This report presents statistical data on geophysical activity in 1979. The data were compiled from survey questionnaires that were completed by more than 500 companies, contractors, government agencies, and institutions throughout the free world. We have gathered information from users of geophysical techniques in the areas of petroleum, mining, geothermal, and groundwater exploration; and from those who employ geophysical methods in engineering surveys, oceanography, and research. Data were gathered on airborne, drill hole, land, and marine geophysical surveys. Statistics were compiled on miles of coverage, drill hole footage, time spent in crew months or man months, and acquisition cost.