Navigation Question

  • #1
316
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Since the Tsunami, changed the speed of our orbit, and set us off a bit on the planetary tilt; will every compass, and navigational instrument, in every vehicle, sub, satellite, plane, etc, have to be recalibrated? I think that a few millimeters, could become great, over thousands of miles. Or a few millimeters could be catastrophic, if there is a zero tolerance for error. What have you heard about this?
 

Answers and Replies

  • #2
Cliff_J
Science Advisor
789
7
According to the TV shows I've seen on Discovery the rotation of the earth was slowed by 3 microseconds, the same amount occurs every 100 days because of the effect the moon has on the earth. The north pole shifted something like an inch or two and that would be the largest manifestation of the inclination shift.

For consumer gear, this is well below the margin of error. For the military, I doubt they would tell anyone if it wasn't. :smile:

Cliff
 
  • #3
BobG
Science Advisor
Homework Helper
185
81
Dayle Record said:
Since the Tsunami, changed the speed of our orbit, and set us off a bit on the planetary tilt; will every compass, and navigational instrument, in every vehicle, sub, satellite, plane, etc, have to be recalibrated? I think that a few millimeters, could become great, over thousands of miles. Or a few millimeters could be catastrophic, if there is a zero tolerance for error. What have you heard about this?
You're slightly inaccurate. The Tsunami changed the speed of the Earth's rotation, not the speed of our orbit.

The Earth's rotation rate and the orientation of its axis changes constantly. Even tiny errors can build up over time, which is why both are analyzed and recorded by the International Earth Rotation Service (the US Naval Observatory cooperates with the IERS as kind of the US component of this organization).
 
  • #4
russ_watters
Mentor
20,126
6,644
Dayle Record said:
Since the Tsunami, changed the speed of our orbit, and set us off a bit on the planetary tilt; will every compass, and navigational instrument, in every vehicle, sub, satellite, plane, etc, have to be recalibrated? I think that a few millimeters, could become great, over thousands of miles. Or a few millimeters could be catastrophic, if there is a zero tolerance for error. What have you heard about this?
Actually, a few milimeters, over thousands of miles, becomes negligible. The crust shift at the fault line may have been 60 feet (not sure if that was permanent), but hundreds of miles away, its much smaller. Thousands of miles away, its microscopic.
 
  • #5
62
0
The location of the poles vary throughout the year... by a few inches.

And the rotation rate changes by a few tens of milliseconds throughout the year.

So, no biggie... this tsunami is not a significantly huge terrestrial event (despite what the media is saying... and the chicken-littles are believing).

See here for more info on pole location movement.

Cheers...
 
  • #6
316
2
Thanks for any and all answers, and corrections.
 
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