anart
A Disturbance in the Force
From: http://www.michaelmandeville.com/earthmonitor/polarmotion/2006_wobble_anomaly.htm
The Anomaly In The Earth’s Wobble Continues
The Polar Motion Anomaly of 2005/2006
ECB – March 1, 2006, MWM) After nearly 120 days of deeply anomalous motion which began at the beginning of November 2005, the Spin Axis is showing some signs of returning to a normal wobble track, but only very slowly. During January the Earth ceased its wobble motion for a full month and then during February the Earth’s motion began to slowly move its wobble track back to the starting point of the current anomaly.
For the past two weeks this motion has been nearly straight up the X Plot (Greenwich Meridian), dipping Greenland/England slightly to the North. But there is still almost no net motion on the Y axis aside from minor quivers such as are typically caused by atmospheric and tidal conditions.
This gradual return to what the track was during 2005 will not normalize the Earth’s Wobble. The old, normal wobble cycle has “lost” at least 120 days, that’s four months out of a 14 month cycle. Thus it is likely that a major phase shift has occurred in both the 14 month wobble cycle and the primary 7 year cycle in the “Chandler Amplitude”, known here as the Primary Axis Cycle.
This “event” may be even more radical that a truncation of the cycle. It appears as of March 1, 2006 that an entirely new cycle is generating itself around a radically shifted average or mean location for the Spin Axis. This new cycle appears to be shifted about 180 degrees in phase from the old cycle. This appearance, however, may deepen or gradually disappear during the next three months. More likely than not we will have to wait until Summer 2006 to “cap” our description of just what this anomaly is.
For the latest Wobble Tracker graph of Polar Motion as of February 21, 2006, see
http://www.michaelmandeville.com/earthmonitor/polarmotion/plots/ wobbletrac_Feb21_06.gif
(Anart here - this link is not currently working, I'll try to find another to the graphic)
In the Wobble Tracker graph the small red “tip” is where the wobble “paused” during January. The small blue line headed south coming down from it is the motion of the wobble ~February 10-22. The spiral black line is the track of the wobble during 2005 (until January 5, 2006)
Normally at this time in the spiral motion of the wobble, the track of the moving Spin Axis would be moving to the right hand of the graphs of polar motion. The track should be nearly at the lowest point it would reach this year (on the Wobble Tracker chart) and should begin to slowly spiral back up towards the top of the graph no later than about the beginning of May at the latest.
AS PREVIOUSLY OBSERVED: This anomaly is still on-going though the wobble is obviously beginning to recover part of its old pattern. Quite obviously we can deduce that there is a relatively large, developing anomaly in the spiraling motion of the spin axis, including a major phase shift, a shortening of the length of the normal 7 year cycle, the tightening of the spiral motion into an exceptionally small spiral, and a major acceleration in the drift of the Spin Axis (secular drift of the poles, or so-called True Polar Wander).
The Anomaly In The Earth’s Wobble Continues
The Polar Motion Anomaly of 2005/2006
ECB – March 1, 2006, MWM) After nearly 120 days of deeply anomalous motion which began at the beginning of November 2005, the Spin Axis is showing some signs of returning to a normal wobble track, but only very slowly. During January the Earth ceased its wobble motion for a full month and then during February the Earth’s motion began to slowly move its wobble track back to the starting point of the current anomaly.
For the past two weeks this motion has been nearly straight up the X Plot (Greenwich Meridian), dipping Greenland/England slightly to the North. But there is still almost no net motion on the Y axis aside from minor quivers such as are typically caused by atmospheric and tidal conditions.
This gradual return to what the track was during 2005 will not normalize the Earth’s Wobble. The old, normal wobble cycle has “lost” at least 120 days, that’s four months out of a 14 month cycle. Thus it is likely that a major phase shift has occurred in both the 14 month wobble cycle and the primary 7 year cycle in the “Chandler Amplitude”, known here as the Primary Axis Cycle.
This “event” may be even more radical that a truncation of the cycle. It appears as of March 1, 2006 that an entirely new cycle is generating itself around a radically shifted average or mean location for the Spin Axis. This new cycle appears to be shifted about 180 degrees in phase from the old cycle. This appearance, however, may deepen or gradually disappear during the next three months. More likely than not we will have to wait until Summer 2006 to “cap” our description of just what this anomaly is.
For the latest Wobble Tracker graph of Polar Motion as of February 21, 2006, see
http://www.michaelmandeville.com/earthmonitor/polarmotion/plots/ wobbletrac_Feb21_06.gif
(Anart here - this link is not currently working, I'll try to find another to the graphic)
In the Wobble Tracker graph the small red “tip” is where the wobble “paused” during January. The small blue line headed south coming down from it is the motion of the wobble ~February 10-22. The spiral black line is the track of the wobble during 2005 (until January 5, 2006)
Normally at this time in the spiral motion of the wobble, the track of the moving Spin Axis would be moving to the right hand of the graphs of polar motion. The track should be nearly at the lowest point it would reach this year (on the Wobble Tracker chart) and should begin to slowly spiral back up towards the top of the graph no later than about the beginning of May at the latest.
AS PREVIOUSLY OBSERVED: This anomaly is still on-going though the wobble is obviously beginning to recover part of its old pattern. Quite obviously we can deduce that there is a relatively large, developing anomaly in the spiraling motion of the spin axis, including a major phase shift, a shortening of the length of the normal 7 year cycle, the tightening of the spiral motion into an exceptionally small spiral, and a major acceleration in the drift of the Spin Axis (secular drift of the poles, or so-called True Polar Wander).