GeoGirls use ground-penetrating radar
![7 teen girls and 1 woman outdoors, examining instrument on 4 wheels. snow-covered volcano in background.](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/thumbnails/image/GPR_IMG_0529.jpg?itok=EZcGdyqR)
Detailed Description
GeoGirls use ground-penetrating radar to locate rock and ash layers from past eruptions at Mount St. Helens (Mount Adams is pictured in the background).
GeoGirls use ground-penetrating radar to locate rock and ash layers from past eruptions at Mount St. Helens (Mount Adams is pictured in the background).