Overview
- After being largely quiet since 2020, Echinus produced eruptions on Feb. 7, 9, 12 and 15, according to USGS monitoring.
- Beginning Feb. 16, activity shifted to eruptions every 2–5 hours reaching about 20–30 feet for 2–3 minutes, then tapered by late February.
- Recent temperature logs show surge spikes without eruptions, and officials say a continued run into summer is unlikely.
- YVO tracks the geyser with an outflow temperature probe where ~70°C spikes indicate eruptions and 40–50°C spikes indicate non-eruptive surges.
- As the world’s largest acidic geyser in Norris Geyser Basin, Echinus has vinegar-like acidity that creates red mineral rims, and visitors are urged to stay on boardwalks because waters can approach 200°F as Yellowstone remains at background activity levels.