A fire in a national park in Australia has been burning for at least 6,000 years.
The oldest fire on the planet is known as 'Burning Mountain'. Some scientists think it may be more ancient than we think.
Located under Mount Wingen in the state of New South Wales, this underground smolder is a coal seam fire, one of thousands burning at any one time around the globe.
These fires are hard to put out. They travel through the coal seam, a layer of coal that naturally occurs beneath Earth's surface.
"No one knows the size of the fire under Burning Mountain, you can only infer it," says a professor of fire science at Imperial College London.
He says it's likely a ball of around 5 to 10 meters in diameter.
He visited Burning Mountain on his field trip bucket list.
The man was at Mount Wingen. All rights go to Guillermo Rein.
Unlike a typical fire, a coal seam fire burns underground, which means there's no flame and it's more like ashes in a barbecue, rather than a coal fire. It's not to be confused with coal seam gas fires, which can cause waterways to catch fire.
The fire at Mount Wingen is burning underground and moving south at a speed of around 1 meter per year.
If you go to the national park, you'll see smoke and white ash, ground that's warm to the touch, discolored rocks of yellow and red, and a sulfuric smell as the fire below cooks the minerals of the mountain.
The public domain of Beruthiel/Wikimedia.
The path the fire has taken is visible even though it's mostly invisible, with more recently burnt areas covered in ash and devoid of plant life.
You can see the beautiful forest ahead of the fire. There's nothing left of the fire, not even grass. The forest has come back, but it's a different forest than it was 20 to 30 years ago.
There is a sign at a national park. All rights go to Guillermo Rein.
The Silent Hill fire, which has been burning for almost 60 years, is one of the many coal seam fires caused by human interference.
It's a blink of an eye compared to the thousands of years of Burning Mountain.
No one is sure what started it.
The first documented European volcano was discovered in the Mount Wingen region in 1828.
The alleged volcano was found to be a coal seam fire by Reverend CPN Wilton a year later. The path of the fire is thought to have been alight for at least 6,000 years. There has been no official research done on the area.
The Wanaruah people used the site for cooking and crafting weapons. Their origin stories talk about a widow whose tears lit the fire or the torch of a warrior captured by the 'Evil One' under the mountain.
Natural causes are the most likely source.
He says that it was most likely natural causes. It could have been caused by a lighting strike. It could have been self-heating.
When the coal seam is close to the surface, it can be exposed to oxygen. If there are enough sunny and hot days in a row, the surface of the coal will get hot enough to heat up the next piece in the seam, which in turn will cause ignition.
The self-heating point for coal can range from 35 to 140 degrees Celsius.
We don't know how old the fire is. The same fire could have been burning for a long time.
It's at least 6,000 years old. It could be hundreds of thousands of years old.
This evidence is not peer-reviewed so needs to be taken with a grain of salt. It only adds to the mystery of this fire.
The painting of Mount Wingen was done by Emma Macpherson. The public domain/Wikimedia Commons.
Under its own steam.
How long will Mount Wingen burn? We don't know how far the coal seam stretches or where it goes next. There is no shortage of oxygen supply.
It could burn for thousands of years without intervention.
"As the fire progresses, it heats up the mountain causing it to expand and crack, letting in oxygen so the fire can move forward."
Coal seam fires require tons of water and liquid nitrogen, which is hard to put out with human intervention. In 2004, China claimed to have extinguished a fire that had been burning for 50 years, only to have visitors see it burning again a few years later.
During his visit to Burning Mountain in 2014, he noted that the smolder was approaching a cliff. We could see some dramatic changes to Burning Mountain within the next decades if the coal seam does well.
"If the coal seam breaks through the cliff, it could cause flames with much more heat," says Rein. He thinks that this may be similar to when the fire was mistaken for a volcano in 1828.
If the coal seam goes very deep, it will smolder out and extinguish itself, which would be very dramatic if that happened during our lifetime after burning for hundreds of thousands of years.
While Mount Wingen is far away from civilization to cause harm, larger coal fires can be a serious health and safety hazard that have become more common in recent years.
They could be contributing to the plight of our planet by becoming more common due to climate change. Coal fire greenhouse gases release large amounts of CO2, methane, and other pollutants, but little is known about the impact on the environment.
The impact of climate change on coal seam fires is something we should be very concerned about, according to Rein.
It's frustrating that no one is benefiting from the fires, it's a huge potential source of heat and energy that's going undiscovered.
It's comforting to know that mysteries such as Burning Mountain still exist, even though further research is needed into coal seam fires as our planet heats up.
