Carbonates and Climate

Today we went to the chemistry lab and learned how to measure the percentage of carbonate in the sediments of a core. The percentage of carbonate in a core sample is determined by using an instrument called a coulometer. A standardized sample, made of 100% calcium carbonate, was run first for calibration. Then a small sample from a core was run and about ten minutes later I had the percentage carbonate in the sample. The coulometer essentially titrates the sample but does the titration automatically once the sample is readied. It was very interesting to see how the samples are prepared, logged into the computer, and the results displayed. The amount of carbonate in a sample allows scientists to learn about the climates of the past.

Another group of teachers from the School of Rock worked in another area of the laboratory to determine carbonate percentages using a different method. They were testing a procedure that would allow teachers to do the carbonate measure in a typical classroom where a coulometer would not be available. Later in the day, we compared and discussed the results from both methods. The results did not correlate as well as was hoped, but we did determine that the method worked well enough for students to learn how to test soils for carbonate. With a few modifications, we think that the method can be improved.

We ended the day with a video conference with two schools in Japan. Two of my fellow teachers are from Japan and they taught a lesson about the JOIDIES Resolution. Students from Japan asked questions and were guided by their own teacher in Japan. It was an exciting event.