Echinus Geyser


Echinus (e-KI-nus) Geyser is named for its deposits, which look like the spines of echinoderms such as sea urchins or sea stars. It was a perennial crowd-pleaser which typically erupted every 35 to 75 minutes. Late in 1998 this geyser altered its interval and now erupts only a few times per day at best. Its pool fills gradually with water; then suddenly, bursts of steam and water explode 40 to 60 feet (12 to 18 m) skyward. Eruptions usually last about 4 minutes but in the past major eruptions have lasted as long as 118 minutes. The major eruptions were believed to be caused by a secondary water source which has mysteriously vanished. There has not been a major eruption in 3 years. In late 1998 Echinus' performance diminished and became erratic. As of early-2000 its eruptions remain unpredictable. Echinus is the largest acid-water geyser known. Its waters are almost as acidic as vinegar with a pH ranging from 3.3 to 3.6 . Acid geysers are extremely rare with the majority of the planet's total being found here at Norris Geyser Basin.

*Adapted from the NPS Norris Geyser Basin Trail Guide and the Norris Interactive Map

Feature Type


Inventory ID



Latitude: 44.72206
Longitude: -110.7021
Survey Date: August 11, 1998

Geographic Area: Gibbon Canyon
Thermal Region: Norris Geyser Basin
Thermal Complex: Back Basin
Ranger District Contact: Norris District, Al Miller (307) 344-2501


Nordstrom, D. Kirk
Takacs-Vesbach, Cristina

Feature Data

Data Source Supplied By Sample Date Temp Vent Temp pH Cond Extended Data
Participant USGS 6/1/1971 -- -- -- -- Yes Details
Participant USGS 6/1/1975 -- -- -- -- Yes Details
Park 8/11/1998 80.3°C 0°C 3.63 1300 µS/cm No
USGS 5/31/2003 72.7°C -- 3.58 1140 µS/cm Yes Details
Participant Takacs-Vesbach, Cristina 6/4/2003 73°C -- 3.61 1175 µS/cm Yes Details
USGS 9/2/2003 72°C -- 3.55 1142 µS/cm Yes Details
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