[time-nuts] UTC and leap seconds
Magnus Danielson
magnus at rubidium.dyndns.org
Sat Jun 12 11:45:11 UTC 2010
On 06/12/2010 02:33 AM, Hal Murray wrote:
>
> jimlux at earthlink.net said:
>> The Chilean earthquake changed the angular rotation rate (or, probably more
>> accurately, changed the direction of the axis of rotation as well)
>> of the earth a small amount, as do most large earthquakes.
>
> Has anybody measured that?
>
> Is there a good URL on this? (predictions if not data) All I've found so
> far is a small NASA press release predicting 1.26 microseconds per day:
> http://www.nasa.gov/topics/earth/features/earth-20100301.html
> (and a zillion news sources repeating it)
>
> 1 microsecond/day is 1 part in 1E11.
There is one place that keeps track of these things, the IERS. Their
Bullentin B provides monthly reports of earth rotation observatoins.
The bulletin for relevant period of time is:
ftp://hpiers.obspm.fr/iers/bul/bulb_new/bulletinb.266
ftp://hpiers.obspm.fr/iers/bul/bulb_new/bulletinb.267
Explanations is in:
ftp://hpiers.obspm.fr/iers/bul/bulb_new/bulletinb.pdf
Clause 3 is of most interest, look at the OMEGA column (appended the
bulletin b 267 data for a more complete time-series around the date of
interest).
3 - EARTH ANGULAR VELOCITY : DAILY FINAL VALUES OF LOD, OMEGA AT 0hUTC
LOD : Excess of the Length of day - 86400 s TAI
OMEGA : Earth angular velocity
Description: ftp://hpiers.obspm.fr/iers/bul/bulb_new/bulletinb.pdf
DATE MJD LOD sigma OMEGA sigma
(0 h UTC) ms ms mas/ms mas/ms
2010 2 2 55229 1.8681 0.0026 15.04106685346 0.00000000045
2010 2 3 55230 1.7864 0.0026 15.04106686768 0.00000000045
2010 2 4 55231 1.5385 0.0025 15.04106691084 0.00000000044
2010 2 5 55232 1.2685 0.0025 15.04106695784 0.00000000044
2010 2 6 55233 1.0554 0.0025 15.04106699494 0.00000000044
2010 2 7 55234 0.8434 0.0025 15.04106703185 0.00000000044
2010 2 8 55235 0.6803 0.0024 15.04106706024 0.00000000042
2010 2 9 55236 0.5753 0.0023 15.04106707852 0.00000000040
2010 2 10 55237 0.5670 0.0024 15.04106707996 0.00000000042
2010 2 11 55238 0.6693 0.0025 15.04106706215 0.00000000044
2010 2 12 55239 0.8218 0.0025 15.04106703561 0.00000000044
2010 2 13 55240 0.9954 0.0025 15.04106700538 0.00000000044
2010 2 14 55241 1.1595 0.0023 15.04106697682 0.00000000040
2010 2 15 55242 1.3130 0.0022 15.04106695009 0.00000000038
2010 2 16 55243 1.4267 0.0022 15.04106693030 0.00000000038
2010 2 17 55244 1.4902 0.0022 15.04106691925 0.00000000038
2010 2 18 55245 1.4938 0.0022 15.04106691862 0.00000000038
2010 2 19 55246 1.4125 0.0022 15.04106693277 0.00000000038
2010 2 20 55247 1.2918 0.0022 15.04106695379 0.00000000038
2010 2 21 55248 1.1747 0.0023 15.04106697417 0.00000000040
2010 2 22 55249 1.0692 0.0024 15.04106699254 0.00000000042
2010 2 23 55250 0.9790 0.0023 15.04106700824 0.00000000040
2010 2 24 55251 0.9995 0.0023 15.04106700467 0.00000000040
2010 2 25 55252 1.1888 0.0023 15.04106697172 0.00000000040
2010 2 26 55253 1.4628 0.0023 15.04106692402 0.00000000040
2010 2 27 55254 1.7307 0.0023 15.04106687738 0.00000000040
2010 2 28 55255 1.9743 0.0024 15.04106683497 0.00000000042
2010 3 1 55256 2.0942 0.0024 15.04106681410 0.00000000042
2010 3 2 55257 2.0008 0.0023 15.04106683036 0.00000000040
2010 3 3 55258 1.7548 0.0022 15.04106687318 0.00000000038
2010 3 4 55259 1.4776 0.0023 15.04106692144 0.00000000040
2010 3 5 55260 1.2055 0.0022 15.04106696881 0.00000000038
2010 3 6 55261 0.9666 0.0022 15.04106701040 0.00000000038
2010 3 7 55262 0.8211 0.0022 15.04106703573 0.00000000038
2010 3 8 55263 0.7631 0.0022 15.04106704582 0.00000000038
2010 3 9 55264 0.8364 0.0022 15.04106703306 0.00000000038
2010 3 10 55265 0.9253 0.0022 15.04106701759 0.00000000038
2010 3 11 55266 0.9827 0.0023 15.04106700760 0.00000000040
2010 3 12 55267 1.0913 0.0022 15.04106698869 0.00000000038
2010 3 13 55268 1.1363 0.0022 15.04106698086 0.00000000038
2010 3 14 55269 1.1201 0.0021 15.04106698368 0.00000000037
2010 3 15 55270 1.1643 0.0020 15.04106697598 0.00000000035
2010 3 16 55271 1.2107 0.0021 15.04106696790 0.00000000037
2010 3 17 55272 1.2396 0.0021 15.04106696287 0.00000000037
2010 3 18 55273 1.1762 0.0020 15.04106697391 0.00000000035
2010 3 19 55274 0.9807 0.0020 15.04106700794 0.00000000035
2010 3 20 55275 0.8169 0.0020 15.04106703646 0.00000000035
2010 3 21 55276 0.6733 0.0019 15.04106706146 0.00000000033
2010 3 22 55277 0.5584 0.0019 15.04106708146 0.00000000033
2010 3 23 55278 0.5350 0.0019 15.04106708553 0.00000000033
2010 3 24 55279 0.6588 0.0018 15.04106706398 0.00000000031
2010 3 25 55280 0.9540 0.0018 15.04106701259 0.00000000031
2010 3 26 55281 1.3046 0.0019 15.04106695156 0.00000000033
2010 3 27 55282 1.6142 0.0019 15.04106689766 0.00000000033
2010 3 28 55283 1.8512 0.0018 15.04106685640 0.00000000031
2010 3 29 55284 1.9790 0.0018 15.04106683415 0.00000000031
2010 3 30 55285 1.9111 0.0019 15.04106684597 0.00000000033
2010 3 31 55286 1.6414 0.0019 15.04106689292 0.00000000033
2010 4 1 55287 1.3068 0.0018 15.04106695117 0.00000000031
Yes, we see a dip there... but looking at the two-month data we se a
regular pattern creating a dip there... and the lack of jump is interesting.
Essentially... I can't see it here.
Cheers,
Magnus
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