© NASASatellite image of Antarctica's Dry Valleys.
The greatest desert on Earth is not blazing hot but freezing cold: the icy wastes of Antarctica.
Now scientists find the speed at which sand dunes drift across the ground of this frigid desert has tripled in the past 40 years - a finding that could shed light on everything from the planet's warming climate to deserts on Mars.
Antarctica is not just the
coldest of Earth's continents, but the driest and windiest. The scant areas that are free of snow and ice make up less than 0.4 percent of the continental land mass. In places there, the wind has built sand dunes.
The most extensive dune field is found in Victoria Valley, one of the McMurdo Dry Valleys, and it holds Antarctica's largest dune, 230 feet (70 meters) high and more than 650 feet (200 m) wide.
Climate cluesAntarctica has been described as one of the most climatically
sensitive ecosystems on Earth, meaning that one can look at changes there to help understand global trends in climate, explained geologist Charlie Bristow at Birkbeck College University of London. As such, evidence of changes "in the rates of physical processes that are climatically sensitive, such as the migration of sand dunes, is important," Bristow told OurAmazingPlanet.
Scientists also are investigating Antarctic dunes to learn more about the past; such cold-climate dunes covered large areas of northwest Europe at the end of the last Ice Age.
In addition, Antarctic dunes could shed light on sand dunes on planets such as Mars, which is also very cold, dry and free of surface vegetation.
Bristow and his colleagues used ground-penetrating radar to image the layers of sand in the Victoria Valley dunes, showing how they built up over time. The researchers next used optically stimulated luminescence, a method that determines when objects were last exposed to daylight, to figure out when specific layers of sand were buried. This process wasn't always easy.
"One of the problems in the field was the wind, which rises during the day and becomes quite a problem when the sand starts to blow," Bristow said.
Five feet a yearThe scientists found these dunes apparently are now migrating far more quickly across the surface than they have for centuries. The average rate that dunes there have migrated in the past 40 years is 5 feet (1.5 m) annually. The average annual rate over the approximately 1,300 years before then was 1.5 feet (0.45 m).
The researchers noted that this speed-up coincides with the modern
rise in levels of atmospheric carbon dioxide, which traps heat from the sun and helps warm the planet. A warming climate in the Dry Valleys would loosen the ice cementing the dune sands in place, helping them to migrate faster.
In the future, the researchers would like to drill into the valley's larger dunes to get longer records from older deposits. They detailed their findings online Aug. 5 in the journal
Geology.
"The researchers noted that this speed-up coincides with the modern rise in levels of atmospheric carbon dioxide...."
Whatever the study, in seemingly all fields of natural science, it seems that finding a link to anthropogenic global warming allegedly caused by the rising level of CO2 in the atmosphere has become de rigueur for getting funding, so of course such specious reasoning must always be mentioned somehow in all the press releases and scientific reports published in reputable journals.
Nevermind that the current level of CO2 in the atmosphere is merely 350ppm (parts per million), which is 0.035 percent. That's right, 3.5 hundredths of one percent. Water vapor in the atmosphere is orders of magnitude higher, and has a correspondingly larger influence on both weather and climate. And the two-thirds of the Earth is covered by water. The willful innumeracy of the climate change scammers is so obvious, and so self-serving, that it should be seen as criminal.
Those who promote the fear of non-existent anthropogenic global warming to advance their schemes of global enslavement in some fascist new world order ought to be hunted down in the streets and tarred and feathered, hung from the nearest tree (ironically enough).
Science is deeply corrupted by politics and religion - the Big Bang theory in cosmology comes to mind - which degrades its utility to help guide us all in making wise policy decisions in many important areas. One fears this will remain the case as long as psychopaths rule the world. It's quite tragic, because this was a very nice planet.