Earth Systems  Polar Motion Monitor
The
Wandering Poles of the Earth
1861-2001
Drift
Statistics For Each Wobble Spiral of 6.5 Years
by Michael Wells Mandeville
|
|
|
|
(overlap) |
|
|
|
|
period |
|
|
cum since first drift |
drift |
|
|
Chart |
Wobble Spiral |
|
spans |
begin |
end |
years |
net
motion |
ave
as/yr |
in
centimeters |
in
inches |
total
yrs |
total
drift |
ave
as/yr |
cents/yr |
inches/yr |
502 |
1861 |
to |
1890 |
30 |
|
|
|
0 |
|
|
|
|
|
|
|
no
drift is apparent |
|
1890 |
to |
1898 |
9 |
|
|
|
0 |
|
|
|
|
|
|
|
no
drift is apparent |
|
1898 |
to |
1903 |
6 |
|
|
|
0 |
|
|
|
|
|
|
|
no
drift is apparent |
502 |
1903 |
to |
1909 |
7 |
|
|
|
0 |
|
|
|
|
|
|
|
no
drift is apparent |
503 |
1909 |
to |
1916 |
8 |
1861 |
1916 |
56 |
0 |
0 |
|
|
56 |
0 |
0 |
|
no
drift is apparent |
504 |
1916 |
to |
1923 |
8 |
|
|
|
|
|
|
|
|
|
|
|
slight
drift apparent but incalcuable |
505 |
1923 |
to |
1931 |
9 |
1916 |
1931 |
15 |
0.07 |
0.0047 |
14.406 |
5.671 |
15 |
0.0047 |
0.000311 |
14.406 |
5.671 |
506 |
1931 |
to |
1939 |
9 |
|
|
|
|
|
|
|
|
|
|
|
|
507 |
1939 |
to |
1945 |
7 |
1931 |
1945 |
14 |
0.075 |
0.0054 |
16.538 |
6.510 |
29 |
0.1450 |
0.005 |
15.435 |
6.076 |
|
1945 |
to |
1952 |
8 |
|
|
|
|
|
|
|
|
|
|
|
|
508 |
1952 |
to |
1958 |
7 |
1945 |
1958 |
13 |
0.04 |
0.0031 |
9.498 |
3.739 |
42 |
0.1850 |
0.004405 |
13.598 |
5.353 |
509 |
1958 |
to |
1964 |
7 |
1958 |
1964 |
6 |
0.085 |
0.0142 |
43.733 |
17.216 |
48 |
0.2700 |
0.005625 |
17.364 |
6.836 |
510 |
1964 |
to |
1971 |
8 |
1964 |
1971 |
7 |
0.025 |
0.0036 |
11.025 |
4.340 |
55 |
0.2950 |
0.005364 |
16.558 |
6.518 |
| 511 |
1971 |
to |
1977 |
7 |
1971 |
1977 |
6 |
0.045 |
0.0075 |
23.153 |
9.114 |
61 |
0.3400 |
0.005574 |
17.206 |
6.773 |
| 511 |
1977 |
to |
1983 |
7 |
1977 |
1983 |
6 |
0.02 |
0.0033 |
10.290 |
4.051 |
67 |
0.3600 |
0.005373 |
16.587 |
6.530 |
| 512 |
1983 |
to |
1990 |
8 |
1983 |
1990 |
|
|
|
|
|
|
|
|
|
|
| 512 |
1990 |
to |
1996 |
7 |
1990 |
1996 |
13 |
0.025 |
0.0019 |
5.937 |
2.337 |
80 |
0.3850 |
0.004813 |
14.856 |
5.848 |
speculaton |
1996 |
to |
2001 |
6 |
1996 |
2001 |
5 |
0.02 |
0.0040 |
12.348 |
4.861 |
85 |
0.3350 |
0.003941 |
12.166 |
4.789 |
this last line 96 to 2001 is highly speculative and should not used in any
averaging.
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