Analysis of IDA gravimeter data between 1983 and 1994 and GEOSCOPE data between 1988 and 1994 show that fundamental modes of the Earth, for frequencies between 2 and 7 mHz, are excited even on seismically quiet days. Amplitudes of acceleration are slightly less than one ngal(10-9gal). Examination of a sequence of shorter time interval records suggests that the Earth is oscillating continuously. Currently, both atmospheric excitation and tectonic motions are possible cause(s) of these oscillations. ¿ 1998 American Geophysical Union