Grain size analysis of ODP Site 162-984

Past changes in the freshwater balance of the surface North Atlantic Ocean are thought to have influenced the rate of deep-water formation, and consequently climate (Broecker and Denton, 1989, doi:10.1016/0016-7037(89)90123-3; Manabe and Stouffer, 1996; doi:10.1038/378165a0). Although water-mass proxies are generally consistent with an impact of freshwater input on meridional overturning circulation (Boyle and Keigwin, 1987, doi:10.1038/330035a0), there has been little dynamic evidence to support this linkage. Here we present a 25,000 year record of variations in sediment grain size from south of Iceland, which indicates vigorous bottom-water currents during both the last glacial maximum and the Holocene period. Together with reconstructions of North Atlantic water-mass distribution, vigorous bottom currents suggest a shorter residence time of northern-source waters during the last glacial maximum, relative to the Holocene period. The most significant reductions in flow strength occur during periods that have been associated with freshening of the surface North Atlantic. The short-term deglacial oscillations in bottom current strength are closely coupled to changes in Greenland air temperature, with a minimum during the Younger Dryas cold reversal and a maximum at the time of rapid warming at the onset of the Holocene. Our results support a strong connection between ocean circulation and rapid climate change.

(Appendix) Grain-size distribution, calcium carbonate content and proportion of cemented aggregates in ODP Site 133-820

The textural and compositional characteristics of the 400 m sequence of Pleistocene wackestones and packstones intersected at Ocean Drilling Program (ODP) Site 820 reflect deposition controlled by fluctuations in sea-level, and by variations in the rate of sediment supply. The development of an effective reefal barrier adjacent to Site 820, between 760 k.y. and 1.01 Ma, resulted in a marked reduction in sediment accumulation rates on the central Great Barrier Reef outermost shelf and upper slope. This marked change corresponds with the transition from sigmoidal prograding seismic geometry in the lower 254 m of the sequence, to aggradational geometry in the top 146 m. The reduction in the rate of sediment accumulation that followed development of the reefal barrier also caused a fundamental change in the way in which fluctuations in sea-level controlled sediment deposition. In the lower, progradational portion of the sequence, sea-level cyclicity is represented by superimposed coarsening-upward cycles. Although moderately calcareous throughout (mostly 35%-75% CaCO3), the depositional system acted in a similar manner to siliciclastic shelf depositional systems. Relative sea-level rises resulted in deposition of more condensed, less calcareous, fine, muddy wackestones at the base of each cycle. Sea-level highstands resulted in increased sedimentation rates and greater influx of coarse bioclastic material. Continued high rates of sedimentation of both coarse bioclastic material and mixed carbonate and terrigenous mud marked falling and low sea-levels. This lower part of the sequence therefore is dominated by coarse packstones, with only thin wackestone intervals representing transgressions. In contrast, sea-level fluctuations following formation of an effective reefal barrier produced a markedly different sedimentary record. The more slowly deposited aggradational sequence is characterized by discrete thin interbeds of relatively coarse packstone within a predominantly fine wackestone sequence. These thin packstone beds resulted from relatively low sedimentation rates during falling and low sea-levels, with much higher rates of muddy sediment accumulation during rising and high sea-levels. The transition from progradational to aggradational sequence geometry therefore corresponds to a transition from a "siliciclastic-type" to a "carbonate-type" depositional system.

Biological treatment of wood preserving site groundwater by BioTrol, Inc. : applications analysis report.

Mode of access: Internet.

Analytical modeling of driver response in crash avoidance maneuvering. Volume IV: user's guide for linear analysis, nonlinear simulation, part task simulation. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Sensitivity analysis of vehicle design attributes that affect vehicle response in critical accident situations - part 1: user's manual. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Analysis of head response to torso acceleration. Volume I - development of performance requirements. Final report.

Transportation Systems Center, Cambridge, Mass.

Analysis of head response to torso acceleration. Volume II - description of data retrieval, analysis and display software. Final report.

Transportation Systems Center, Cambridge, Mass.

Sensitivity analysis of vehicle design attributes that affect vehicle response in critical accident situations - part II: technical report. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

NONSAP : a structural analysis program for static and dynamic response of nonlinear systems /

Photocopy of original: Berkeley : Structural Engineering Laboratory, University of California, 1974.

CERCLIS (Comprehensive environmental response, compensation, and liability information system) site location extract data element dictionary.

PB90-215120

Phase II final report, computerized site security monitor and response system /

Issued Mar. 1979.

Foreign direct investment in the United States : an update : review and analysis of current developments : a report submitted to the Committee on Energy and Commerce, the Committee on Ways and Means, and the Committee on Foreign Affairs of the House of Representatives, to the Committee on Finance, the Committee on Commerce, Science and Transportation, and the Committee on Foreign Relations of the Senate, and to the Joint Economic Committee of the Congress in response to section 3(a) of the Foreign Direct Investment and International Financial Data Improvements Act of 1990.

"January 1995."

Mount telemark site analysis.

Cover title.

Effects of filter response on analysis of aircraft noise data /

Mode of access: Internet.