Earth's Mystery Wobble
April 29th 2011 00:29
Category: Planets
Earth image by NASA
Our Earth spins very rapidly on it’s axis around 1675 km/h, apart for the spinning motion the Earth has a slight wobble. If you picture a child’s spinning top as it begins to slow it wobbles.
The Earth has always had a case of the wobbles, some lasting a few minutes some lasting many millions of years. When a wobble occurs it is enough to cause the Earth to slow down we are talking in the Micro second range.
A mystery developed some years ago as to why the position of the Earth’s poles move or wobble by as much as 8 meters. Since the 1960s when lasers were perfected they were used to measure accurately the distance between the Earth and the Moon. With the aid of satellite GPS any discrepancy here on Earth can be measured down to the nearest centimeter.
The notion of the Earth wobbling goes back to 1891 when astronomer Seth Chandler noticed that a “wobble” occurred in cycles of 433-days. No one had an answer to why this phenomenon was happening. We humans won’t notice any wobble apart from the odd earthquake, earthquakes are caused by different factors such as moving plate tectonics.
The Earth’s wobble is thought to be caused by a chain of events such as changes in the world’s ocean pressures, wind including changing ocean currents.
The changing sea pressures is enough to cause the Earth’s crust to under go ‘waves ‘of compression enough to introduce the wobble. The earth vibrates at certain resonant frequencies, any substantial changes in sea pressures or any other associated factors can disturb the Earth’s natural resonant frequencies.
The Earth has more than one wobble. There is an annual wobble introduced by the Sun’s gravitational pull on the Earth. The Moon also influences changes on the Earth causing the ocean’s tides to rise and fall.
The daily rotation of the planet creates a bulge at the equator. The combined gravity of the Sun and Moon tends to pull this bulge back into place. The Earth compensates for the pull of the Sun and Moon while completing it’s annual orbit around our Sun.
The Earth is tilted at an angle of 23.5 degrees, the axis moves in a cone shaped pattern very slowly over a period of 14,000 years.
Currently our North celestial pole is pointing the star Polaris a in another 14,000 years it will be pointing at the star Vega.
It so happens that the Sun together with the solar system is heading in the direction of the star Vega.
If you happen to be walking and fall suddenly, it may be attributed to the Earth wobbling, but it most likely to be the effects of too much “merriment’
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Comment by S.L.
The Political Brief
The first I ever heard about the wobble of the Earth was in Graham Hancocks book, "Fingerprints of the Gods". It's amazing how the Earth undergoes changes without any input from humanity. Are you listening, Algore?
Comment by CarlCan
Astroearth
Camera Sense
I have a lovely Persian cat who loves being under my feet and at time I mistakenly think it is my other missing slipper LOL.
It is mind boggling to think that our Earth has a ‘soul’ and is capable of undergoing subtle changes, you are right, politicians take note.