Gravity of Earth Gravity acceleration is a vector quantity. In a spherically symmetric Earth, gravity would point directly towards the sphere's centre. As the Earth is slightly flatter, there are consequently slight deviations in the direction of gravity. Tools exist for calculating the strength of gravity at various cities around the world. The effect of latitude can be clearly seen with gravity in high-latitude cities: Anchorage (9.826 m/s), Helsinki (9.825 m/s), being about 0.5% greater than that in cities near the equator: Kuala Lumpur (9.776 m/s), Manila (9.780 m/s). The effect of altitude can be seen in Mexico City (9.776 m/s; altitude ),
Gaithersburg Latitude Observatory one of the four original observatories built by 1899 — tracking the degree of "wobble" occurring on the earth's north-south axis and resultant variation of latitude. The Observatory — along with observatories in Cincinnati, Ohio; Ukiah, California; Mizusawa, Japan; Charjui in Russian Turkestan; and Carloforte, Sardina, Italy — performed in concert to carry out a coordinated program of star observation designed to investigate and calculate the degree of earth "wobble" or latitude variation. On the grounds of the Gaithersburg Latitude Observatory stands a plaque that reads: This small framed structure played a key role in the scientific investigation of the