IGY Bulletin, Number 9, March 1958 - Cruise of the Brown Bear

The ocean deeps are some of the most remote places on the Earth's surface (take the water out of the ocean, and the seafloor is the surface). Both the nature of the seafloor itself and the currents of  the ocean waters were of interest during the IGY. This article describes the cruise of the oceanographic vessel Brown Bear, of the University of Washington. 

R/V Brown Bear, photo provided by V. Lundquist, from NOAA Alaska Fisheries Science Center (https://www.ocean.washington.edu/story/School_History)

In the beginning of the IGY, the Brown Bear made investigations at 36 oceanographic stations in the Gulf of Alaska, the Bering Sea, and parts of the Northeast Pacific, as shown in the map below from the Bulletin article. The proposed cruise for 1958 is also shown, as are stations occupied by the Carnegie in 1929. The Carnegie  (you should read the fascinating article in the link) was a brigantine nonmagnetic yacht used to investigate the Earth's magnetic field for the Carnegie Institution's Department of Terrestrial Magnetism. That 1929 voyage was its last, as it exploded and sank while anchored in Samoa that November.

The Brown Bear's measurements were to look at both latitudinal and vertical movement of waters in the ocean, and the factors that affected them. According to the National Oceanographic and Atmospheric Administration (NOAA):

Differences in water density, resulting from the variability of water temperature (thermo) and salinity (haline), also cause ocean currents. This process is known as thermohaline circulation. In cold regions, such as the North Atlantic Ocean, ocean water loses heat to the atmosphere and becomes cold and dense. When ocean water freezes, forming sea ice, salt is left behind causing surrounding seawater to become saltier and denser. Dense-cold-salty water sinks to the ocean bottom. Surface water flows in to replace the sinking water, which in turn becomes cold and salty enough to sink. This "starts" the global conveyer belt, a connected system of deep and surface currents that circulate around the globe on a 1000 year time span. This global set of ocean currents is a critical part of Earth’s climate system as well as the ocean nutrient and carbon dioxide cycles.

Ocean circulation patterns are also nicely explained and depicted in this Ted-Ed video, Surface currents are the focus of the first half of the video, while deep currents are described in the second half.

The major objectives of the Brown Bear's 1957 cruise were: to gather data for a north-south profile of water properties (temperature and chemistry) extending from the surface to the ocean bottom; and for a preliminary survey of ocean water circulation in the Aleutians. Hauls of marine organisms were also made at various depths. Deep waters were dated using carbon-14 methods. The article goes on to cite specific preliminary findings. 

It turns out that I have a relevant first day cover in my collection for today's post.  It's a first day of issue cover of the U.S. IGY stamp, with a cachet of the R.V. (research vessel) Brown Bear. And, it is addressed to Richard Fleming (1909-1989), who was the director of the Department of Oceanography at the University of Washington.

FDC US141 from my collection

Richard Fleming (School of Oceanography, Univ. of Washington)