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Mars Base

Santorini Bulges as Magma Balloons Underneath - 0 views

news.nationalgeographic.com/...lava-santorini-volcano-science

scibyte63 Santorini

shared by Mars Base on 13 Sep 12 - No Cached
  • Santorini locals began to suspect last year that something was afoot with the volcano under their Greek island group
  • Wine glasses occasionally vibrated and clinked in cafes, suggesting tiny tremors, and tour guides smelled strange gasses.
  • satellite radar technology has revealed the source of the symptoms. A rush of molten rock swelled the magma chamber under the volcano by some 13 to 26 million cubic yards (10 to 20 million cubic meters)—about 15 times the volume of London's Olympic Stadium—between January 2011 and April 2012
  • ...17 more annotations...
  • even forced parts of the island's surface to rise upward and outward by 3 to 5.5 inches (8 to 14 centimeters).
  • volcano has been quiet for 60 years
  • recent events don't indicate an imminent eruption
  • the earthquake activity and the rate of bulging have both slowed right down in the last few months, it doesn't look as though the volcano is about to start to erupt, and it is quite likely that it could remain quiet for another few years or decades.
  • don't know enough about the lifecycle of large volcanoes in between eruptions to be certain
  • beginning in the January 2011 data, more than a thousand small quakes, most of them imperceptible
  • confirmed a subtle rise in Santorini's surface level with satellite radar images and GPS receivers
  • Catastrophic eruptions on Santorini, which produce mostly pumice rather than lava, appear to occur here about 20,000 years apart
  • The last one, in 1950, oozed enough lava to cover a few tennis courts
  • Despite its relative quiet, Santorini is an ideal location to learn more about processes like the magma chamber's rapid inflation
  • While satellite evidence of swelling magma chambers has rarely been available for an active volcano, the processes the data represent may not be all that unusual
  • some large volcanoes like Santorini and Yellowstone spend hundreds or thousands of years in a state of what you'd call dormancy
  • they'll often have these little restless patches
  • These types of phenomena are likely to be common, but you need the right instruments and technology to detect what are usually rather small changes in behavior."
  • we aren't any closer to knowing if, or when, the next lava eruption might happen
  • likening the recent swelling to someone blowing a big breath into an invisible balloon.
  • don't know how small or big the balloon is, and we don't know whether just one more breath will be enough for it to pop or not
Mars Base

Jupiter Moon's Buried Lakes Evoke Antarctica | Jupiter Moon Europa | Subsurface Lakes P... - 0 views

www.space.com/arth-antarctica-analogues.html

scibyte22 Europa

shared by Mars Base on 17 Nov 11 - No Cached
  • Patches of broken ice unique to the moon have puzzled scientists for over a decade
  • Some have argued they are signs of a subterranean ocean breaking through, while others believe that the crust is too thick for the water to pierce
  • studies of ice formations in Antarctica and Iceland have provided clues to the creation of these puzzling features
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  • , a combination of these elements could very well be at work on Jupiter's moon
  • "It looks like crushed ice,
  • In Iceland, volcanoes lay beneath the ice. Their heat melts the base of glaciers and ice sheets, causing the surface to buckle in on itself and allowing stress fractures to form
  • there's no evidence for volcanoes on Europa, and the makeup of the ice is likely different from Earth'
  • irregular areas contain domes and iceberglike blocks that no theoretical models have been able to replicate
  • "On Earth, it is the volcano [melting the ice]," Schmidt said. "On Europa, it is the warm ice plume coming up from below."
  • estimated that it contained as much water as all of the North America's Great Lakes combined, about 1.5 miles (3 kilometers) beneath the surface.
  • One such lake
  • several liquid lakes are likely to exist near the surface today
  • The material cycled into the ocean via these lakes may make Europa's ocean even more habitable than previously imagined
  • The lakes may even be habitats themselves
Mars Base

News in Brief: World's largest volcano lurks beneath Pacific Ocean | Earth | Science News - 0 views

www.sciencenews.org/...no_lurks_beneath_Pacific_Ocean

scibyte101 volcano

shared by Mars Base on 07 Sep 13 - No Cached
  • The most massive volcano in the world, with a footprint the size of New Mexico, crouches in the dark depths of the western Pacific Ocean
  • hollowed peak lying beneath 2 kilometers of water
  • a basaltic mound, may rival the largest known volcano in the solar system: Mars’ Olympus Mons
  • ...4 more annotations...
  • A team led by oceanographer
  • bounced sound waves off the deep-sea mountain to measure its size
  • Tamu Massif forms a broad, rounded dome rising 4 kilometers from the seafloor and stretching 450 by 650 kilometers across
  • Core samples that the researchers extracted from the volcano’s slopes showed that, during its prime 145 million years ago, the ancient mound spewed lava sheets 23 meters thick.
Mars Base

