This blowhole, a crevice in the earth's crust that appears to breathe, is one of several in the Wupatki area. It connects to an underground passage of unknown size, depth, and complexity called an earthcrack. Earthcracks resulted from earthquake activity in the Kaibab Limestone bedrock and have enlarged over time. Archaeologists have found no evidence of prehistoric structures or uses at the blowhole, and its connection to Wupatki Pueblo remains unknown. Today, the Hopi, descendants of these early people, call the blowhole the breath of "Yaaponsa," the wind spirit, and they and other American Indians attach spiritual significance to such features. Like other caverns, this passage responds to changes in outside barometric pressure, and the breathing effect can be especially dramatic when a blowhole opening is small.