Indonesia's Mount Merapi spews hot lava

Mount Merapi

Hot gas and molten lava from Mount Merapi has forced the evacuation of thousands of people this week, officials said Wednesday, warning that a large eruption at Indonesia's most dangerous volcano was still possible.
"It has the potential to spew bigger hot clouds," said Subandriyo, a vulcanologist monitoring Merapi's peak, adding that scorching ash and debris shot nearly two miles down the mountain's flank on nine separate occasions Wednesday.
The volcano's lava dome has swelled in recent weeks, raising concerns that it could suddenly collapse and send scalding clouds of gas and debris into populated areas.
Some scientists say a powerful May 27 earthquake that killed more than 5,700

people in area only 25 miles south of Merapi may have contributed to the increased activity at the volcano.
Subandriyo said the mountain appeared a little calmer than on Monday and Tuesday, but that it was still in a state of flux.
Puji Pujiono, leader of the United Nations disaster assessment and coordination team at the site, said 3,500 people living near the base were evacuated this week, many taken in trucks and cars to temporary shelters. Thousands living nearer to the peak had already been relocated.
Pujiono said a U.N. helicopter was to fly over the 9,800 foot peak later Wednesday, and that a status report would be filed later in the evening, but he did not think the mountain was any more dangerous than it was three weeks ago.
Merapi's last deadly eruption was in 1994, when it sent out a searing gas cloud that burned 60 people to death.
About 1,300 people were killed when it erupted in 1930.

Indonesia is located on the so-called Pacific "Ring of Fire," a string of volcanoes and fault lines that encircle the Pacific Basin. It has 76 volcanoes, the largest number of any nation.
In southern Japan, meanwhile, Mount Sakurajima erupted Wednesday and sent a plume of smoke about 3,300 feet into the air, the country's Weather Agency said, but there were no immediate reports of damage or injuries.
The eruption registered as moderate on the agency's scale for both the sound and the strength of the tremors it caused.
There was no other significant change in volcanic activity, the bulletin said. "We do not believe that a large-scale eruption is imminent," said agency official Akira Otani.
Authorities in the area have received no immediate reports of damage or injuries, according to police official Shoichi Araki in Kagoshima, across the bay from the volcano. Ash has been falling in the city for several days, he added.
The 3,686-foot Sakurajima is one of the most active of Japan's 108 volcanoes. It sits in Kagoshima Bay, about 590 miles southwest of Tokyo.

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Huge Variety of Marine Life Found in Deep Antarctic Waters

Carnivorous sponges, blind creepy-crawlies adorned with hairy antennae and ribbed worms are just some of the new characters recently found to inhabit the dark abysses of the Southern Ocean, an alien abode once thought devoid of such life.
Recent expeditions have uncloaked this polar region, finding nearly 600 organisms never described before and challenging some assumptions that deep-sea biodiversity is depressed.
The findings also suggest that all of Earth's marine life originated in Antarctic waters.

Carnivorous sponges, blind creepy-crawlies adorned with hairy antennae and ribbed worms are just some of the new characters recently found to inhabit the dark abysses of the Southern Ocean, an alien abode once thought devoid of such life.
Recent expeditions have uncloaked this polar region, finding nearly 600 organisms never described before and challenging some assumptions that deep-sea biodiversity is depressed.
The findings also suggest that all of Earth's marine life originated in Antarctic waters.
Scientists had assumed that the deep sea of the South Pole would follow similar trends in biodiversity documented for the Arctic.
"There are less species in the Arctic than around the equator," said one of the study scientists, Brigitte Ebbe, a taxonomist at the German Center for Marine Biodiversity Research. "People assumed that it would be the same if you went from the equator south, but it didn't prove to be true at all."
The findings, reported this week in the journal Nature, provide a more accurate picture of creatures in the southern deep sea and shed light on the evolution of biodiversity in the deep ocean, including ancient colonization dating back 65 million years
"The Antarctic deep sea is potentially the cradle of life of the global marine species," said lead author Angelika Brandt of the Zoological Institute and Zoological Museum at the University of Hamburg.

