A foot floating in a Yellowstone hot spring leaves more questions than answers

A foot found floating in a hot spring in Yellowstone National Park has been linked to a July 31 death.

On August 16, a park employee found the foot, still encased in a shoe, at Abyss Pool, one of Yellowstone’s deepest hot springs. In a statement today (August 19), authorities said the foot is linked to an incident involving a single individual on the morning of July 31 and they do not suspect foul play. They did not explain why they did not suspect foul play, nor identify the deceased person. An investigation is underway.

Yellowstone is dotted with geothermal springs, many of which are hot enough to scald a person. The mineral crusts around the springs may seem solid but crack under the weight of someone stepping on them. In 2016, a 23-year-old man from Oregon died after slipping in a hot pool at Norris Geyser Basin while trying to swim in an enclosed area. The pool was over 212 degrees Fahrenheit (100 degrees Celsius) and very acidic, according to USA today (opens in a new tab). Park officials saw the man’s body floating in the hot spring the day he died, but were unable to immediately recover it. When they returned the next day, they could not find the remains.

“Evidence suggests that the extreme heat and acidity of the water rapidly dissolved his body in the hot spring,” according to a park report released in response to a Freedom of Information Act request filed by KULR-TV in Billings. , Montana.

A map of Yellowstone hot springs by type.

A map of Yellowstone hot springs by type. (Image credit: USGS Scientific Investigations Report 2017–5022–P)

The pool where the Oregon man died is an acid sulfate hot spring. These hot springs, most commonly found in the northeast part of the park, are heated by acidic steam so strong that it can eat away rocks and minerals around the springs, according to the United States Geological Survey. Mud Volcano and Artists Paint Pots, two popular tourist sites in the park, are both acid sulfate features.

However, many pools in Yellowstone are alkaline or basic. The pH scale runs from zero to 14, with zero being the most acidic, 7 being neutral, and 14 being the most basic. Abyss Pool is one of the park’s alkaline pools, with a pH of 8.65, according to an article published in the book “Mechanisms and phylogeny of mineralization in biological systems: Biomineralization ’90(Springer Science & Business Media, 2012). A pH of 8.6 is more basic than most seawater, but less basic than baking soda. Swimming pools like Abyss Pool get their alkalinity from fluids that carry the chloride from deep below the surface.

Abyss Pool is located in the West Thumb Geyser Basin near Yellowstone Lake. According to the National Park Service, it can reach 16 meters deep and around 140 F (60 C).

It is unclear whether the person at the source became disabled from the hot water or died in some other way. It is not surprising, however, that it was a foot inside a shoe that revealed the occurrence of a death. Bodies left in the water over time naturally break down and it is common for the feet to loosen as the soft tissues of the feet and ankles deteriorate. Most modern shoes are buoyant, so they will float when released. This phenomenon has been found to be responsible for the discovery of 21 human feet (opens in a new tab) that have been stranded since 2007 in the Pacific Northwest.

Originally posted on Live Science.