Logging Requirements
Send me an email or message with:
- The text "GCZ5W1 Wupatki Pueblo Blowhole" on the first line.
- The number of people in your group.
- The direction air was flowing with an explanation as to why.
- Post a photo showing the direction of the air flow (use hair, paper, shirt, etc.), including your GPSr if possible.
- From the sign, what is the name given to the blowholes by the local tribes?
As you walk down the path and through the pueblo you will see black basalt from the eruption of Sunset Crater (See Sunset Crater Lava Flow Trail earthcache) and the Moenkopi Formation (See Wupatki Ripple Marks earthcache).
At the end of the trail you will find a grated hole in the ground. This small hole is connected to a network of cavities in the Kaibab Formation (See Walnut Canyon, Citadel Sink, and Lomaki and Box Canyon Pueblos earthcaches). The initial cracks are thought to have been formed by compression during uplift of the Rocky Mountains and the subsequent release of pressure as overlying rocks were eroded away.
They have since widened from dissolution by slightly acidic rainwater and ground water running into the crack. As these waters move through the rocks they slowly dissolve the limestone of the Kaibab Formation forming a network of cavities. The full extent of the network of cavities has not been investigated.
The blowhole can actually either exhale or inhale air depending upon the difference between air temperature and atmospheric pressure on the surface and the conditions inside the cavities. If the air outside is cooler than inside, air will rush into the hole because the air outside is more dense. The air will blow out of the hole if the air outside is hotter than inside because the air outside is less dense. High and low pressure weather systems will also have the same effect. I caught the blowhole when air was rushing out.
Placement approved by the Wupatki National Monument. Editorial review provided by Sara Hanson. The above information was compiled from the following sources:
- Hanson, Sarah L. 2003, Roadside Geology: Wupatki and Sunset Crater Volcano National Monuments, Arizona Geological Survey, Down-to-Earth 15
- NPS Informational Signs