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The Chandler wobble is a small variation in Earth's axis of rotation, discovered by American astronomer Seth Carlo Chandler in 1891. It amounts to 0.7 arcseconds over a period of 433 days. In other words, Earth's poles move in an irregular circle of 3 to 15 metres in diameter, in an oscillation. This is in addition to the precession of the equinoxes, a larger oscillation which takes over 25,000 years to complete. This article is about Earth as a planet. ...
The Earths rotation is the rotation of the solid earth around its own axis, which is called Earths axis or rotation axis. ...
An astronomer or astrophysicist is a person whose area of interest is astronomy or astrophysics. ...
Seth Carlo Chandler, Jr. ...
Year 1891 (MDCCCXCI) was a common year starting on Thursday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Saturday of the 12-day slower Julian calendar). ...
A second of arc or arcsecond is a unit of angular measurement which comprises one-sixtieth of an arcminute, or 1/3600 of a degree of arc or 1/1296000 ≈ 7. ...
Oscillation is the variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. ...
Precession of the equinoxes refers to the precession of the Earths axis of rotation. ...
The wobble's diameter has varied since discovery, reaching its most extreme range recorded to date in 1910. The cause is unknown: barring any external force, the wobble should have eventually subsided. Originally it was believed that the wobble was caused by seasonal weather fluctuations causing shifts in atmospheric mass distribution, or possible geophysical movement beneath Earth's crust. On 18 July 2000, however, the Jet Propulsion Laboratory announced that "the principal cause of the Chandler wobble is fluctuating pressure on the bottom of the ocean, caused by temperature and salinity changes and wind-driven changes in the circulation of the oceans."[1] Year 1910 (MCMX) was a common year starting on Saturday (link will display calendar) of the Gregorian calendar (or a common year starting on Friday [1] of the 13-day-slower Julian calendar). ...
This article or section is in need of attention from an expert on the subject. ...
For the geological process, see Weathering or Erosion. ...
Mass distribution is a term used in physics, geosciences and mechanics and describes the spatial distribution of mass within a solid body. ...
is the 199th day of the year (200th in leap years) in the Gregorian calendar. ...
Year 2000 (MM) was a leap year starting on Saturday (link will display full 2000 Gregorian calendar). ...
For the singer/songwriter, see Jon Peter Lewis. ...
Animated map exhibiting the worlds oceanic waters. ...
For other uses, see Temperature (disambiguation). ...
Annual mean sea surface salinity for the World Ocean. ...
For other uses, see Wind (disambiguation). ...
The Chandler wobble is a factor considered by satellite navigation systems (especially military systems). It is also claimed to be the cause of major tectonic activity, including earthquakes, volcanism, El Niño, and global warming phenomena, however there is no actual data which supports such a claim. For other uses, see Satellite (disambiguation). ...
Table of geography, hydrography, and navigation, from the 1728 Cyclopaedia. ...
The tectonic plates of the world were mapped in the second half of the 20th century. ...
An earthquake is the result of a sudden release of stored energy in the Earths crust that creates seismic waves. ...
This article is about volcanoes in geology. ...
Chart of ocean surface temperature anomaly [°C] during the last strong El Niño in December 1997 El Niño and La Niña (also written in English as El Nino and La Nina) are major temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean. ...
Global warming refers to the increase in the average temperature of the Earths near-surface air and oceans in recent decades and its projected continuation. ...
