Image copyright Charles A. Wehner
A blaze in the Rocky Mountains in the US was lit by a person cooking the foods for a winter solstice celebration.
The fire was apparently started in 1860 and is the oldest well-documented fire in the Northern Hemisphere, fire experts say.
The fire was confirmed by a University of Oregon fire investigation group.
The fire burns for many hours before it appears to give off charcoal particles on the cold winds of winter.
The Solstice fire occurred around Christmas every year when the sun set just in time to trigger an onrush of hydrocarbons that sparked the blaze.
It lasted for a few weeks and this winter solstice milestone was when the flames were apparently extinguished.
The incident was depicted on a map by one of the early fire researchers, Charles A. Wehner.
Harmony, but no survival
The burning lasted for several hours. There were no consequences to the area, but the resulting warm charcoal smoke is known to have killed birds, insects and plants at the site.
“The formative environment of the Solstice fire has survived for tens of thousands of years,” said University of Oregon Earth scientist Rick Quesnel, one of the researchers in the study.
He added: “It’s a great example of how a fire started in a sequence of clearly identifiable events can have global effects.”
The team writes that this means climate “features and responses” involving a complex web of natural processes in the region may have influenced each other over time.
These could influence global climate patterns, the researchers said.
The Solstice fire stands out as the longest winter solstice blaze in the Northern Hemisphere, and a larger one than the oldest known wildfire in Antarctica – a 450,000-year-old fire dubbed the “Jagged Thunder” fire.
Image copyright UO Earth.
This fire occurred at the northern tip of the Chilean Antarctic plateau. It emerged out of the the Sedimentary Basin, a 40,000-year-old layer that was found 2km underground.
Share Fire at the site Image caption A map shows the timing of the Solstice fire for winter solstice