This is the Tantalus Creek discharge graph at Norris Geyser Basin in Yellowstone, Wyoming. The prominent spike at center-right is an increase in stream water volume from a Steamboat Geyser major eruption. It erupted starting at 9:40 PM on 11 September 2019. Reported lag times between Steamboat eruptions and discharge spikes at the Tantalus Creek recording station range from less than an hour to about 1.5 hours.

Steamboat is the world's tallest geyser. Its eruptions are normally unpredictable - it can go years or even decades without erupting. Steamboat entered an exciting active phase in spring 2018. From fall to the end of 2018, Steamboat continued to erupt about once every 5 to 9 days. 2018 set the record for the most active year ever, with 32 eruptions. 2019 broke that record - this is the 35th eruption of Steamboat Geyser this year. In January 2019, intervals (= eruption start to eruption start) were about 9 to 11.5 days. In February 2019, intervals were about 7 to 9.5 days. March 2019 intervals were about 6 to 8 days. In April 2019, intervals were 14 days and 17 days. Longer intervals between Steamboat eruptions are known to occur during "disturbances" at Norris Geyser Basin (this also happened in summer 2018). In May 2019, after the disturbance ended, intervals were 7 days, 5 days, 5.5 days, 6.8 days, 7 days, and 5 days. In June 2019, intervals were 5 days, 5.5 days, 3 days, 3.4 days, 4.5 days, and 5.5 days. ~Three day intervals are remarkably short for Steamboat Geyser. In July 2019, intervals were 5 days, 6.75 days, 7.5 days, 5.8, and ~6.25 days. In August 2019, intervals were 13.6 days, 7.6 days, and 6.9 days. The two week long interval in August was due to another Norris Basin disturbance. In September 2019, intervals were ~6.7 days and 8.8 days.

Photo album of Steamboat's 4 June 2018 eruption: <a href="https://www.flickr.com/photos/jsjgeology/albums/72157670618318878">www.flickr.com/photos/jsjgeology/albums/72157670618318878</a>

Video of Steamboat's 4 June 2018 eruption: