What is the value of g in Claremont?

The value of g on the Earth's surface varies from point to point because of several effects:

• the Earth is not spherical (it is more closely an oblate spheroid)
• The Earth is rotating
• the distribution of mass density in the Earth is not homogeneous
• the Moon and Sun exert tidal accelerations
• etc., etc...

The nominal value of g on a smooth Earth, taking into account oblateness and rotation is, at sea level:

        (1)

where f is the latitude of the location. The latitude of HMC in Claremont is 34.1066°. Also, Claremont is approximately 300 m above the ellipsoid reference level, which reduces g by about 2 ¥ 10^-6 m/s² per meter of elevation, or about 6 ¥ 10^-4 m/s². Because of other variations and factors not accounted for here, this set of corrections is probably uncertain at the level of approximately ±1 ¥ 10^-4 m/s², or ±0.001%.

So, putting this all together, to the uncertainty that we can report using this information, the acceleration of gravity on the HMC campus is

Updated 8/8/99 by Peter N. Saeta .