Belmont Report - Long-Term Dynamics

SLR Measures the Long-Term Dynamics of the Solid Earth, Oceans, and Ice Fields

Angular Momentum Exchange

SLR determinations of the Earth's rotation and orientation reveal changes in the distribution of mass and exchange of angular momentum in the atmosphere-hydrosphere-cryosphere-solid Earth system. Variations in the orientation of the Earth's polar rotation axis over 14 years are shown.

Orientation of the Earth's polar rotation axis

Geocenter and Station Height Variations

SLR determination of the changes in the geocentric height of stations coupled with determination of the motion of the station network with respect to the geocenter at the few mm level provides an unambiguous reference for studies of sea level variations and post-glacial rebound. Shown are time histories of the apparent changes in the position of the Earth's geocenter (X and Y) with respect to the SLR network; monitoring at the millimeter level is now being achieved (Watkins and Eanes, 1993).

Time histories of the apparent changes in the position of the Earth's geocenter

Time histories of the apparent changes in the position of the Earth's geocenter

SLR provides a precise determination of the Earth's crustal response to ocean and atmospheric loading. The height of a station changes due to the surface/crustal loading caused by ocean tides and atmospheric pressure changes. The predicted height and variations of an island site are shown.

Predicted height and variations

Watkins and Eanes, Adv. Space. Res., 13 (11), 251-255, 1993.