  Hidden matter that interacts only gravitationally would oscillate at
characteristic frequencies when trapped inside of Earth. For small oscillations
near the center of the Earth, these frequencies are around 300 $\mu$Hz.
Additionally, signatures at higher harmonics would appear because of the
non-uniformity of Earth's density. In this work, we use data from a global
network of gravimeters of the International Geodynamics and Earth Tide Service
(IGETS) to look for these hypothetical trapped objects. We find no evidence for
such objects with masses on the order of 10$^{14}$ kg or greater with an
oscillation amplitude of 0.1 $r_e$. It may be possible to improve the
sensitivity of the search by several orders of magnitude via better
understanding of the terrestrial noise sources and more advanced data analysis.