Magma Boils Beneath Antarctic Ice | Science/AAAS | News - 0 views

news.sciencemag.org/...ma-boils-beneath-antarctic-ice

scibyte110

shared by Mars Base on 19 Nov 13 - No Cached
  • Marie Byrd Land is a desolate region of Antarctica buried deep beneath the West Antarctic Ice Sheet
  • Historic eruptions have punctured the ice sheet, creating a chain of volcanoes amid the ice
  • researchers have shown that molten rock still stirs deep underground
  • ...24 more annotations...
  • Only the largest eruptions could melt all the ice above them and poke through to the surface, but even smaller eruptions could potentially cause global sea level to rise, although no one knows how big the rise might be
  • The crust is thinned by the West Antarctic Rift System, a series of giant rift valleys beneath the ice sheet
  • erupted lava from underground magma chambers has burst through the ice repeatedly over geological history as the plates moved over the top
  • No one knew whether magma was still stirring
  • until seismic monitoring stations were installed on the ice between 2007 and 2010.
  • Researchers built the stations to study the shifting crustal blocks of the West Antarctic Rift System
  • But seismologist
  • found another use
  • They noticed a series of small earthquakes, mainly occurring during two “seismic swarms” in January and February 2010 and March 2011
  • These earthquakes were unusual: The ground was shaking much more slowly during the quakes than one would expect from the plates grinding against each other
  • looked at two different types of waves that come in—the P wave, which is the primary wave, and the S wave, which is the secondary wave
  • calculations revealed that the waves had come from 25 to 40 kilometers below Earth's surface and were centered around a point
  • approximately the point the volcanic activity should have reached if it had continued the linear trend of volcanoes to the south
  • The exact cause of these deep quakes is not understood, but they are thought to result from the movement of magma deep below active or soon-to-be active volcanoes
  • They found that the area showed a slightly higher magnetic field than the surrounding area and that there was a bump in the crust—common signals of magmatic activity
  • Radar mapping also indicated a layer of volcanic ash embedded in the ice
  • probably
  • from an eruption of Mount Waesche about 8000 years ago—very recent geological history
  • There is no evidence of an actual eruption since then, but, because magma is still moving deep under the Earth, an eruption could occur at any time
  • The current center of volcanic activity is covered by at least 1 kilometer of ice, and it would take an exceptionally large eruption to melt all this
  • But an eruption could make its presence felt in subtler ways. As fresh snow adds to their own mass, ice sheets flow downward into the sea
  • melting the base of the ice sheet, an eruption could speed up this flow, potentially raising the level of the ocean. No one knows how significant such a rise might be
  • Any effect on the ice sheet above, and thus any effect on the oceans, would probably be quite small
  • a proper study is needed to find out how significant volcanic activity could be to future sea levels
Mars Base

First Ever Geologic Map of Io: 425 Volcanoes, No Craters - 0 views

www.universetoday.com/...of-io-425-volcanoes-no-craters

scibyte39 Io jupiter MarMedia

shared by Mars Base on 21 Mar 12 - No Cached
  • One of the reasons for making this map was to create a tool for continuing scientific studies of Io
  • target planning of Io observations on future missions to the Jupiter system
  • 19 different surface material types
  • ...6 more annotations...
  • mapping identified 425 paterae, or individual volcanic centers.
  • determined that most of the active hot spots occur in paterae, which cover less than 3 percent of Io’s surface
  • one feature you won’t see on the geologic map: impact craters
  • testifying to Io’s very active volcanic resurfacing
  • Io is so volcanically active — more than 25 times more volcanically active than Earth
  • most of the long-term surface changes resulting from volcanism are restricted to less than 15 percent of the surface
Mars Base

