Daily Journal

December 4, 2004: Scientists and Their Tools

On December 3, we lowered a CTD, an instrument that measures conductivity, temperature, and depth as it collects water samples. On this expedition, the scientists are specifically interested in measuring amounts of barite in the sea water.

What is barite and why are scientists interested in it? Barite is a mineral that has commercial uses; however, more importantly, barite serves as a record of changes in the ocean. Understanding how barium moves through cold seeps is the key to understanding how oceans change. Studying the record of how oceans have changed in the past helps scientists make predictions about how climate changes will affect oceans in the future. For example, California current has great economic value to the fishing industry. Scientists look at how climate changes like global warming might affect the productivity of these ocean resources.

Environmental Science

Question 1 and related activities: In pairs or groups, make a list of types of fish or other seafood that is available in your markets or restaurants. Choose 5 to list on a chart. List the names in column one. Using the Internet or other resources, fill in column two of the chart listing where this seafood comes from. In column three, list the habitat conditions that are necessary e.g., temperature, salinity, amount of oxygen. In the fourth column, list threats to their survival, such as warming of the ocean temperatures, or over fishing.

Math Catch of the Day:

The CTD is attached to the bottom of the rosette. There are 24 one liter bottles on the rosette that collect water samples at various depths.

Math question: We need 408 liters of water to conduct research on. How many times do we need to cast the rosette to get 408 liters?

top left: CTD
top right: CTD deployment
above left: Collecting water samples from the rosette
above right: CTD sensors under the rosette

Next episode: Recovering the Mooring

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