Old Faithful’s blistering geyser cone once had trees growing in it, experts discover

Old Faithful at Yellowstone National Park spews 204-degree water, yet recently discovered evidence proves the geyser’s deadly cone once hosted a growth of trees, according to the U.S. Geological Survey.

That is impossible ... except in one instance, experts say.

“There was a time when Old Faithful wasn’t faithful at all,” Yellowstone Volcano Observatory scientist Mike Poland says in a video posted Dec. 2 on Facebook.

“Now, we know that trees are not going to be growing on a geyser, because of all that hot water. It kills them. So those trees must have grown at a time when Old Faithful was dormant.”

Multiple “mineralized” tree specimens were found and analyzed, giving scientists a rough estimate they lived 600 to 800 years ago, he said.

“The geyser must not have erupted at all. This actually corresponds to a period of drought in the region. In fact, drought throughout much of the western United States. ... So during periods of heavy drought, when water levels perhaps are quite low beneath Old Faithful, the geyser doesn’t erupt.”

The popular geyser gets its name from the fact that it faithfully erupts about once every hour and a half, Poland says. However, even that has changed over time. It was erupting every 60 to 70 minutes when “first scientifically described in the 1970s,” he said.

The time started to lengthen in the 1950s, after a series of earthquakes that included a 7.3 magnitude quake in 1959, he said.

Old Faithful is estimated to have erupted one million times since being discovered in 1872, according to Yellowstonepark.com. The water in its bowels “exceeds” 400 degrees, but cools by about 200 degrees by the time it spews from the ground (to the glee of waiting tourists), the National Park Service says.

The geologically volatile region sees 100 earthquakes a month on average, Poland says in the video.

Monthly data also show the caldera area around Old Faithful has been sinking at a rate of about an inch a year since 2015, he said.

This story was originally published December 4, 2020 at 1:15 PM with the headline "Old Faithful’s blistering geyser cone once had trees growing in it, experts discover."