Uploaded August 2021 | Updated September 2026, 2 weeks ago
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Fan Geyser (2018)
Geysers are hot springs that episodically erupt columns of water. They occur in few places on Earth. The highest concentration of geysers anywhere is at the Yellowstone Hotspot Volcano (northwestern Wyoming, USA).
Fan Geyser is a major feature in the Morning Glory Group of Yellowstone’s Upper Geyser Basin. It is located on the northeastern bank of the Firehole River, just downstream from Mortar Geyser. Fan Geyser consists of a series of vents oriented along a northeast-southwest fracture zone that goes through nearby Spiteful Geyser. From southwest to northeast, the principal vents of Fan Geyser are: River Vent, High Vent, Gold Vent, Angle Vent, Main Vent, and East Vent.
Eruptive activity at Fan Geyser currently takes several forms: "garbage", regular cycles, event cycles, and (major) eruptions. "Garbage" refers to disorganized low spouting from Fan's various vents. Regular cycles involve organized low spouting/splashing that starts with River Vent, progresses to High Vent and Gold Vent, and continues to Angle Vent. Eventually, the low spouting ends. Event cycles are characterized by slightly more unusual activity, including one or more pauses and resumptions in River Vent’s erupting, more energetic and higher spouting from High Vent, Gold Vent, and Angle Vent, and small splashing in the Main Vent. Major eruptions of Fan Geyser are almost always in concert with nearby Mortar Geyser (there have been exceptions in the past). Eruptions occur after an energetic event cycle and involve high spouting from East Vent, Main Vent, and all other vents. Eruption columns extend in various directions, resulting in a fan-like spray. Spouting often reaches the trail or past the trail. Eruptions are about 30 to 40 minutes in duration, and include one or more relatively brief pauses.
Clips 1-10 - Fan Geyser’s 1:14 PM-onward “minor eruption” on 2 August 2018. This event has also been characterized as a long, false lock.
Clips 11-15 - Fan Geyser’s 5:50 PM-onward event cycle on 14 August 2018. These clips are late in the cycle, from 7:00 to 7:07 PM. (time stamp 3:27)
Clips 16-17 - Fan Geyser’s 12:28 to 1:18 PM event cycle on 6 June 2018. These clips are late in the cycle, from 1:17 to 1:18. (time stamp 5:22)
Clips 18-27 - Fan Geyser’s 1:18 to 1:52 PM major eruption on 6 June 2018. (time stamp 5:47)
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Fan Geyser (2018)
Geysers are hot springs that episodically erupt columns of water. They occur in few places on Earth. The highest concentration of geysers anywhere is at the Yellowstone Hotspot Volcano (northwestern Wyoming, USA).
Fan Geyser is a major feature in the Morning Glory Group of Yellowstone’s Upper Geyser Basin. It is located on the northeastern bank of the Firehole River, just downstream from Mortar Geyser. Fan Geyser consists of a series of vents oriented along a northeast-southwest fracture zone that goes through nearby Spiteful Geyser. From southwest to northeast, the principal vents of Fan Geyser are: River Vent, High Vent, Gold Vent, Angle Vent, Main Vent, and East Vent.
Eruptive activity at Fan Geyser currently takes several forms: "garbage", regular cycles, event cycles, and (major) eruptions. "Garbage" refers to disorganized low spouting from Fan's various vents. Regular cycles involve organized low spouting/splashing that starts with River Vent, progresses to High Vent and Gold Vent, and continues to Angle Vent. Eventually, the low spouting ends. Event cycles are characterized by slightly more unusual activity, including one or more pauses and resumptions in River Vent’s erupting, more energetic and higher spouting from High Vent, Gold Vent, and Angle Vent, and small splashing in the Main Vent. Major eruptions of Fan Geyser are almost always in concert with nearby Mortar Geyser (there have been exceptions in the past). Eruptions occur after an energetic event cycle and involve high spouting from East Vent, Main Vent, and all other vents. Eruption columns extend in various directions, resulting in a fan-like spray. Spouting often reaches the trail or past the trail. Eruptions are about 30 to 40 minutes in duration, and include one or more relatively brief pauses.
Clips 1-10 - Fan Geyser’s 1:14 PM-onward “minor eruption” on 2 August 2018. This event has also been characterized as a long, false lock.
Clips 11-15 - Fan Geyser’s 5:50 PM-onward event cycle on 14 August 2018. These clips are late in the cycle, from 7:00 to 7:07 PM. (time stamp 3:27)
Clips 16-17 - Fan Geyser’s 12:28 to 1:18 PM event cycle on 6 June 2018. These clips are late in the cycle, from 1:17 to 1:18. (time stamp 5:22)
Clips 18-27 - Fan Geyser’s 1:18 to 1:52 PM major eruption on 6 June 2018. (time stamp 5:47)
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