Blowhole (geology)

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In geology, a blowhole is a cavity located at the end of a sea cave which exits above the cave. When a wave enters the mouth of the cave it will be funneled up towards the blowhole,which can result in quite spectacular blasts of water from the top of the blowhole if the geometry of the cave and blowhole 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, Arizona, USA. It is estimated that the closed underground passages have a volume of at least seven billion cubic feet. Wind speeds can approach 30 miles per hour.

The Kiama Blowhole (Kiama, NSW, Australia) is believed to be the world's largest blowhole.

[edit] See also

• Category:Blowholes - a list of blowholes.