The Echinus Geyser in Yellowstone National Park is active again after more than five years of quiet.
Scientists from the US Geological Survey (USGS) shared the exciting news in early March 2026.
This special geyser, known as the world’s largest acidic one, sits in the Norris Geyser Basin and last erupted in December 2020.
WHAT IS ECHINUS GEYSER?
The Echinus Geyser is a hot spring that shoots hot water and steam into the air during eruptions. Its water is very acidic, which creates bright red, orange, and yellow colours around the edges from minerals like iron, aluminium, and arsenic.
The geyser has a large pool, about 20 meters wide, with a spiky rim made of silica. When it erupts, it can send water up to 20–30 feet high for 2 to 3 minutes.
Visitors sometimes describe the bursts as powerful and beautiful, though the water can carry a strong sulphur smell.
WHEN DID ECHINUS GEYSER ERUPT?
Officials picked up activity around the hot spring in early February 2026. This is the first time the geyser has erupted.
The first eruption happened on February 7, with more on February 9, February 12, and February 15.
From February 16 onwards, eruptions came every 2 to 5 hours. By late February, the geyser had erupted around 40 times.
Scientists track the eruptions using temperature sensors in the run-off channel, which show clear spikes when hot water surges and erupts. This pattern looks similar to one seen in late 2017.
WHY THE LONG BREAK?
Geysers in Yellowstone work because of underground heat from the area’s volcanic system.
In simpler words, hot rocks warm groundwater, building pressure until it explodes upward as an eruption.
Echinus has irregular cycles, meaning it can be very active for a while, then go quiet for years. The recent return is a natural part of how these features behave in Norris Geyser Basin.
Nearby Steamboat Geyser, the tallest active geyser in the world, also had an eruption in late February 2026.
The eruption of geysers in the national park made locals wonder whether it was a troubling sign, but USGS experts confirmed that Yellowstone’s overall activity remains at normal, background levels.
There were only 74 small earthquakes in February, with the biggest at a mild magnitude of 2.4. Ground movement has paused in some areas.
The geyser eruptions are just part of the park’s normal hot water system, not linked to any volcanic unrest or danger.
Officials have stressed that these events are spectacular but safe and expected in the park.
This lively show from Echinus reminds people why Yellowstone draws millions of visitors each year, as its unique hot springs and geysers offer a rare glimpse into Earth’s powerful inner heat.
Park staff continue to monitor the area closely and share updates, so everyone can enjoy the display safely.