Deep dwellers
Between 2002 and 2005, an international team of scientists completed three research expeditions to the Weddell Sea aboard the German vessel Polarstern.
Part of the Southern Ocean, the Weddell Sea is bounded by an Antarctic bulge called Coats Land and the Antarctic Peninsula.
Ernest Shackleton's ship Endurance was trapped and crushed by ice in this sea in 1915. Shackleton and his entire crew survived. Shackleton died in 1922 of a heart attack on a different Antarctic expedition.
Part of the ANDEEP (Antarctic benthic deep-sea biodiversity) project, the team collected biological samples from regions between about 2,000 and 21,000 feet below the surface of the Weddell Sea and nearby areas.
In addition to cataloging biodiversity, the scientists aimed to determine how species intermingled within and between the deep and shallower waters and whether continental-shelf organisms colonized the deep ocean or vice versa.
The Weddell Sea is part of a vast ocean current and a critical source of deep water and possibly a mode of transport to the rest of the Southern Ocean.
Some of the scientists' findings indicate species originating in a single water domain did migrate to the Southern Ocean, and some even trekked across the globe and now inhabit the Arctic waters.
Many of the organisms have relatives in both the nearby shallower waters and even in other ocean basins.
Species finds included 674 species of isopods, an order of crustaceans, 80 percent of which were new to science.
Some of the isopods and marine worms spotted on the continental shelf sported vestiges of their deep-water past.
"On the shelf, the animals have eyes because they can see. There's light in the water. In the deep sea you don't really need them, so many animals get rid of their eyes," Ebbe told LiveScience.
"There were some [species] that are very closely related to eyeless isopods, and they are now living on the shelf. So that's an indication they have moved upward," Ebbe said.

Water travel
Many species living in the deep abyss of the Weddell Sea showed strong links with other oceans, particularly organisms that can disperse their larvae over long distances.
Poor dispersers — including some isopods, nematode worms and seed shrimps — stayed close to home in the Southern Ocean.
One particularly cosmopolitan group included the foraminifera, or tiny single-celled organisms covered with relatively decorative shells.
Genetic analyses showed that three foraminifera species (Epistominella exigua, Cibicidoides wuellerstorfi and Oridorsalis umbonatus) found in both the Weddell Sea and the Arctic Ocean were nearly identical.
"They literally found some of [the foraminifera] from pole to pole, which is really amazing," Ebbe said.
Time to diversify
In terms of the soaring biodiversity, the scientists suggest organisms in the Antarctic have been around for a long time, giving them time to diversify.
"The Southern Ocean has been like it is pretty much for the last 40 million years, and it has been isolated," Ebbe said. "So the communities have had a long, long time to evolve. In the Arctic, it is much different."
In the geologic past, Antarctica belonged to a giant land mass called Gondwana that straddled the equator.
This land mass, which also included Africa, Australia, India and the tip of South America, started breaking apart more than 100 million years ago.
About 60 million years ago, Antarctica had drifted close to the South Pole, and oceans filled the gaps between Antarctica and Africa and India.
By 40 million years ago, the continent had become completely encircled by water, now called the Southern Ocean.

source of http://www.foxnews.com/ by

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Bone-Crushing Wolves Roamed Alaska During Ice Age

Gray wolves that roamed Alaska during the last ice age were built to tackle prey much larger than themselves and devour them completely—bones and all—a new study says.
The ancient wolves had short snouts, strong jaws, and massive canine teeth unlike those on any wolves today.
But these Alaskan wolves died out along with mastodons, saber-toothed cats, and other big animals at the end of the Pleistocene epoch, about 10,000 years ago.
The finding is based on an analysis of skull and tooth bones collected decades ago from the permafrost and stored today at museums in the U.S. and Canada.
The wolves were specially adapted to a highly competitive life on the vast, icy Alaskan expanses, according to the study, which examined bone shape and DNA and chemical signatures in the bones.
"Certainly, competition would favor those adaptations," said study co-author Blaire Van Valkenburgh, a professor of ecology and evolutionary biology at the University of California, Los Angeles.
She noted that the ancient wolves in Alaska didn't have to compete with larger relatives called dire wolves. This allowed the Alaskan gray wolves to fill a niche unavailable to gray wolf populations farther south.
"If there are advantages, as there generally are, to being stronger, then evolution will proceed in that direction," she said.
The study was published online today in the journal Current Biology.

