Lake Superior seismic experiment

During the Lake Superior seismic experiment, an International Upper Mantle cooperative program in July 1965, the U. S. Geological Survey provided a total of 8 mobile seismic-recording systems. For the first phase of the experiment the systems were arranged in two groups of 4; one group at the western end of the lake near Duluth and the other was on the Keweenaw Peninsula. During the last three days of the experiment all 8 systems were located at various positions in parts of Wisconsin and Minnesota.

Selected sections of 500 seismograms are presented.