Figure 15. Vertical component spectra from the seafloor, buried, and borehole installations at OSN-1 are compared with the spectra from the buried installation at H2O and the KIP GSN station on Oahu. H2O has extremely low noise levels above 5 Hz and near the microseism peak from 0.1 to 0.3 Hz. H2O has high noise levels below 50 mHz. Otherwise H2O levels are comparable to the OSN borehole and KIP levels. The sediment resonances at H2O near 1 and 3 Hz are very prominent.