Changes in Dimensions of Glaciers

The United States Geological Survey (USGS) monitors a series of glaciers in Washington and Alaska (see map below) to determine rates of change in dimensions and mass of these features.

Every year the USGS determines mass balance (ice production - ice loss) for these glaciers. These data are shown in the table below.

Plot these data on the set of axes provided here. You can print these or your instructor may provide you with a hard copy version before you begin.

Examine the data you just plotted and try to determine whether there is a trend in the data over time (Does the magnitude of the mass balance change over the years?). The first step is to draw a straight line through the data (best fit by eye), which indicates the general trend over time. If done properly, there should roughly be equal numbers of points above as well as below your line, and some points should fall on the line.