In this activity, students manipulate and graph data collected by the research vessel, JOIDES Resolution, to determine whether sediment thickness located near the Juan de Fuca Ridge supports the concept of seafloor spreading. Teachers can choose between two formats: a Google Earth based version or a pen and paper one. In the former version, students will be tasked with finding and recording the pertinent data before calculating sediment and basalt depths. In the latter, students are provided with data but must still do all depth calculations. In both formats, students will manually draw their graphs. The Teacher Guide provides an answer key for the calculations, graph and short answer questions. The authors state that the activity can be completed in one class period; however, given the amount of calculations and graphing, this is an optimistic estimate at the middle school level.