Blowhole (geology)

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In geology, a blowhole is a cavity formed in the ground at the inland end of a sea cave. When waves enter the mouth of the cave they will be funneled up towards the blowhole, which can result in quite spectacular splashes if the geometry and state of the weather are appropriate.

Also the name of a rare geologic feature in which air is either blown out or sucked into a small hole at the surface due to pressure differences between a closed underground cavern system and the surface. Some of the most famous are the blowholes near Flagstaff, AZ US. It is estimated that the closed underground passages have a volume of at least 7 billion square feet. Wind speeds can approach 30 miles per hour.

[edit] See also

• Category:Blowholes - a list of blowholes.