Earth and Planetary Science Letters, 53 (1981) 409-418 409 Elsevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands [61 A sediment trap intercomparison study in the Santa Barbara Basin Jack Dymond, Kathy Fischer, Milo Clauson, Richard Cobler Oregon State University, Corvallis, OR ¢7331 (U.S.A.) Wilford Gardner, Mary Jo Richardson Lamon t-Doherty Geological Observatory of Columbia University, Palisades, N Y 10964 (U.S.A.) Wolfgang Berger, Andrew Soutar and Robert Dunbar Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093 (U.S.A.) Received April 21, 1980 Revised version received February 2, 1981 Four sediment traps of radically different design were deployed in the Santa Barbara Basin for approximately 45 days. The measured fluxes ranged from 370 to 774 g m-2 yr I for the different designs. These values lie within flux measurements previously determined for the basin. Compared to the 25-year record (920 g m -2 yr-i), however, all fluxes determined in this experiment are somewhat low. Because this experiment was conducted during a general period of high storm activity and runoff, measurement of greater than average flux was expected. It is probable that the higher flux recorded by the sediments results from a significant input of detritus into the basin by near bottom transport. The chemical composition of trapped material was nearly identical in all four trap designs. The deep cone design, however, had a significantly lower Mn content. Since this trap was the only one in which reducing conditions were produced in the sample container, reduction and mobilization of manganese after collection is believed to have occurred. In spite of the very different designs tested, the factor of two agreement in flux determination and the compositional similarity of the material collected is encouraging for future attempts to directly measure the flux of particulates in the ocean. 1. Introduction In recent years the deployment of sediment traps has become technically feasible in the open ocean. Traps have been used to collect material which is falling through the water column as a means of measuring the flux of solid phases and associated elements [1-6]. Recent laboratory studies suggest the trapping efficiency of different trap designs can vary greatly [7,8]. In order to directly compare the variations in both mass and composition of material collected by traps of dif- ferent designs, we deployed four radically different traps for 48 days in the Santa Barbara Basin. The designs used were: (1) paired cones, (2) folding box or "suitcase", (3) cylinder, and (4) closing box (Fig. 1). In addition to the trap deployment, cur- rent meters and a recording nephelometer were deployed for the duration of the experiment. The Santa Barbara Basin was chosen for the sediment trap intercomparison because previous studies of sediment flux to the seafloor and sedi- ment accumulation provide a data base which could be helpful in the interpretation of our re- 0012-821X/81/0000-0000/$02.50 © Elsevier Scientific Publishing Company