Echinus Geyser, Acid geyser in Norris Geyser Basin, Yellowstone National Park, Wyoming.
Echinus Geyser is located in Norris Geyser Basin in Yellowstone National Park and erupts with acidic water, shooting steam and water up to 40 to 60 feet high. The mineral cone has a distinctive spiky surface that stands out visually from other geysers in the area.
Before 1998 this geyser erupted regularly, but its pattern shifted dramatically afterward. Since then it has become unpredictable with extended periods of quiet between eruptions.
The name comes from the spiky mineral deposits that form the geyser cone, resembling sea urchin spines. You can observe this distinctive form when you visit the site.
Activity here is difficult to predict, so ask park rangers for current information before planning your visit. Bring comfortable walking shoes since you will need to hike from the parking area to the viewpoint.
The water here is extremely acidic with a pH between 3.3 and 3.6, making it the largest acid-water geyser on Earth. This acidic chemistry prevents the living organisms found in other geysers from thriving here.
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