An amount of freshwater almost the size of the Dead Sea has been lost in
parts of the Middle East due to poor management, increased demands for
groundwater and the effects of a 2007 drought, according to a NASA
study.
The study, to be published Friday in Water Resources Research, a journal
of the American Geophysical Union, examined data over seven years from
2003 from a pair of gravity-measuring satellites which is part of NASA's
Gravity Recovery and Climate Experiment or GRACE. Researchers found
freshwater reserves in parts of Turkey, Syria, Iraq and Iran along the
Tigris and Euphrates river basins had lost 117 million acre feet (144
cubic kilometers) of its total stored freshwater, the second fastest
loss of groundwater storage loss after India.
About 60 percent of the loss resulted from pumping underground
reservoirs for ground water, including 1,000 wells in Iraq, and another
fifth was due to impacts of the drought including declining snow packs
and soil drying up. Loss of surface water from lakes and reservoirs
accounted for about another fifth of the decline, the study found.
"This rate of water loss is among the largest liquid freshwater losses
on the continents," the authors wrote in the study, noting the declines
were most obvious after a drought.
The study is the latest evidence of a worsening water crisis in the
Middle East, where demands from growing populations, war and the
worsening effects of climate change are raising the prospect that some
countries could face sever water shortages in the decades to come. Some
like impoverished Yemen blame their water woes on the semi-arid
conditions and the grinding poverty while the oil-rich Gulf faces water
shortages mostly due to the economic boom that has created glistening
cities out of the desert.
A Russian meteor blast that has reportedly injured more than 500
people appears unconnected to the flyby Friday of an asteroid passing
close to Earth, according to astronomers.
The 13-story-size
asteroid, 2012 DA14, passes within 17,100 miles of Earth around 2:24
p.m. ET on Friday before heading off into space. The Russian meteor,
likely about the size of a sports utility vehicle and weighing perhaps
11 tons, struck Russia's Chelyabinsk region, about 900 miles east of
Moscow late Thursday, according to news reports.
"The
Earth travels about a million miles in a day and these are two events
separated by almost 24 hours, so it is unlikely they are connected,"
says asteroid expert Richard Binzel of MIT. Meteors the size of the
Russian one hit Earth every few years, Binzel says, but land near
inhabited places much less often. "We just have the incredible
coincidence of this happening just before the asteroid flies by," Binzel
says.
Further, the Russian meteor landed in the Northern
hemisphere while Asteroid 2012 DA14 is approaching from the direction of
the South Pole, arguing against a connection. The damage in
Chelyabinsk, reportedly broken windows, was caused by the air pressure
wave created when the meteor zoomed into the Earth's atmosphere at
perhaps 33,000 mph.
"It's nice of Nature to give us the full
spectrum of possibilities," Binzel says. Astronomers will want to
recover whatever pieces of the Russian meteor remain for study in the
lab. The space rocks are thought to be leftovers from the era of the
Earth's formation.
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I love it when the Google Doodles do really fun mash-ups, and on today, the day of love, they’ve come up with a doozy.
Not only is today Valentine’s Day, but it’s also the birthday of George
Ferris, inventor of the Ferris Wheel; certainly a place where a fair
share of romance has been exercised.
The doodle is actually a fun little game of spin-the-wheel. There are
two Ferris Wheels, and when you press the heart-shaped button, both
spin until two of the riders are matched up. The riders are all
anthropomorphized (and cute) animals, and based on each pairing we are
presented with an cartoon as to how their date might go. Since there are
8 riders on each wheel, there should be 64 possible outcomes, so it’s
possible to spend some time on this doodle. I haven’t watch them all
yet, but I’m still pulling for the
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Not the best result, from today’s Google Doodle.
If you click through the magnifying glass symbol on the doodle,
you’ll be taken to comprehensive biographical info on George Ferris, and
learn all about this multi-talented civil engineer who invented the
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Via Reuters: The
passage of asteroid 2012 DA14 through the Earth-moon system, is depicted
in this handout image from NASA. On February 15, 2013, an asteroid, 150
feet (45 meters) in diameter will pass close, but safely, by Earth. The
flyby creates a unique opportunity for researchers to observe and learn
more about asteroids.
(NASA)
Early Friday afternoon (2:24 p.m. EST), planet Earth will be buzzed
by an asteroid some 150 feet wide, identified as 2012 DA14, as it
intersects Earth’s orbit just 17,500 miles above our heads.
According to NASA, this is the closest documented encounter of an
asteroid this large (excluding ones which actually smashed into the
Earth). While this might not seem at first even a close miss, on the
cosmic scale of the solar system, it certainly qualifies as a very close
call.
Only last December a somewhat smaller asteroid,
XE54, passed within about 140,000 miles of Earth, and was about as
close to crashing into Earth as an asteroid can without actually doing
so.
(Note: For perspective, a relatively simple calculation shows that
DA14’s closest approach corresponds proportionately to two commercial
aircraft approaching to within about 150 feet of one another. That is
far below FAA requirements for the minimum safe horizontal separation
between airliners - 3 to 10 miles. There is little doubt that coming as
close as 150 feet, which is less than the wingspan of even most
mid-sized commercial passenger planes, is as close one can imagine
without having a disastrous mid-air collision.)
