Scientists using NASA Earth water migrates satellite data have solved two puzzles about the rotation of the Earth wobble & mdash; one is new, and the other for more than a century ago. This research may help us to enhance understanding of past and future climate. Although the globe forever in the north and south poles around its axis of rotation is firmly connected to the turn, but the real rotation of the earth would wobble. Earth's rotation axis around the pole slowly wavering; since observations furthest offset distance pole 37 feet (12 meters). The swing does not affect our daily lives, but if you want GPS, Earth observation satellites and ground-based observatories to obtain accurate results, it is necessary to pay attention to them.
Earth around the poles is not always connected to the rotation axis in the rotation. Over time, it will not be regular swing, most of the 20th century, the rotation axis is moving toward the direction of North America (green arrow). Due to changes in the quality of water on Earth, causing its direction changed dramatically.
Source: NASA / JPL-Caltech
Around the year 2000, the Earth's rotation axis is shifted in the direction of Canada (green arrow, left panel). Jet Propulsion Laboratory (JPL) scientists calculated the water quality in different regions (Figure) impact (right) on the axis of rotation stretch eastward shift and the rate of change.
Source: NASA / JPL-Caltech
Illustrated as terrestrial water quality and the Earth's rotation axis East - West relations between swing. Eurasian water loss will generally eastward swing axis of rotation (above), and Eurasia will increase the amount of water pushed westward rotation axis (below).
Source: NASA / JPL-Caltech
Posted in the "scientific progress" a paper, Pasadena, Calif. NASA's Jet Propulsion Laboratory Surendra Adhikari and Erik Ivins study how the Earth's water is migrating to promote rotation of the earth wobble. Earlier studies have accurately pointed out the many links the Earth's surface or internal movements and shaking of the earth between the way. For example, the mantle is still re-adaptation after the last Ice Age in North America the loss of ice, the water quality of the North American continent following the spin axis to reduce the annual rate of a few inches to pull Canada. However, there are some mobile remains unexplained.
In the year 2000, the Earth's rotation axis suddenly swerved to the east, and at twice the speed of the move before, each year about 7 inches (17 cm). & Ldquo; it is no longer moved to Hudson Bay, toward the British Isles. & Rdquo; Adhikari said. & Ldquo; It was a very big swing. & Rdquo; Adhikari and Ivins began to explain this unexpected change.
Scientists have suggested that due to the rapid melting of ice sheets in Greenland and Antarctica and the loss of water quality may cause the spin axis is the eastward deflection reasons. NASA / German Space Center Gravity Recovery and Climate Experiment (German Aerospace Center Gravity Recovery and Climate Experiment, GRACE) satellites are given monthly change record of the Earth's mass distribution, Jet Propulsion Laboratory scientists use these data to assess this term speculation. These changes largely by the accumulation of snow, groundwater depletion, etc. These daily flow caused by movement. They calculated between 2003 and 2015, the water on the earth had lost much during the cycle between land and sea and in the inflow involved in the push and pull of Earth's axis of rotation.
Adhikari and Ivins results show that only changes in Greenland and not enough to produce the spin axis can pull huge energy shift happened so far. In the southern hemisphere, the loss of glaciers in western Antarctica formed a pulling force, while increasing the glaciers in the eastern side of the Antarctic continent, driven Greenland from the north face in the same direction of the pull of the Earth's axis of rotation, but the impact of these two forces together still not enough to explain the acceleration and direction of the axis of rotation offset changes. East of Greenland must have a force is applied to the spin axis of the additional tension.
The researchers found the answer in Eurasia. & Ldquo; The main reason is the lack of water Eurasia: in the Indian subcontinent and the Caspian region, & rdquo; Adhikari said.
This makes a very unexpected discovery. Consumption and depletion of aquifers in the region resulting in the loss of the water, but the water loss is far less dramatic change in ice.
So why there is a relatively small loss of such a huge impact? The researchers say this is because of the rotation axis 45 degrees latitude near very sensitive to changes in both hemispheres are the same. & Ldquo; the theory of a rotating object a good explanation of this point, & rdquo; Adhikari explained. & Ldquo; This is why such changes on the Indian subcontinent is so important. & Rdquo;
New insight on an old swing
Puzzle to answer in this new process, the researchers accidentally thought of a very promising new questions to answer another ancient method. Earth's rotation, there is a special swing from 1899 onwards observation puzzled scientists. Every 6-14 years, will be in the rotation axis direction on the east or west of the original offset swing 20-60 inches (0.5 to 1.5 meters). & Ldquo; although after numerous theoretical studies and modeling, this mysterious swing still did not find a reasonable explanation. & Rdquo; Adhikari said.
Scientists will GRACE case of the spin axis swing of things made the offer during a chart data and inland water, and the same time changing the chart were compared, JPL scientists found a striking resemblance. Changes in the polar ice and the swing seems irrelevant, only the amount of water on the land changes will affect the swing. For example, Eurasia drought years is a corresponding swing eastward, and westward wet year corresponds swing.
When the researchers will vary terrestrial water mass GRACE2002 April to March 2015 during observations substituted into pole position prediction equations of classical physics, they found that the observed results and is very close to the swing of things. & Ldquo; This is not only far from the simple correlation, & rdquo; co-author Ivins said. & Ldquo; We have analyzed the reasons out. & Rdquo;
The findings raise the possibility that this 115-year period of the recorded data of Earth's rotation axis swing of things, may be used as an excellent record terrestrial water change. & Ldquo; they can tell us some of the past climatic conditions & mdash; dry and wet degree if there is enhanced over time, as well as the specific area, & rdquo; Adhikari said.
The shift (the earth pole shift) the history of not only global broad sense, but also extremely accurate. & Rdquo; Ivins said. & Ldquo; Our research shows that this group of valuable legacy data can be used to calculate the changes in the ice sheets on land and water. & Rdquo;
GRACE is a NASA and the German Aerospace Center (DLR), the German Earth Science Research Center (GFZ), and cooperation tasks University of Texas at Austin's. For more information about this task, please click:
NASA is using its superiority in space to improve our understanding of the survival of the planet depend Fengyun understanding, improved quality of life while protecting the future. NASA has opened up new ways to take advantage of long-term data record to observe and study the natural systems on Earth interrelated. But also free to share this valuable information to researchers and research institutions around the world, in order to obtain a new perspective on the Earth change.
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