Discovery of historical photos sheds light on Greenland ice loss - 0 views

phys.org/...wledge-glaciers-greenland.html

scibyte49 GlobalWarming

shared by Mars Base on 30 May 12 - No Cached
  • Researchers at the National Survey and Cadastre of Denmark
  • had been storing the glass plates since explorer Knud Rasmussen's expedition to the southeast coast of Greenland in the early 1930s.
  • Ohio State University researchers and colleagues in Denmark describe how they analyzed ice loss in the region by comparing the images on the plates to aerial photographs and satellite images taken from World War II to today.
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  • imagery shows that glaciers in the region were melting even faster in the 1930s than they are today
  • A brief cooling period starting in the mid-20th century allowed new ice to form, and then the melting began to accelerate again in the 2000s.
  • we now have a detailed historical analogue for more recent glacier loss
  • confirmed that glaciers are very sensitive indicators of climate."
  • cleaning up in the basement and had found some old glass plates with glaciers on them
  • The reason the plates were forgotten was that they were recorded for mapping, and once the map was produced they didn't have much value."
  • They contained aerial photographs of land, sea and glaciers in the southeast region of the country, along with travel photos of Rasmussen's team.
  • researchers digitized all the old images and used software to look for differences in the shape of the southeast Greenland coastline where the ice meets the Atlantic Ocean
  • calculated the distance the ice front moved in each time period.
  • Over the 80 years, two events stand out: glacial retreats from 1933-1934 and 2000-2010
  • 1930s, fewer glaciers were melting than are today, and most of those that were melting were land-terminating glaciers, meaning that they did not contact the sea.
  • were melting retreated an average of 20 meters per year - the fastest retreating at 374 meters per year
  • Fifty-five percent of the glaciers in the study had similar or higher retreat rates during the 1930s than they do today.
  • more glaciers in southeast Greenland are retreating today, and the average ice loss is 50 meters per year. That's because a few glaciers with very fast melting rates - including one retreating at 887 meters per year - boost the overall average.
  • From 1943-1972, southeast Greenland cooled - probably due to sulfur pollution, which reflects sunlight away from the earth.
  • Sulfur dioxide is a poisonous gas produced by volcanoes and industrial processes. It has been tied to serious health problems and death, and is also the main ingredient in acid rain.
  • deadly pollution caused the climate to cool, but rather that the brief cooling allowed researchers to see how Greenland ice responded to the changing climate.
  • glaciers responded to the cooling more rapidly than researchers had seen in earlier studies
  • Sixty percent of the glaciers advanced during that time, while 12 percent were stationary
  • now that the warming has resumed, the glacial retreat is dominated by marine-terminating outlet glaciers, the melting of which contributes to sea level rise.
  • we see that the mid-century cooling stabilized the glaciers," Box said. "That suggests that if we want to stabilize today's accelerating ice loss, we need to see a little cooling of our own."
Mars Base

Supervolcanoes Rocked Early Mars - 0 views

news.nationalgeographic.com/...rs-super-volcano-space-ancient

scibyte105 ViewerFeedback Google+

shared by Mars Base on 05 Oct 13 - No Cached
  • Massive "supervolcanoes" erupted across the northern face of Mars some 3.7 billion years ago, planetary scientists suggest
  • he eruptions likely blasted lava, sulfur, and ash across the red planet, altering its atmosphere and surface.
Mars Base

May 18 - Today in Science History - Scientists born on May 18th, died, and events - 0 views

todayinsci.com/5_18.htm

scibyte130 LookingBackMay

shared by Mars Base on 11 May 14 - No Cached
  • Mount St. Helens
  • In 1980, following a weeklong series of earthquakes and smaller explosions of ash and smoke, the long-dormant Mount St. Helens volcano erupted in Washington state, U.S., hurling ash 15,000 feet into the air and setting off mudslides and avalanches. The eruptions caused minimal damage in the sparsely populated area, but about 400 people - mostly loggers and forest rangers - were evacuated. The explosion was characterized as the equivalent of 27,000 atomic bombs. The cloud of ash eventually circled the globe
Mars Base

May 30 - Today in Science History - Scientists born on May 30th, died, and events - 0 views

www.todayinsci.com/...5_30.htm

scibyte132 LookingBackMay

shared by Mars Base on 25 May 14 - No Cached
  • Mars probe
  • In 1971, the U.S. Mars space probe Mariner 9 blasted off from Cape Kennedy, Florida. It carried cameras, infrared spectrometer and radiometer, ultraviolet spectrometer, radio occultation and celestial mechanics instruments. On 13 Nov 1971, it entered orbit as the first artificial satellite of Mars. After waiting for a month-long planet-wide dust storm to clear, it began compiling a global mosaic of high-quality images for 100% of the Martian surface. The photos showed gigantic volcanoes, a grand canyon stretching 4,800 kilometers (3,000 miles) and relics of ancient riverbeds that were carved in the landscape of this seemingly dry and dusty planet. It also sent the first closeup pictures of the two Martian moons, Phobos and Deimos.
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