Exploration
By 1979, Herb and Jan Conn had discovered, named, and mapped more than 64 miles (103 km) of passages. Although they largely retired from caving by the early 1980s, exploration has continued unabated. Because the areas being explored take many hours to reach, explorers now sometimes camp in the cave during expeditions of as long as four days. The cave is mapped by traditional survey techniques, using compass, clinometer and today with lasers instead of tape measures.
Its 157.36 mi (253.25 km) of mapped passageway make Jewel Cave the second longest cave in the world, after Mammoth Cave in Kentucky, at 390 mi (630 km).
The discovered areas in the cave account for only about 2% of the estimated total air volume of the cave. The cave volume is estimated by measuring the amount of air that the cave "exhales" when the outside air pressure drops and "inhales" when the outside air pressure rises.
Read more about this topic: Jewel Cave National Monument
Famous quotes containing the word exploration:
“Typography tended to alter language from a means of perception and exploration to a portable commodity.”
—Marshall McLuhan (1911–1980)
“I call her old. She has one family
Whose claim is good to being settled here
Before the era of colonization,
And before that of exploration even.
John Smith remarked them as he coasted by....”
—Robert Frost (1874–1963)
“The future author is one who discovers that language, the exploration and manipulation of the resources of language, will serve him in winning through to his way.”
—Thornton Wilder (1897–1975)