue green to deep magenta – colored naturally by the microorganisms that thrive as salinity levels increase. The color indicates the salinity of the ponds and the type of microorganisms that’s breeding on it. Three microorganisms in particular, Synechococcus, Halobacteria, and Dunaliella, influence the color of salt ponds.

In the low-salinity ponds, both color and microbiology match the blue green waters of San Francisco Bay. As the brines concentrate, several algae, including Dunaliella, impart a green cast to the brines. With increasing salinity, Dunaliella out-competes other microorganisms and hues vary from pale green to bright chartreuse. About midway through the pond system, the increased salinity promotes huge populations of tiny brine shrimp, which clarify the brine and darken it. The saltiest brine, or pickle, appears deep red, because Halobacteria take over and the hypersaline brine triggers a red pigment to form in the Dunaliella’s protoplasm.

The palette of salt pond colors reflects an unusual micro-biota. Yet it is more than just a curiosity of nature. The algae and other microorganisms create the basis for a rich ecosystem, supporting more than a million shorebirds, waterfowl and other wildlife. At the same time, these tiny creatures regulate water quality -- which promotes development of a higher quality salt.

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Lake Retba or Lac Rose

Lake Retba or Lac Rose lies north of the Cap Vert peninsula of Senegal, north east of Dakar. Depending on the time of day, the lake changes colour from a light purple to a deep scarlet pink. The unusual colouring of the water is caused by harmless halophilic bacteria that thrive in the lake’s high-salinity environment. The color is particularly visible during the dry season.

"The strawberry colour is produced by salt-loving organism Dunaliella salina. They produce a red pigment that absorbs and uses the energy of sunlight to create more energy, turning the water pink," said Michael Danson, an expert in bacteria from Britain's Bath University.

Covering an area of about 3 sq km, the lake is located about 35km north-east of Senegal’s capital Dakar. Since the 1970s, local residents have been mining Lake Retba for its salt, which they use mainly to preserve fish. Waist-deep in water, the men scrape the bottom of the lake to harvest this universally useful mineral which they collect in baskets in their wooden canoes. The salt is then taken back to shore where it is sectioned into small mounds. Dotted along the lake’s shore, these pristine white hills of salt create an arresting contrast against the pink of the lake. In order to protect their skin from the extreme salinity of the water, the workers rub their skin with shea butter, produced from shea nuts obtained from the Shea nut tree.

Lakes like Retba and the Dead Sea, which have high salt, were once thought to be incompatible with life. The salt content is very high, as much as 40%, which is almost one and a half times higher than in the Dead Sea - three hundred and eighty grams per liter.

Lake Retba is well known for having been the end point of the famed Dakar Rally, which has since been relocated to South America.

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Bulgarian 'vampires' from Middle Ages

If you thought vampires were simply the stuff of myth and legend - and perhaps the odd teen horror film - think again. Archaeologists in Bulgaria have unearthed two skeletons from the Middle Ages pierced through the chest with iron rods to keep them from turning into the undead.

They are the latest in a succession of finds across western and central Europe which shed new light on just how seriously people took the threat of vampires and how those beliefs transformed into the modern myth.

Find: Two skeletons, believed to be those of suspected Medieval vampires, were discovered with iron poles plunged through their chests in the Bulgarian Black Sea town of Sozopol
The two skeletons, believed to be around 800 years old, were discovered during an archaeological dig near a monastery in the Bulgarian Black Sea town of Sozopol.
Bulgaria's national history museum chief Bozhidar Dimitrov said: 'These two skeletons stabbed with rods illustrate a practice which was common in some Bulgarian villages up until the first decade of the 20th century.'

A close up of one of the 'vampire' skeletons discovered with a metal bar through its chest

According to pagan beliefs, people who were considered bad during their lifetimes might turn into vampires after death unless stabbed in the chest with an iron or wooden rod before being buried. People believed the rod would also pin them down in their graves to prevent them from leaving at midnight and terrorising the living, the historian explained.