The path of asteroid
2012 DA14's approach to earth is shown in this handout graphic from
NASA obtained by Reuters February 8, 2013. The 50-metre in diameter
asteroid will pass inside the Earth's geosynchronous orbit, reaching its
closest point February 15, 2013. Scientists say there is no danger of
it hitting the earth.
(NASA - REUTERS)
Several recent asteroids have come closer than DA14 but were much
smaller (tens of feet in size). And, when it comes to the consequences
of an Earth-asteroid collision, size really matters.
The smallest asteroids (better described as large rocks) to threaten
Earth most likely would burn up in the atmosphere creating eye-opening
fireballs racing across the sky, possibly with some fragments (referred
to as meteorites) reaching the ground. (Note, by comparison, the
“shooting stars” seen annually in association with meteor showers are
typically pebble sized).
Meteor Crater
(NASA)
An asteroid the size of DA14 is capable of blasting a
crater - with the equivalent of hundreds of Hiroshima atomic bombs –
like the one mile wide hole known as Meteor Crater blasted into the ground 50 thousand years ago in Arizona.
Just 105 years ago (June, 1908) a 300 foot asteroid (or comet
comprised of mostly water ice rather than hard rock) exploded over the Tunguska River in Siberia\
with more power than anything before or since (including thermo-nuclear
hydrogen bombs) in recorded history. Thousands of square miles of
territory were devastated, but the only victims were trees and wild
life.
An equivalent strike today near a metropolitan area would obviously
cause tremendous damage and take a terrible toll on life and societal
infrastructure. However, it’s much more likely that the asteroid would
either produce a big splash (and possible tidal waves) somewhere over
the vastness of earth’s oceans, or create a humongous bang (and possible
earthquakes) over some relatively large and sparsely populated land
mass. In either case, though, the event would not wipe out humanity.
Scientists believe that any space rock larger than about 1 kilometer
(.62 mile) across could cause a global catastrophe. The asteroid which
led to the mass extinction of dinosaurs 75 million years ago was about
10 kilometers (6.2 miles) wide.
“Extinction event” asteroid collisions appear highly improbable (but
possible) on time scales less than millions of years. But objects larger
than about 100 feet like DA14 are believed to strike Earth every few
hundred years. At this time there are no known asteroids of this size on a collision course with Earth for at least 100 years.
What’s of interest and concern, however, is that scientists believe
there are literally tens to hundreds of thousands of objects, mostly
with dimensions in the hundreds of feet, whizzing around in space that
have not yet been discovered. Consider the fact that XE54 was first
observed only the day before its closest approach. Even though it has
been crossing Earth’s orbit about once per year for millennia, DA14 was
discovered less than one year ago.
The
dinosaur footprints were encased in a field jacket, which is much like a
cast that a doctor would place on a broken arm or leg. This field
jacket consisted of many layers of burlap soaked in plaster, with metal
pipes added to act like splints /NASA/GSFC/Rebecca Roth
A chunk of stone bearing dinosaur footprints has been carefully
lifted from the grounds of NASA's Goddard Space Flight Center in
Greenbelt, Md., scientists report.
The dino tracks,
thought to have been left by three separate beasts more than 100
million years ago, were discovered by amateur paleontologist Ray
Stanford in August 2012.
The feature that first caught Stanford's eye was a dinner-plate-sized footprint of a nodosaur, a tanklike dinosaur
studded with bony protuberances that roamed the area about 110 million
years ago during the Cretaceous period (the period from 145 million to
65 million years ago that was the end of the Mesozoic Era). This
particular lumbering leaf-eater must have been moving quickly across the
prehistoric mud, as its heel did not sink deeply into the ground.
A closer look at the site revealed two more prints. Stephen Godfrey, a
paleontology curator at the Calvert Marine Museum, who was contracted to
preserve the find, said he suspects one was left by an ornithopod,
possibly from the iguanodontid family, which were large vegetarian dinosaurs
with birdlike, three-toed feet that walked on its hind legs. Another
smaller footprint found superimposed over the nodosaur track is thought
to be from a baby nodosaur, perhaps trying to catch up to its parent,
according to a statement from NASA.
The stretch of ground containing the prints measured about 7 feet long
and 3 feet across at its widest point. After making a silicon-rubber
cast of the dino tracks, the team covered the find in plaster-soaked
burlap, much like an orthopedic cast, to reinforce the slab and protect
it from damage during the big move. Altogether, the stone slab, the
protective jacket and surrounding soil weighed about 3,000 pounds, and
it was successfully pulled out of the ground last month.
For now, the prints are being stored at Goddard until further
scientific study is possible. The wonder of the discovery has not been
lost on space scientists at Goddard, who often find themselves studying
starlight as old as the dinosaurs.
"One of the amazing aspects
of this find is that some of the starlight now seen in the night sky by
astronomers was created in far-distant galaxies when these dinosaurs
were walking on mud flats in Cretaceous Maryland where Goddard is now
located," Jim Garvin, Goddard's chief scientist, said in a statement.
"That starlight (from within the Virgo Supercluster) is only now
reaching Earth after having traveled through deep space for 100 million
years."
