Geologists conduct a VLF (very-low frequency) survey to measure the...

Detailed Description
HVO geologists conduct a VLF (very-low frequency) survey to measure the rate of lava flowing through the lava tube on the June 27th lava flow.
HVO geologists conduct a VLF (very-low frequency) survey to measure the rate of lava flowing through the lava tube on the June 27th lava flow.