The Eötvös correction is required for motions along which traverse direction, to account for centrifugal effects?

The Eötvös correction is required for motions along which traverse direction, to account for centrifugal effects?

• A. East-West traverse
• B. North-South traverse
• C. Vertical motion
• D. Diagonal traverse

Answer: (A)

The Eötvös correction accounts for the extra centrifugal acceleration you experience when you carry a gravimeter while moving on the rotating Earth. This centrifugal effect changes as you change your velocity relative to Earth’s rotation, and it shows up most noticeably when you move along parallels, i.e., in the east–west direction. Moving east or west changes your speed around the rotation axis (the North–South axis), altering the centrifugal component and thus the apparent gravity you measure. Moving north–south doesn’t change your distance to the rotation axis in the same way, so the centrifugal change is negligible for first-order corrections. Therefore, the correction is applied for motions along the east–west direction.

The Eötvös correction accounts for the extra centrifugal acceleration you experience when you carry a gravimeter while moving on the rotating Earth. This centrifugal effect changes as you change your velocity relative to Earth’s rotation, and it shows up most noticeably when you move along parallels, i.e., in the east–west direction. Moving east or west changes your speed around the rotation axis (the North–South axis), altering the centrifugal component and thus the apparent gravity you measure. Moving north–south doesn’t change your distance to the rotation axis in the same way, so the centrifugal change is negligible for first-order corrections. Therefore, the correction is applied for motions along the east–west direction.