Big Biters
The ancient Alaskan wolves' short snouts, broad skulls, and large teeth "indicate a specialization for big bite forces," Van Valkenburgh added.
Many of the teeth were also worn down and fractured. This shows that the wolves were eating a lot of bones for nutrition as the animals competed for access to limited prey.
Ice Age carnivores from a cave in Mexico and tar pits in Peru and California also have high rates of tooth wear and fracture, according to the researchers.
"If you killed something, you were likely to have someone come and try to steal it, and so it would behoove you to eat very rapidly and to consume as much of what you killed as possible," Van Valkenburgh said.
Chemical signatures in the wolf bones suggested the animals ate a varied diet of mammoth, musk ox, bison, and horse.
The ancient Alaskan wolves were also genetically distinct from any wolves living today, the authors add.
"If this animal were alive today, it would be classified as a distinct subspecies," Van Valkenburgh said.
Kathleen Lyons is a biologist at Old Dominion University in Norfolk, Virginia, who studies late Pleistocene mammals to understand how current climate change might affect species diversity.
She was not involved in the new research. But she said it is a "great example of how using different lines of evidence can give you a full picture of an extinct animal."
Ice Age Extinction
Like much of their prey and contemporary carnivores, the specialized Alaskan wolves disappeared at the end of the Ice Age.
Scientists have long debated the causes of these extinctions. Some studies link the demise to overhunting by humans. Other studies suggest a warming climate doomed the animals.
And a recent controversial theory says a comet or meteor exploded over northern North America and triggered the die-off.
Study co-author Van Valkenburgh said her study fails to shed light on the cause of the extinction. But "it's most likely that the carnivores went extinct as a result of their prey going extinct."
This kind of effect on Ice Age carnivores highlights a problem for conservation efforts that target a single predator species as the Earth warms and alters landscapes, noted Lyons, of Old Dominion University.
"If you don't preserve the species' habitat and the species' prey species," she said, "then your efforts to try and preserve a species are going to be problematic at best."

source of http://www.nationalgeographic.com/

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The Volcano's

A volcano is an opening, or rupture, in the Earth's surface or crust, which allows hot, molten rock, ash and gases to escape from deep below the surface. Volcanic activity involving the extrusion of rock tends to form mountains or features like mountains over a period of time.

Volcanoes are generally found where tectonic plates pull apart or are coming together. A mid-oceanic ridge, like the Mid-Atlantic Ridge, has examples of volcanoes caused by "divergent tectonic plates" pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by "convergent tectonic plates" coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there is stretching of the Earth's crust and where the crust grows thin (called "non-hotspot intraplate volcanism"), such as in the African Rift Valley, the European Rhine Graben with its Eifel volcanoes, the Wells Gray-Clearwater Volcanic Field and the Rio Grande Rift in North America.

Finally, volcanoes can be caused by "mantle plumes", so-called "hotspots"; these hotspots can occur far from plate boundaries, such as the Hawaiian Islands. Interestingly, hotspot volcanoes are also found elsewhere in the solar system, especially on rocky planets and moons.

Divergent plate boundaries

At the mid-oceanic ridges, two tectonic plates diverge from one another. New oceanic crust is being formed by hot molten rock slowly cooling down and solidifying. In these places, the crust is very thin due to the pull of the tectonic plates. The release of pressure due to the thinning of the crust leads to adiabatic expansion, and the partial melting of the mantle. This melt causes the volcanism and make the new oceanic crust. The main part of the mid-oceanic ridges are at the bottom of the ocean, and most volcanic activity is submarine. Black smokers are a typical example of this kind of volcanic activity. Where the mid-oceanic ridge comes above sea-level, volcanoes like the Hekla on Iceland are formed. Divergent plate boundaries create new seafloor and volcanic islands.

Convergent plate boundaries

Subduction zones, as they are called, are places where two plates, usually an oceanic plate and a continental plate, collide. In this case, the oceanic plate subducts, or submerges under the continental plate forming a deep ocean trench just offshore. The crust is then melted by the heat from the mantle and becomes magma. This is due to the water content lowering the melting temperature. The magma created here tends to be very viscous due to its high silica content, so often does not reach the surface and cools at depth. When it does reach the surface, a volcano is formed. Typical examples for this kind of volcano are the volcanoes in the Pacific Ring of Fire, Mount Etna.

Hotspots

Hotspots are not located on the ridges of tectonic plates, but on top of mantle plumes, where the convection of Earth's mantle creates a column of hot material that rises until it reaches the crust, which tends to be thinner than in other areas of the Earth. The temperature of the plume causes the crust to melt and form pipes, which can vent magma. Because the tectonic plates move whereas the mantle plume remains in the same place, each volcano becomes dormant after a while and a new volcano is then formed as the plate shifts over the hotspot. The Hawaiian Islands are thought to be formed in such a manner, as well as the Snake River Plain, with the Yellowstone Caldera being the current part of the North American plate over the hotspot.