According to Mr Dimitrov over 100 buried people whose corpses were stabbed to prevent them from becoming vampires have been discovered across Bulgaria over the years. He added: 'I do not know why an ordinary discovery like that became so popular. Perhaps because of the mysteriousness of the word "vampire". 'These people were believed to be evil while they were alive, and it was believed that they would become vampires once they are dead, continuing to torment people.' According to Dimitrov, 'vampires' were often aristocrats and clerics. He added: 'The curious thing is that there are no women among them. They were not afraid of witches.'

However last month Italian researchers discovered what they believed to be the remains of a female 'vampire' in Venice - buried with a brick jammed between her jaws to prevent her feeding on victims of a plague which swept the city in the 16th century.

Matteo Borrini, an anthropologist from the University of Florence, said the discovery on the small island of Lazzaretto Nuovo in the Venice lagoon supported the medieval belief that vampires were behind the spread of plagues like the Black Death.

Find: The two skeletons were discovered during a dig outside a monastery in the Bulgarian Black Sea town of Sozopol

Sozopol: According to the head of Bulgaria's natural history museum 100 corpses of people who were stabbed to prevent them from becoming vampires have been discovered across the country over the years

The skeleton was unearthed in a mass grave from the Venetian plague of 1576 - in which the artist Titian died - on Lazzaretto Nuovo, which lies around two miles northeast of Venice and was used as a sanitorium for plague sufferers.

Borrini said: 'This is the first time that archaeology has succeeded in reconstructing the ritual of exorcism of a vampire. 'This helps ... authenticate how the myth of vampires was born.'

The succession of plagues which ravaged Europe between 1300 and 1700 fostered the belief in vampires, mainly because the decomposition of corpses was not well understood, Borrini said. Gravediggers reopening mass graves would sometimes come across bodies bloated by gas, with hair still growing, and blood seeping from their mouths and believe them to be still alive. The shrouds used to cover the faces of the dead were often decayed by bacteria in the mouth, revealing the corpse's teeth, and vampires became known as 'shroud-eaters.'

According to medieval medical and religious texts, the 'undead' were believed to spread pestilence in order to suck the remaining life from corpses until they acquired the strength to return to the streets again.

The remains of a female 'vampire' from 16th-century Venice, buried with a brick in her mouth to prevent her feasting on plague victims

'To kill the vampire you had to remove the shroud from its mouth, which was its food like the milk of a child, and put something uneatable in there,' said Borrini. 'It's possible that other corpses have been found with bricks in their mouths, but this is the first time the ritual has been recognised.'

While legends about blood-drinking ghouls date back thousands of years, the modern figure of the vampire was encapsulated in the Irish author Bram Stoker's 1897 novel 'Dracula,' based on 18th century eastern European folktales.

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Transit of Venus - 5 June 2012

Stargazers from across the globe gathered together to watch one of the rarest astronomical spectacles today. From the U.S. and UK to South Korea, people around the world turned their attention to the daytime sky to make sure they caught the planet Venus passing directly between the sun and Earth - a transit that won't occur again for another 105 years. The transit of Venus happens in pairs eight years apart - but then with more than a century between cycles.

During the pass, Venus appears as a small, dark round spot moving across the face of the sun, like a bug on a dinner plate.

Enthralling: Venus is silhouetted as it crosses in front of the sun as it sets behind the Kansas City, Missouri skyline on Tuesday, June 5, 2012

Planet Venus is seen as a black dot as it transits across the Sun during sunrise in Sofia, Bulgaria on June 6, 2012

The transit of Venus taken from Burton Dassett between Stratford Upon Avon and Banbury, UK

Venus is seen transiting across the Sun on June 6, 2012 outside Sarajevo

The planet Venus passes in front of the Sun as seen during the sunrise behind the Bratislava Castle in Bratislava, Slovakia, 06 June 2012

A bite out of the sun: This image of the transit was taken from Burton Dassett, between Stratford Upon Avon and Banbury

A close-up of the images from Burton Dassett show Venus just taking a nip out of the sun

'If you can see the mole on Cindy Crawford's face, you can see Venus,' Van Webster, a member of the Los Angeles Astronomical Society, told anyone who stopped by his telescope for a peek on Mount Hollywood.

For astronomers, the transit wasn't just a rare planetary spectacle. It was also one of those events they hoped would spark curiosity about the universe and our place in it.

