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Abstract. The utilization of the spatial resources of refuge type, size and depth placement is investigated in the three sympatric species of Acanthemblemaria at the cape region of Baja California, Mexico. A. balanorum occupies barnacle testes (Balanus tintinnabulum), A. macrospilus occupies barnacles and mollusk tubes (vermetid gastropods and pholadids), and A. crockeri occupies only mollusk tubes (pholadids). Refuge diameter overlap is higher than overlap in depth. A. crockeri consistently occupies depths below 5m. Competition experiments for barnacle refuges among the three species indicate that A. balanorum is a superior competitor for such refuges. Prior residency of a less superior species changes the outcome of refuge competition in its favor. The morphological specialization of A. balanorum and A. macrospilus is evident in a high correlation between head size and standard length. A. balanorum selects refuges with entrance diameters highly correlated to standard length. 相似文献
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Donald J. Walter Douglas N. Lambert David C. Young Kevin P. Stephens 《Geo-Marine Letters》1997,17(4):260-267
Real-time trackline plots of surficial sediment acoustic impedance delineate several sedimentary facies off Garden Key in
the Dry Tortugas. The sea floor within a 6×6 km surveyed area consists of carbonate muds (silts), sands and shell, rock, and
live corals. The 4-kHz acoustic data supports this finding by providing a pictographic representation of the distribution
and structure of several sediment facies types. Plotting the gridded acoustic data with commercial mapping software (Surfer)
provides a three-dimensional (3D) perspective of the bottom topography with a color contour map of surficial sediment impedance
(upper 0.4 m) draped over the 3D surface. 相似文献
77.
A simple shaker table for seismometer calibration 总被引:1,自引:0,他引:1
Frederick K. Duennebier George H. Sutton David Harris David A. Byrne 《Marine Geophysical Researches》1984,6(3):311-328
A unique and simple shaker table (shake table or shaking table), designed, constructed, and installed at the Hawaii Institute of Geophysics, has proven to be a valuable aid in testing and calibrating short period seismometers, as well as ocean bottom and ocean sub-bottom seismometer/tilt meter packages. It consists of a platform suspended in a stairwell by a single elastic cord (10 m extended length) driven by GeoSpace HS-10 geophones. Platform motion is monitored by orthogonal reference geophones and tilt meters. The relatively low natural periods of the platform, about 1.9 sec vertical and 6.5 sec horizontal, provide sufficient isolation from local vibrations that calibration can be made near operational amplitudes. Vertical or horizontal driver geophones can be driven by a commercial signal generator or white noise generator, or from magnetic tape output. The table can also be tilted with respect to the drivers to determine tilt tolerances and to calibrate tilt meters. A Hewlett-Packard 3582-A spectrum analyzer, used to analyze both reference and output signals, provides near real-time system cabibration and is an efficient means for investigating parasitic system resonances. The analyzer can also provide a white noise signal source to the driver geophones.Hawaii Institute of Geophysics Contribution 1443. 相似文献
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Toshiro Saino Alexander Bychkov Chen-Tung Arthur Chen Paul J. Harrison 《Journal of Oceanography》2004,60(1):1-4
This special issue is comprised of 13 papers, including this overview, and focuses on the synthesis of the Joint Global Ocean
Flux Study (JGOFS) in the North Pacific which took place from 1997 through 2003. The effort was led by the JGOFS North Pacific
Synthesis Group, with the aim of quantifying CO2 drawdown by physical and biological pumps in the North Pacific by identifying and studying the regional, seasonal to inter-annual
variations in the key processes, and understanding their regulating mechanisms. Emphasis was placed on the similarities and
differences of the biogeochemical regimes in the eastern and western subarctic Pacific. Effort was also made to address the
future research directions which arose from the scientific findings during the North Pacific JGOFS process study. A brief
overview of the papers from view points of CO2 drawdown by physical and biological pumps, spatial variability, and temporal variability from seasonal to decadal scales
is made, followed by suggestions for the directions of future research.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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