Rob and Jennifer Gunderson were visiting Yellowstone National Park for their anniversary, and couldn’t believe their eyes when they saw people walking right up to the 1,000-pound animal.

A 53,000-pound vibroseis truck, with a hydraulic vibration plate that creates signals like tiny earthquakes. The truck is parked at a roadside pullout near the Continental Divide in Yellowstone ...

A seismic survey reveals a magma cap 2.5 miles under Yellowstone, acting as a pressure-release lid and reducing the risk of a super volcano eruption.

A seismic survey reveals a magma cap 2.5 miles under Yellowstone, acting as a pressure-release lid and reducing the risk of a super volcano eruption.

A seismic survey reveals a magma cap 2.5 miles under Yellowstone, acting as a pressure-release lid and reducing the risk of a super volcano eruption.

A seismic survey reveals a magma cap 2.5 miles under Yellowstone, acting as a pressure-release lid and reducing the risk of a super volcano eruption.

A seismic survey reveals a magma cap 2.5 miles under Yellowstone, acting as a pressure-release lid and reducing the risk of a super volcano eruption.