Plate tectonic theory suggests that present-day topography can be explained by the
repeated interactions between the tectonic plates moving along Earth's surface. However …

Fig. 4.• hematic Power S• cua of Variations in• e• ng• of t• Day. observed solid Earth
nutations, and to determine the non-hydrostatic part of the Core-Mantle Boundary (CMB) …

Maps of the fluid flow at the core surface are important for a number of reasons: foremost
they may provide some insight into the workings of the geodynamo and may place useful …

Recent improvements in geodetic data and practical meteorology have advanced research
on fluctuations in the Earth's rotation. The interpretation of these fluctuations is inextricably …

The evolution of the obliquity of the ecliptic (ε), the Earth's axial tilt of 23.5°, may have greatly
influenced the Earth's dynamical, climatic and biotic development. For ε> 54°, climatic …

Observation of the variations in the Earth's rotation at time scales ranging from subdiurnal to
multidecadal allows us to learn about its deep interior structure. We review all three types of …

The 75 year history of the American Geophysical Union has accompanied great advances in
our understanding of the physics and chemistry of the transition zone between the Earth's …

We present the results of calculations to determine fluid velocities at the core-mantle
boundary from magnetic data collected over the period 1840-1990. The calculations adopt …

This paper reviews current knowledge about the Earth's core and the overlying deep mantle
in terms of structure, chemical and mineralogical compositions, physical properties, and …

Measured changes in the Earth's length of day on a decadal timescale are usually attributed
to the exchange of angular momentum between the solid mantle and fluid core. One of …