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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Ocean-bottom seismometer | 2/2 | https://en.wikipedia.org/wiki/Ocean-bottom_seismometer | reference | science, encyclopedia | 2026-05-05T09:43:54.235687+00:00 | kb-cron |
== Disadvantages == The environment of these deployments complicates standard methods that are used in analyzing the data because of the ocean on top of the seismometer, as opposed to free-air above a typical land station. These seismometers also have a decreased signal-to-noise ratio because of noise created by the movement of the oceans due to wind driven tides, particularly at periods of 7 and 14 seconds. This long period motion and current flowing around the seismometer can create problems of long period noise on the horizontal components because the soft (saturated) sediment that the seismometer is resting on is more susceptible to allow the seismometer to tilt and ideally, the horizontal component will not move and be perpendicular to gravity to get the best results out of the seismometer. The saturated sediment also reduces signal-to-noise ratio significantly because the velocity of the P and S waves decreases and the seismic waves get trapped in the sediment layer creating a large amplitude ringing due to the conservation of energy.
== Notable deployments == One of the largest OBS deployments ever was The Big Mantle Electromagnetic and Tomography (Big MELT) Experiment, involving almost 100 OBS in the East Pacific Rise with the goal of understanding magma generation and mid-ocean ridge development. The Cascadia Initiative is an offshore/onshore deployment to observe the deformation of the Juan de Fuca and Gorda plates, as well as topics ranging from megathrust earthquakes to volcanic arc structure in the Pacific Northwest. The Hawaiian PLUME (Plume-Lithosphere Undersea Melt Experiment) was an onshore/offshore (predominantly offshore) deployment to better understand what type of mantle plume is beneath Hawaii and to better understand the mantle upwelling in this region and its relationship to the lithosphere. The Asthenospheric and Lithospheric Broadband Architecture from the California Offshore Region Experiment (ALBACORE) deployment from 2010 to 2011 of 34 OBS to help better understand the tectonic interaction at the Pacific-North America plate boundary and deformation styles of the Pacific plate and the nearby microplates.
== References ==
== External links == "French OBS" Archived 2014-01-16 at the Wayback Machine "https://woodshole.er.usgs.gov/operations/obs/whatobs.html" "K.U.M. OBS" "GEOMAR Technologie"