Richard A. Schwartzlose

Migrant Sound Scatterers: Interaction with the Sea Floor.

Studies on the coast of Baja California show that oceanic zooplankters carried into shallow water provide abundant food for resident predators. The vertically migrating zooplankters apparently are vulnerable when they encounter the sea floor in shoal areas. This ecologically significant mechanism may be of importance to fisheries and military operations.

Transient Circulation Event near the Deep Ocean Floor.

On 24 January 1968, a transient deep-circulation event was recorded by a triangular array of autonomous current recorders installed 3 meters above the bottom at two of the three positions and at intervals of 3 to 1000 meters above the bottom at the third position in a depth of 3950 meters above the relatively smooth floor of the eastern North Pacific. The event interrupted a 24-hour record of relatively steady but peculiar conditions, lasted for about 1� hours, and was followed by current directions and speeds that greatly differed from those of the initial period. The event occurred over a volume of the sea of at least 2 kilometers in horizontal dimensions and 1 kilometer thick. Associated with the event were many small clockwise-rotating features extending from 3 to at least 1000 meters above the bottom and a rapidly increasing current velocity at 1000 meters. The event was probably local and may have involved convective motion, internal waves, and the passage of front. Some of the changes in horizontal velocity may have resulted from the combined effects of upwelling and the earths rotation.

A Camera System For The Observation Of Deep-Sea Marine Life

A deep-sea camera system has been developed for observing events on the deep ocean floor for time periods as long as 100 hours. This lightweight system has principally been employed to observe deep benthic organisms. In this use, it freely descends to the ocean floor, where it is maintained by a ballast weight surrounded by bait. Lured into the field of view of the camera by the bait, the creatures are photographed at preset intervals. At a preselected time, the camera system is separated from the ballast weight and ascends to the surface for recovery. Photographs have shown large numbers of active organisms to depths of 20,000 feet, including large predators.

Measurements of the California current in March 1958

Abstract Two sets of drogues were placed approximately normal to the usual flow and followed for one and three days respectively. The first set, which extended thirty miles offshore, drifted south-eastward. The second set, which extended from thirty to seventy miles offshore, also moved south-eastward but with considerable variation in speed and direction along the line. In the latter set two rapidly moving streams appeared with a body of slower water between.

Scale errors on oceanographic mercurial thermometers

Abstract Errors of more than 0·01°C due to the method used in engraving scales, may be common in oceanographic mercurial thermometers. In this study 8 non-reversing thermometers were used; out of these, the spacing between scribed lines was measured very accurately on 4 thermometers. Two of the thermometers had significant scale errors. New correction curves were made for the thermometers, using the scale measurement information. All the thermometers were then intercalibrated. It would appear that after this treatment any of these thermometers could be used as precision laboratory standards.