The U.S. Geological Survey has an extensive database of lava-related events in Hawaii. One hundred of the best images have been assembled on a web page and placed on a DVD. These were...
...selected from the collections of the Hawaiian Volcano Observatory as enduring favorites of the staff, researchers, media, designers, and the public over time. They represent photographs of a variety of geological phenomena and eruptive events, chosen for their content, quality of exposure, and aesthetic appeal. The number was kept to 100 to maintain the high resolution desirable.
In the photo above a pair of "concerned scientists" decide to run from a "...surging ‘a‘a flow in Royal Gardens. The top of an ‘a‘a flow rides on the underlying mass and rolls over it like a tractor’s tread, advancing to the front of the flow."
Link, via. Photo by J.D. Griggs, 7/2/83, JG2514 (click to enlarge).