10 of the most mysterious structures on the Earth's surface
Probably, their origin, we never will understand
We often think of the strange features of alien worlds that can not be explained. We think that if we just get in there and look at everything closely, how everything will become clear. Well, well: at home, on Earth, full details of its own geological history - to touch them easy to understand and still does not work.
1. Sand dunes Mount Baldy
Mount Baldy - the highest sand dune on the south shore of Lake Michgan. Her height -. 37 m Indiana touts it as a "live" tourist attraction, because every year dune moves a meter or two. Dune started to move when visitors trampled all the grass that held the dune in one place. Secrets of what is happening there - the movement caused by the wind. But scientists have puzzled over the other capability dunes - to absorb children.
In July, 2013. Nathan Uossner six fell in the sand when it suddenly formed under three-meter hole. Three hours later, the child dug up - fortunately alive. The next month, has another hole. Inside, the deep sand dunes air voids can not be formed, because the sand all fill immediately.
"It seems that we are witnessing a new geological phenomenon", - says geologist Erin Erdzhilen, which conducts research. On that day, when the boy fell into the sand, she worked side by side, and are now interested in finding emotional explanations.
The dune might be trees, which are first put there, then decayed, and the resulting formed opening. Once it was mined sand for glass production, so that it could be because of human intervention. Now dune closed to the public.
2. Sahara Eye
Structure Rishat, aka "Eye of the Sahara" - a strange circular formation 30 km in width in the middle of the desert. It consists of concentric circles in various shades of blue and clearly visible from space. For a long time it was believed that the Eye of the Sahara - a crater. But recent studies show that this is certainly not the case. Heat and impact strength meteor always leaves the same chemical compounds, including carbon dioxide form called coesite. Richat In the structure of this element is not contained. Some note the similarity of the Sahara Eyes of abandoned Plato (Plato) descriptions of Atlantis and suggest that it may be that at this place once stood a mythical city. But even if we assume that the Atlantean civilization existed at all, the experiments show that the structure was formed about a hundred million years ago, so it is definitely a natural, not man-made. The only human habitation nearby - this is a temporary camp adventure lovers.
According to another version Rishat structure - it is the top of the volcano, but the cone had not convex, as is usual. Leading theory is that in this place a long time erosion occurred. This explains the very structure of education, but its perfectly round shape remains a mystery.
3. Sunburn Desert
The stones in deserts are often covered with a thin layer of a substance whose color varies from light tan to black. Throughout the world, ancient people were scraped off the layer and painted petroglyphs. This phenomenon is found in the deserts of the world, but the reasons for the formation of the desert sun are unknown.
Plaque consists mostly of clay and a third of the iron and manganese, which is required both its color and mystery. In particular, the concentration of manganese in the desert tan can be 50 times higher than in the surrounding landscape. Laboratory experiments have shown that micro-organisms can influence the creation of this item. However, bacteria are able to produce material more quickly than the desert tan formed - 1000 years on the stones accumulate a layer of approximately the thickness of a human hair.
Some researchers believe that the material is leached from the rock and is formed from the dust falling from the sky, because the biological explanation in the material contains too much silica. Others believe that a number of iron and manganese must be life. A recent suggestion reconciles both points of view: tan desert can produce microorganisms with an unusual type of biochemistry. These microorganisms may be derived from an unknown ancestor - even possible, that's life based on silicon rather than carbon.
Uturunku - volcano in southwest Bolivia, 6000 meters high in the last time it erupted 300,000 years ago.. Satellite observations in the past 20 years have shown that the underground volcanic hearth filled ten times faster than the similar volcanic systems - one cubic meter per second of magma. As a result, the land within a radius of 70 km from the volcano rises to a couple of centimeters each year.
The first question unanswered: how long this process goes? Geomorphology studied the neighborhood: it seems it all started relatively recently, but on this issue more work and work.
Another mystery: how Uturunku will behave in the future? Shan de Silva from Oregon State University studying the volcano of 2006. He believes that this can be a potential supervolcano. But other geologists do not see any evidence of this assertion. In any case, on average, between eruptions in southwestern Bolivia passes just 300 000 years, so Uturunku seems, will soon cease to be idle.
5. The Permian extinction
The most interesting extinction in Earth's history happened at the end of the Permian period. According to studies, 93-97% then vanished species of living creatures on our planet. The causes of extinction rise to perhaps the most heated debates in paleontology.
The most obvious "suspects" - meteorites. As evidence, proponents refer to the crater in Antarctica, but the arguments, to put it mildly, weak.
Another suggestion - volcanoes. The most likely candidates - Siberian traps, formed at that time. The researchers studied the border of extinction in Canada and found a layer of ash. They suggest that the volcanic eruptions set fire to huge deposits of coal, which made greenhouse effect. But even without the ignition of coal volcanoes could throw into the air enough sulphate to prevent the sun's rays reach the earth and cause acid rain. Volcanism could also play a more subtle role. Team MIT blames microbe called metanosartsina. These unicellular archaea produce methane and thrive on nickel and carbon dioxide, whose number of eruptions increased substantially. As a greenhouse gas, methane is 30 times stronger than carbon dioxide. Perhaps he was the cause of a fatal warming world.
6. Lake Hiller
Hiller - it is the least studied pink lake in the world. It was discovered in 1802, the year in an ecologically clean area of the Australian desert. View on Hiller is possible only from the air - the measures taken to protect wildlife around the lake. Therefore, the lake is still unknown.
The lake is the color "pink bubble gum" to swim safely, though the water in it is very salty. There are three possible reasons for the unusual color of the water, based on our knowledge of other pink lakes around the world.
Tint Rose Lake in Western Australia less saturated than Hiller lake. Color Pink Lake due to a combination of shrimp and microorganisms, known as halobacteria (which actually does not bacteria). The lake Hiller can live these bacteria, or Achaia, but also the same halobacteria.
Similar to the color of the lake Retba in Senegal. The salt content in the water Retba also very large, but the color is caused by algae.
Finally, the color of the lake Hiller may not be associated with living organisms - the cause may be chemical reactions. Salt lake can react with dissolved in water with sodium carbonate or other unique composition of rocks surrounding the lake.
There is another option - an optical illusion. His, however, long been denied: the water from Hiller remain pink even in the bottle.
7. formed Hawaii
The chain of the Hawaiian Islands - one of many formed is believed to be in the "hot spot". Hot spots - are the regions where the magma rises to the surface and stays in one place for tens of millions of years, while over her continental drift. The result is a chain of volcanic islands, the youngest of which is an active volcano. They are 5% volcanoes located away from plate tectonics.
The cause of hot spots - one of the biggest mysteries in geology. According to the leading theory, the plume of hot magma rises from the border between the mantle and the inner core of the Earth, that is, from a depth of 3000 km. The theory is called "mantle plume". However, it is unknown whether mantle plumes exist in reality. Laboratory experiments and theoretical models suggest that this is at least possible.
In 2011, a team at the Massachusetts Institute of Technology released a study in which he called the most suitable "candidate" for the role of the plume - thermal anomaly at 725 km west of the Hawaiian Islands, which perhaps is only 800 km below the surface. This prisoner trapped in the flow of molten magma has passed through the upper mantle, and then broke through the earth's crust.
8. Age of the Grand Canyon
Grand Canyon - one of the most famous geological formations on Earth. And one of the most studied. Despite this, the consensus about his age there. Some scientists believe that he is about six million years, others - about 70 million.
two camps also do not agree that there has served the cause of the Colorado River canyon, river or simply paved its direction on the already formed canyon. There are more and more evidence to support both hypotheses, but to the truth is still far away.
9. dipping just reset
Rift - a crack in the earth's surface. Fault parties can move relative to each other in any direction. They are rarely vertical. The upper part is called the hanging wall, and bottom - the sole. Often also reset with an offset along the dip - in this case, the hanging wall moves up or, conversely, down to the sole. Typically, these faults are very steep.
Reset offset by a fall in which the hanging wall moves towards the sole, referred to simply reset. A simple discharge with a gentle slope less than 30 degrees are called simple dipping faults. The problem is that they do not need to exist. Our models show that immediately after the formation they need to turn into a steep breaks. This phenomenon is called "the greatest tectonic paradox".
Dipping just reset must connect, because the friction between the two sides should stop their movement. Usually, when the parties adhere, creates tension, growing until the friction disappears, usually as a result of the earthquake. But there is no evidence that the simple dipping faults ever caused the earthquake, although they should be.
Our main geological models have significant blind spots. In addition, our laboratory measurements of cracks and fractures in the friction did not coincide with what is happening in reality.
10. The Messinian salinity crisis
About six million years ago the Mediterranean Sea has become a desert. It lasted 630 000 years, and now this era is called Messina peak salinity. Scientists believe that the sea has become a desert because suddenly lost access to the Atlantic Ocean. Why - a mystery.
One theory is that due to the growth of the polar ice caps, sea levels dropped, and as a result formed a small area of land, which blocked access to the ocean. In addition, tectonic collision could raise the sea floor not far from Gibraltar, they raised the Alps. Thus, the territory of modern Spain and Morocco could connect and the time to close the strait. More unusual theory advanced geology, University of London Royal Holloway: washing out the bottom of the Atlantic Ocean. As a result, a piece of land, is still linked to the ocean floor to its west end, allowed the easy rocks to the surface. They surfaced and took this place, thus creating a huge natural dam across the Strait of Gibraltar, which the sea again flooded only half a million years later.