Sul Ah Chim, a researcher at the Korea Astronomy and Space Science Institute in South Korea, said he hoped people see life from a larger perspective, and 'not get caught up in their small, everyday problems.'

'When you think about it from the context of the universe, 105 years is a very short period of time and the Earth is only a small, pale blue spot,' he said.

While astronomers used the latest technology to document the transit, American astronaut Don Pettit aboard the International Space Station attempted to take the clearest-ever photos of the event and post them online.

A composite sequence photo of the steps of the entire transit of Venus seen over the sky of Seoul, South Korea, 6 June 2012

NASA had all eyes on the transit, ensuring to capture the images for posterity - if they had messed the shot up, it's a 105-year-wait for the next one

Dramatic: This image provided by NASA shows the Solar Dynamic Observatory's ultra-high definition view of Venus on it's transit, an event which will not occur for another 105 years

Impressive: This image provided by NASA shows the Solar Dynamic Observatory's ultra-high definition view of Venus, black dot at top center, passing in front of the sun on Tuesday, June 5, 2012

Bright: This is just one frame of an astonishing short video put online by NASA of Venus passing the sun

near the KCPL building in downtown Kansas City, Mo

Scene: A view of the Sun as the planet Venus passes in between the Sun and the Earth in New York, New York, USA, 05 June 2012

Many ways to view it, many places in the world to see it: Professor Hashim Ahmed Yousif al-Sayed, dean at the College of Science at the University of Bahrain, projects the sun's image for students

Meanwhile, terrestrial stargazers were warned to only look at the celestial event with a properly filtered telescope or cardboard eclipse glasses. If the sun is viewed directly, permanent eye damage could result.

In Los Angeles, throngs jammed Mount Hollywood where the Griffith Observatory rolled out the red carpet for Venus. The last time the city witnessed a Venus transit was 130 years ago in 1882. A 2004 transit was not visible from the western U.S.

Telescopes with special filters were set up next to the lawn and people took turns peering at the sun before and during the transit. Astronomers and volunteers lectured about the rarity of a Venus pass to anyone who would listen.

Minutes before Venus first touched the outer edge of the sun, Sousa's 'Transit Of Venus March' blared through. The crowd turned their attention skyward. For nearly 18 minutes, Venus appeared as a black spot.

Jamie Jetton took the day off from work to bring her two nephews, six and 11, visiting from Arizona to the observatory. Sporting eclipse glasses, it took a little while before they spotted Venus.

'I'm still having fun. It's an experience. It's something we'll talk about for the rest of our lives,' she said.

The transit of Venus taken from Burton Dassett between Stratford Upon Avon and Banbury, UK - Venus has made a spectacular transit across the sun in a rare event that wont be witnesse again for over a hundred years

Venus crosses the sun from an observation point in Pakistan on June 6, 2012

Worldwide fascination: The planet Venus makes its transit across the Sun as seen from Kathmandu on June 6, 2012

Morning breaks: An observer looks through a telescope during sunrise in Vienna

Mesmerising: Spectators at Edgewater Park in Cleveland watch the sun set as the planet Venus crosses the upper right portion of the star, Tuesday, June 5, 2012

The planet Venus makes a transit as a person watches the sun set over the Great Salt Lake outside Salt Lake City, Utah, June 5, 2012

Bo Tan, a 32-year-old software engineer took a half day off from work and went with his co-workers to the observatory. He admitted he wasn't an astronomy buff but could not miss this opportunity.

He pointed his eclipse glasses at the sun and steadied his Nikon camera behind it to snap pictures. 'It makes you feel like a small speck in the universe,' he said.

In Mexico, at least 100 people lined up two hours early to view the event through telescopes or one of the 150 special viewing glasses on hand, officials said. Observation points were also set up at a dozen locations.

Venus, which is extremely hot, is one of Earth's two neighbors and is so close in size to our planet that scientists at times call them near-twins. During the transit, it will appear as a small dot.

This will be the seventh transit visible since German astronomer Johannes Kepler first predicted the phenomenon in the 17th century. Because of the shape and speed of Venus' orbit around the sun and its relationship to Earth's annual trip, transits occur in pairs separated by more than a century.

It's nowhere near as dramatic and awe-inspiring as a total solar eclipse, which sweeps a shadow across the Earth, but there will be six more of those this decade.

