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Chapman, CH, Orcutt JA, Cary PW.  1987.  Least squares fitting of marine seismic refraction data. ( Vogel A, Ed.)., Braunschweig, Federal Republic of Germany (DEU): Friedrich Vieweg & Sohn, Braunschweig AbstractWebsite
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Shipboard Sci Party, L203.  2003.  Leg 203 Preliminary Report: Dynamics of Earth and Ocean Systems. Preliminary Report Ocean Drilling Program. Abstract
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Riedesel, MA, Moore RD, Orcutt JA.  1990.  Limits of Sensitivity of Inertial Seismometers with Velocity Transducers and Electronic Amplifiers. Bulletin of the Seismological Society of America. 80:1725-1752. AbstractWebsite

Portable instruments such as ocean bottom seismographs and the PASSCAL recorders often use rugged, portable geophones. The desire to use such sensors for relatively low-frequency work has raised questions about the limits of their sensitivity. The lower and upper frequency limits of performance of seismic sensors are determined by the sensor's mass, period, and Q, and by the amplifiers used with those sensors. We have tested Mark Products 1 Hz, 2 Hz, and 4.5 Hz velocity transducers against Streckeisen seismometers in order to examine the limits of their performance in measuring ground noise, particularly at low frequencies. Among the velocity transducers, only the 1 Hz Mark Products L-4 sensor provided good resolution of the 6-sec microseism peak. For this sensor, the lower limits of sensitivity was at approximately 0.06 Hz, although this depends on the amplifier used and the noise level at a given site. The amplifiers examined included conventional, low power, and commutating auto-zero operational amplifiers. It was found that the noise levels of the amplifiers intersected the ground noise level at frequencies ranging between 0.06 and 0.2 sec, depending on the amplifier and the exact circuit design. Measurements indicated that by modeling the amplifier noise for a given circuit correctly, the performance of an amplifier can be predicted with a high degree of accuracy, obviating the need for actual circuit construction to determine performance in the field. Given the very steep slope of the ground noise spectrum between 0.05 and 0.1 Hz and the rapid fall off in a seismometer's output below its resonant frequency, it would require a lowering of amplifier noise by more than an order of magnitude to be able to resolve ground noise a frequencies lower than 0.05 Hz using relatively small geophones such as the L-4. To resolve ground noise at lower frequencies, it is necessary to use a seismometer with a displacement transducer to sense the mass position, such as Guralp or Streckeisen sensors.

Orcutt, J, de Groot-Hedlin C, Hodgkiss W, Kuperman W, Munk W, Vernon F, Worcester P, Bernard E, Dziak R, Fox C, Chiu CS, Collins C, Mercer J, Odom R, Park M, Soukup D, Spindel R.  2000.  Long-Term Observations in Acoustics—The Ocean Acoustic Observatory Federation. Oceanography. 13:57-63.   10.5670/oceanog.2000.35   Abstract

The Ocean Acoustic Observatory Federation (OAOF) includes several laboratories and universities: the Institute of Geophysics and Planetary Physics (IGPP) and the Marine Physical Laboratory (MPL) at the Scripps Institution of Oceanography, the Pacific Meteorological and Environmental Laboratory (PMEL) of NOAA, the Naval Postgraduate School (NPS), and the Applied Physics Laboratory at the University of Washington (UW/APL). The OAOF integrates the previously independent activities of its member institutions in the collection of long time series from acoustic arrays in the Pacific. The funded activities include the outfitting and operation of retired Sound Surveillance System (SOSUS) stations, research in earthquake and volcano seismicity, the monitoring of marine mammal behavior, the use of acoustic methods for ocean acoustic tomography and thermometry, and the development of a fundamental understanding of the coupling of elastic waves from volcanoes and earthquakes into the ocean sound channel.

Adair, RG, Orcutt JA, Jordan TH.  1986.  Low-Frequency Noise Observations in the Deep Ocean. Journal of the Acoustical Society of America. 80:633-645.   10.1121/1.394477   AbstractWebsite

Simultaneous measurements of ocean‐bottom infrasonic and ocean‐bottom and sub‐bottom seismic noise in the frequency band 0.1–20 Hz are presented. The data were obtained in 5.5‐km‐deep water in the South Central Pacific with a triaxial borehole seismograph and six triaxial ocean‐bottom seismographs having externally mounted hydrophones. The borehole sensors were emplaced 54 m within basement rock overlain by 70 m of pelagic clay. In the band 0.1–1 Hz, noise propagation as seismic modes trapped in the seafloor is supported by observed spectral coherences, cross phases, and ratios between ocean‐bottom pressure and vertical ground motion, and by the relatively lower noise levels in the borehole. Noise variations in this band are clearly correlated with changes in local wind direction and speed, presumably through ocean‐bottom pressure fluctuations caused by nonlinear wind wave–wind wave and wind wave–swell interaction.