CALIBRATIONCalibration of the relationship between contemporary environmental values (seasurface temperature) and proxy data (percentage of Globegerina in surficial sediments) permits us to estimate the past temperature when proxy data were deposited. The line in the graph of seasurface temperature versus Globegerina percent (below) is described by two points (X,Y) 0,0 and 40,20 (Globegerina %, oC ). A fossil sample contains 25% Globegerina, what was the seasurface temperature at the time (and place) that sample was deposited? Calibration procedure: The transfer function for this problem is of the form Y = bX + c where
Therefore, the transfer function is Y = 0.5 * X + 0 (past Sea Surface Temperature equals ½ of the Globegerina percent) For example, for 25% Globegerina the seasurface temperature is 12.5 ^{o}C 12.5 ^{o}C = 0.5 * 25 + 0 For the following five calibrations sets, defined by points 1 & 2, calculate the transfer function (Y = bX + c) by first finding the slope of the line (b) and the Yintercept (c). Then, calculate the past temperature implied by the percentage of Globegerina in a fossil sample. Hand in a table showing the five pairs of points, b, c, the calculate temperature, and your calculations.
