Uploaded March 2026 | Updated September 2026, 2 weeks ago
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UNNG-FLD-18 (unnamed geyser north of West Flood Geyser)
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 in northwestern Wyoming, USA.
“UNNG-FLD-18” refers to an unnamed geyser (UNNG) about 38 meters north of the center of West Flood Geyser in the Flood Group of Yellowstone’s Midway Geyser Basin. The feature is located on the western bank of the Firehole River, at 44° 31’ 15.65” North latitude, 110° 49’ 46.74” West longitude. The vent number “18” is from Wolf & Paperiello (1986), Report on Lesser Known Thermal Units of Yellowstone National Park, 1981-1985 (see pages 451 and 455). This is their description of the feature:
“18 - UNNG. An old established longitudinal vent in a narrow raised sinter cone right at the edge of the Firehole River. As observed on October 23, 1984, it was exhibiting definite geyser activity. Its eruptions would consist of a series of spurts reaching 1.5 feet. Its duration was about 15 to 45 minutes, but it started and ended very slowly - its spurts being widely spaced at these times. During its highest activity spurts would come every few seconds.
Time Duration Interval Pause
12:00 40 minutes
12:48 15 minutes 48 minutes 8 minutes
13:16 28 minutes 28 minutes 8 minutes
13:51 35 minutes 7 minutes
There is a steam vent directly above this geyser near the top of the river bank.”
All clips - unnamed geyser in the afternoon of 16 June 2023.
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UNNG-FLD-18 (unnamed geyser north of West Flood Geyser)
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 in northwestern Wyoming, USA.
“UNNG-FLD-18” refers to an unnamed geyser (UNNG) about 38 meters north of the center of West Flood Geyser in the Flood Group of Yellowstone’s Midway Geyser Basin. The feature is located on the western bank of the Firehole River, at 44° 31’ 15.65” North latitude, 110° 49’ 46.74” West longitude. The vent number “18” is from Wolf & Paperiello (1986), Report on Lesser Known Thermal Units of Yellowstone National Park, 1981-1985 (see pages 451 and 455). This is their description of the feature:
“18 - UNNG. An old established longitudinal vent in a narrow raised sinter cone right at the edge of the Firehole River. As observed on October 23, 1984, it was exhibiting definite geyser activity. Its eruptions would consist of a series of spurts reaching 1.5 feet. Its duration was about 15 to 45 minutes, but it started and ended very slowly - its spurts being widely spaced at these times. During its highest activity spurts would come every few seconds.
Time Duration Interval Pause
12:00 40 minutes
12:48 15 minutes 48 minutes 8 minutes
13:16 28 minutes 28 minutes 8 minutes
13:51 35 minutes 7 minutes
There is a steam vent directly above this geyser near the top of the river bank.”
All clips - unnamed geyser in the afternoon of 16 June 2023.
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