In Hawaii, hundreds of tourists and locals passed through an area of Waikiki Beach where the University of Hawaii set up eight telescopes and two large screens showing webcasts of the transit as seen from telescopes at volcanoes on other Hawaiian islands.

But minutes after Venus crossed into the sun's path, clouds rolled overhead and blocked the direct view.

'It's always the challenge of being in Hawaii - are you going to be able to see through the clouds,' said Greg Mansker, 49, of Pearl City, as he stood in line at a telescope.

The intermittent clouds didn't stop people from looking up through filters, but it did drive some to crowd the screens instead.

Spectacular: The planet Venus can be seen on its transit of the Sun, from Beijing

Last-in-a-lifetime: In this photo made using a red filter, Venus begins to pass in front of the sun, as visible from from Overland Park, Kan. on Tuesday

Impressive: A bird sits atop one of the domes of the landmark Taj Mahal as Venus, top left, begins to pass in front of the sun, as visible from Agra, India, Wednesday, June 6, 2012

The planet Venus makes its transit across the Sun as seen from Kathmandu

Venus is seen as a dot as it transits across the Sun on June 6, 2012 outside Sarajevo

Show: The planet Venus crosses the upper right portion of the sun as seen from Edgewater Park in Cleveland on Tuesday, June 5, 2012

Rarity: A view of the Sun as the planet Venus passes in between the Sun and the Earth in New York, New York, USA, 05 June 2012

Drawing near: In this handout image provided by NASA, the SDO satellite captures the approach of Venus before it transits across the face of the sun on June 5, 2012 from space

Rare: Handout image courtesy of NASA shows the planet Venus at the start of its transit of the Sun, June 5, 2012. One of the rarest astronomical events occurs on Tuesday and Wednesday when Venus passes directly between the sun and Earth, a transit that won't occur again until 2117
Jenny Kim, 39, of Honolulu, said she told her 11-year-old son the planet's crossing would be the only time he'd get to see the transit in person. 'I don't know what the future will be, so I think this will be good for him,' Kim said as she snapped photos of the webcast with her smartphone.

Astronomers also planned viewings at Pearl Harbor and Ko Olina.

NASA planned a watch party at its Goddard Visitor Center in Maryland with solar telescopes, 'Hubble-quality' images from its Solar Dynamics Observatory Mission and expert commentary and presentations.

Most people don't tend to gaze at the sun for long periods of time because it's painful and people instinctively look away. But there's the temptation to stare at it during sky shows like solar eclipses or transits of Venus.

The eye has a lens and if you stare at the sun, it concentrates sunlight on the retina and can burn a hole through it. It's similar to when you hold a magnifying glass under the blazing sun and light a piece of paper on fire.

It can take several hours for people to notice problems with their eyes but, by that time, the damage is done and, in some cases, irreversible.

During the 1970 solar eclipse visible from the eastern U.S., 145 burns of the retina were reported, according to the American Academy of Ophthalmology.

Experts from Hong Kong's Space Museum and local astronomical groups were organizing a viewing Wednesday outside the museum's building on the Kowloon waterfront overlooking the southern Chinese city's famed Victoria Harbor.

The transit is happening during a 6-hour, 40-minute span that began just after 6 p.m. EDT in the United States. What you can see and for how long depends on what the sun's doing in your region during that exact window, and the weather.

Those in most areas of North and Central America will see the start of the transit until the sun sets, while those in western Asia, the eastern half of Africa and most of Europe will catch the transit's end once the sun comes up.

Hawaii, Alaska, eastern Australia and eastern Asia including Japan, North and South Korea and eastern China will get the whole show since the entire transit will happen during daylight in those regions.

Spectacle: Venus begins to pass in front of the sun, as visible from New York, Tuesday, June 5, 2012

Vision: Venus, upper right, transits the sun as seen through a dark glass from Quito, Ecuador, Tuesday, June 5, 2012

Sight: Venus (top, R) crosses the sun's face as seen from Havana on June 5, 2012

Special: The small black dot seen at the top right of the sun is the planet Venus, as it transits across the face of the sun Tuesday, June 5, 2012, as seen from Mt. Trashmore in Virginia Beach, Va

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