Geologists walk over the surface of the flow to track surface break...
![HVO geologists walk over the surface of the flow to track surface b...](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/vhp_img3912.jpg?itok=bpAplYL9)
Detailed Description
HVO geologists walk over the surface of the flow to track surface breakouts along a portion of the flow margin, about a kilometer (0.6 miles) upslope of the flow front.