http://hpiers.obspm.fr/The Paris Observatory is hosting two components of
The International Earth Rotation Service: the Earth Orientation and International Celestial Reference Frames Centers, in close association with the International Terrestrial Reference Frame Center, hosted in Institut Géographique National, located in Ile de France. The International Earth Rotation Service (IERS) is an interdisciplinary service that maintains key connections between astronomy, geodesy and geophysics. He provide:
Celestial reference frame
Terrestrial reference frame
Earth orientation data
Permanent information on the Earth fluid layer
IERS Conventions
The service now accomplishes its missions through various components: a Central Bureau, Techniques Centers, Product Centers and Combination Research Centers.
Two online webcams of Foucalt pendulums that currently track the Earth's wobble.
www.physics.colostate.edu www.pendelcam.kip.uni-heidelberg.deHow does a pendulum demonstrate the Earth’s rotation?
As you watch the pendulum for just a short time, it will appear to be moving clockwise across the mosaic map on the floor.
But, since there is no outside force making the pendulum rotate as it swings, and no other outside force interrupting the swing, it must be the floor itself that is rotating, while the path of the pendulum’s swing remains constant.
The apparent rotation of a Foucault pendulum is affected by two kinds of motion: twisting and travelling. Twisting is circular motion directly on an axis. Travelling is circular motion around an axis.
To help understand this, consider two Foucault pendulums, one placed directly on the north pole and the other placed directly on the equator. At the north pole, the pendulum’s swing rotates in a complete circle every 24 hours – it twists but does not travel any distance. At the equator, the pendulum travels a wide path around the Earth’s axis but does not even begin to make a circle – it travels but it does not twist at all.
A Foucault pendulum placed in between the pole and the equator is affected by both twisting and travelling. The closer it is to the pole, the faster it circles. The library’s pendulum, located at 38 degrees, six minutes, does a complete circle about every 38 hours. Because air resistance would stop the pendulum’s motion, magnets at the top gently pull the pendulum to keep it moving, and the pendulum is suspended in a way that allows it to swing freely, regardless of the building’s movement.
For a more in-depth explanation of how a pendulum demonstrates the rotation of the earth, read About Foucault Pendulums at the California Academy of Sciences."
www.lexpublib.orgMore info on previous history of earth wobble anomalies in past few years (complete with graphs/chart)
www.michaelmandeville.com more to keep an eye on...(magnetosphere)
www2.nict.go.jp
www.en.wikipedia.org Recent work by scientists and geologists Adam Maloof of Princeton University and Galen Halverson of Paul Sabatier University in Toulouse, France, indicates that
Earth indeed rebalanced itself around 800 million years ago during the Precambrian time period.[10] They tested this idea by studying magnetic minerals in sedimentary rocks in a Norwegian archipelago. Using these minerals, Maloof and Halverson found that the north pole shifted more than 50 degrees — about the current distance between Alaska and the equator — in less than 20 million years. This reasoning is supported by a record of changes in sea level and ocean chemistry in the Norwegian sediments that could be explained by true polar wander, the team reports in the September–October 2006 issue of the Geological Society of America Bulletin.[11]
Research using GPS, conducted by Geoffery Blewitt of the University of Nevada, has shown that normal seasonal changes in the distribution of ice and water cause minor movements of the poles.
"Using these minerals, Maloof and Halverson found that the north pole shifted more than 50 degrees — about the current distance between Alaska and the equator — in less than 20 million years. This reasoning is supported by a record of changes in sea level and ocean chemistry in the Norwegian sediments that could be explained by true polar wander, the team reports in the September–October 2006 issue of the Geological Society of America Bulletin.[11]"