During the first hour of the national radio broadcast of Coast to Coast AM on January 28, 2006, Lloyd Stewart Carpenter reported that the Chandler wobble had stopped (i.e. its amplitude had reduced to zero) and that it could be a harbinger of a catastrophic pole shift. In fact there was a near six week period in which a significant pause occurred. This was first noted by the International Earth Rotation Service on or about January 5, 2006 as the path of the wobble, usually a widening or tightening spiral depending on the depth of the cycle, made a 90° departure from its predicted track. It proceeded to cease any substantial movement until on or about February 11th when the wobble appeared to begin tracing a path back toward its normal route. This anomaly has been of great interest in gaining a better understanding, but it is not yet known if this has or will cause any catastrophic changes in the overall rotation axis of the planet.[citation needed] Coast to Coast AM is a late-night syndicated radio talk show in the United States which deals with a variety of topics, but most frequently ones that relate either to the paranormal, or to alleged conspiracies. ...
is the 28th day of the year in the Gregorian calendar. ...
Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ...
A pole shift theory is a hypothesis that the axis of rotation of a planet has not always been at its present-day locations or that the axis will not persist there; in other words, that its physical poles had been or will be shifted. ...
The International Earth Rotation Service (IERS) is the body responsible for maintaining global time and reference frame standards, notably through its Earth Orientation Paramater (EOP) and International Celestial Reference System (ICRS) groups. ...
The Chandler wobble changes over time, with U.S. Navy data over the past several years showing the wobble has diminished as of mid-late 2005. However, this is likely transient, as the wobble has increased and decreased many times in the past and will likely do so a great many more times in the future. USN redirects here. ...
The Chandler wobble is a small variation in Earth's axis of rotation, discovered by American astronomer Seth Carlo Chandler in 1891. It amounts to 0.7 arcseconds over a period of 433 days. In other words, Earth's poles move in an irregular circle of 3 to 15 metres in diameter, in an oscillation. This is in addition to the precession of the equinoxes, a larger oscillation which takes over 25,000 years to complete.
The wobble's diameter has varied since discovery, reaching its most extreme range recorded to date in 1910. The cause is unknown: barring any external force, the wobble should have eventually subsided. Originally it was believed that the wobble was caused by seasonal weather fluctuations causing shifts in atmospheric mass distribution, or possible geophysical movement beneath Earth's crust. On 18 July 2000, however, the Jet Propulsion Laboratory announced that "the principal cause of the Chandler wobble is fluctuating pressure on the bottom of the ocean, caused by temperature and salinity changes and wind-driven changes in the circulation of the oceans."
The Chandler wobble is a factor considered by satellite navigation systems (especially military systems). It is also claimed to be the cause of major tectonic activity, including earthquakes, volcanism, El Niño, and global warming phenomena, however there is no actual data which supports such a claim.
During the first hour of the national radio broadcast of Coast to Coast AM on January 28, 2006, Lloyd Stewart Carpenter reported that the Chandler wobble had stopped (i.e. its amplitude had reduced to zero) and that it could be a harbinger of a catastrophic pole shift. In fact there was a near six week period in which a significant pause occurred. This was first noted by the International Earth Rotation Service on or about January 5, 2006 as the path of the wobble, usually a widening or tightening spiral depending on the depth of the cycle, made a 90° departure from its predicted track. It proceeded to cease any substantial movement until on or about February 11th when the wobble appeared to begin tracing a path back toward its normal route. This anomaly has been of great interest in gaining a better understanding, but it is not yet known if this has or will cause any catastrophic changes in the overall rotation axis of the plane.
The Chandler wobble changes over time, with U.S. Navy data over the past several years showing the wobble has diminished as of mid-late 2005. However, this is likely transient, as the wobble has increased and decreased many times in the past and will likely do so a great many more times in the future.
References
- ^ A Mystery of Earth's Wobble Solved, Jet Propulsion Laboratory press release announcing cause of the Chandler wobble, July 18, 2000
- Carter, B, and M.S, Carter, 2003, "Latitude, How American Astronomers Solved the Mystery of Variation", Naval Institute Press, Annapolis.
- Lambeck, K., 1980, The Earth's Variable Rotation: Geophysical Causes and Consequences, Cambridge University Press, London.
- Munk W. H. and MacDonald, G. J. F., 1960, The Rotation of the Earth, Cambridge University Press, London.
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