Volcanic features

The most common perception of a volcano is of a conical mountain, spewing lava and poisonous gases from a crater in its top. This describes just one of many types of volcano, and the features of volcanoes are much more complicated. The structure and behavior of volcanoes depends on a number of factors. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater, whereas others present landscape features such as massive plateaus. Vents that issue volcanic material (lava, which is what magma is called once it has broken the surface, and ash) and gases (mainly steam and magmatic gases) can be located anywhere on the landform. Many of these vents give rise to smaller cones such as Puʻu ʻŌʻō on a flank of Hawaii's KīlaueaOther types of volcanoes include cryovolcanos (or ice volcanoes), particularly on some moons of Jupiter, Saturn and Neptune; and mud volcanoes, which are formations often not associated with known magmatic activity. Active mud volcanoes tend to involve temperatures much lower than those of igneous volcanoes, except when a mud volcano is actually a vent of an igneous volcano

Shield volcanoes

Hawaii and Iceland are examples of places where volcanoes extrude huge quantities of basaltic lava that gradually build a wide mountain with a shield-like profile. Their lava flows are generally very hot and very fluid, contributing to long flows. The largest lava shield on Earth, Mauna Loa, rises over 9,000 m from the ocean floor, is 120 km in diameter and forms part of the Big Island of Hawaii, along with other shield volcanoes such as Mauna Kea and Kīlauea. Olympus Mons is the largest shield volcano on Mars, and is the tallest known mountain in the solar system. Smaller versions of shield volcanoes include lava cones, and lava mounds.Quiet eruptions spread out basaltic lava in flat layers. The buildup of these layers form a broad volcano with gently sloping sides called a shield volcano. Examples of shield volcanoes are the Hawaiian Islands.

Cinder cones

Volcanic cones or cinder cones result from eruptions that throw out mostly small pieces of scoria and pyroclastics (both resemble cinders, hence the name of this volcano type) that build up around the vent. These can be relatively short-lived eruptions that produce a cone-shaped hill perhaps 30 to 400 m high. Most cinder cones erupt only once. Cinder cones may form as flank vents on larger volcanoes, or occur on their own. Parícutin in Mexico and Sunset Crater in Arizona are examples of cinder cones.

Stratovolcanoes

Stratovolcanoes are tall conical mountains composed of lava flows and other ejecta in alternate layers, the strata that give rise to the name. Stratovolcanoes are also known as composite volcanoes. Classic examples include Mt. Fuji in Japan, Mount Mayon in the Philippines, and Mount Vesuvius and Stromboli in Italy.

Super volcanoes

A supervolcano is the popular term for a large volcano that usually has a large caldera and can potentially produce devastation on an enormous, sometimes continental, scale. Such eruptions would be able to cause severe cooling of global temperatures for many years afterwards because of the huge volumes of sulfur and ash erupted. They can be the most dangerous type of volcano. Examples include Yellowstone Caldera in Yellowstone National Park, Lake Taupo in New Zealand and Lake Toba in Sumatra, Indonesia. Supervolcanoes are hard to identify centuries later, given the enormous areas they cover. Large igneous provinces are also considered supervolcanoes because of the vast amount of basalt lava erupted.

Submarine volcanoes

Submarine volcanoes are common features on the ocean floor. Some are active and, in shallow water, disclose their presence by blasting steam and rocky debris high above the surface of the sea. Many others lie at such great depths that the tremendous weight of the water above them prevents the explosive release of steam and gases, although they can be detected by hydrophones and discoloration of water because of volcanic gases. Even large submarine eruptions may not disturb the ocean surface. Because of the rapid cooling effect of water as compared to air, and increased buoyancy, submarine volcanoes often form rather steep pillars over their volcanic vents as compared to above-surface volcanos. In due time, they may break the ocean surface as new islands. Pillow lava is a common eruptive product of submarine volcanoes.

Subglacial volcanoes

Subglacial volcanoes develop underneath icecaps. They are made up of flat lava flows atop extensive pillow lavas and palagonite. When the icecap melts, the lavas on the top collapse leaving a flat-topped mountain. Then, the pillow lavas also collapse, giving an angle of 37.5 degrees. These volcanoes are also called table mountains, tuyas or (uncommonly) mobergs. Very good examples of this type of volcano can be seen in Iceland, however, there are also tuyas in British Columbia. The origin of the term comes from Tuya Butte, which is one of the several tuyas in the area of the Tuya River and Tuya Range in northern British Columbia. Tuya Butte was the first such landform analyzed and so its name has entered the geological literature for this kind of volcanic formation. The Tuya Mountains Provincial Park was recently established to protect this unusual landscape, which lies north of Tuya Lake and south of the Jennings River near the boundary with the Yukon Territory.

source of http://www.wikipedia.org/

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