The secret of a fire that has been burning in Australia for at least 6,000 years
In a national park in northern Sydney, Australia, a fire is burning spontaneously and out of control and has been burning for at least 6,000 years. Known as the Burning Mountain (Wingen Hill), this mysterious underground fire is the oldest known fire on Earth. Some scientists estimate that fire may be even older than we think. Located under Mount Wingen, New South Wales, this underground fire is a type of coal fire that is one of thousands of examples of such fires that exist at any time around the world.
Once ignited, it is almost impossible to extinguish these underground fires. They walk slowly but steadily on the coal vein, which is a layer of coal that is naturally below the surface of the earth. “No one knows the size of the fire under the burning mountain, and only the size can be deduced,” Guillermo Rein, a professor of fire science at the Royal College of Physicians in London, told ScienceElert. “The ball is probably 5 to 10 meters in diameter, with a temperature of a thousand degrees Celsius.” Rain visited Mount Susan in 2014.
Unlike ordinary fire, a fire that is created in a vein of underground coal has no flame and burns like light coal. At present, the fire on Mount Wingen burns about 30 meters underground and is moving south at a speed of one meter per year.
The only signs of a burning mountain fire are some smoke, white ash, warm earth, yellow and red stones, and the smell of sulfur that emits when the basement fire heats the minerals.
Although fire is now largely invisible, its path can be traced more closely. Areas that have recently been burned are covered in ash and devoid of vegetation. Rin says:
Before the fire arrives, you see this beautiful eucalyptus forest; But where there is fire now, there is no life and not even grass. In a place where there was a fire 20 to 30 years ago, the forest is back; But it is different from before. Fire has changed the landscape.
A sign in the burning mountain national park
Many coal fires, especially those in India, China, and the United States, are the result of human intervention such as coal mining. One example is the infamous fire under Central Australia in Pennsylvania. Centralia is an abandoned city inspired by the film Silent Hill. This fire has been burning for almost 60 years; But this time is very short compared to the thousands of years that the burning mountain has been burning.
Who started the burning mountain in Australia?
No one knows for sure how the fire was first ignited. The first European documentary observation was made in 1828; That is, when local agriculture announced that it had discovered a volcano in the Wingen Mountain area. A year later, geologist Charles Wilton concluded that the volcano was in fact a coal fire. Since then, measurements have shown that the path of the fire is about 5.6 kilometers long and, accordingly, has been lit for at least 6,000 years; Apart from this example, however, formal research has rarely been conducted in the area.
The burning mountain was considered by the traditional guardians as a sacred place in the valley; That is, the same Vanarwa people who used it for cooking and making weapons. The stories of its origin tell of a widow whose tears ignite the fire or torch of a warrior captured by the devil under a mountain.
According to Rin, the fire is probably of natural origin. He explains:
You can not rule out human intervention; But it most likely had natural causes. The fire may have been caused by lightning, which ignited the bare minerals, or it may have been ignited by its own heat.
This type of ignition occurs when the coal vein is close enough to the surface and exposed to oxygen. If there are enough sunny and hot days in a row (something we will see with more climate change), the surface of the coal heats up enough to heat the next piece of vein and eventually ignite. Studies show that the temperature at which coal can ignite spontaneously varies from 35 to 140 degrees Celsius.
More interestingly, we do not know exactly how old the burning mountain in Australia is. Researchers have found evidence that the fire may have been burning for much longer. “It’s not necessarily 6,000 years old,” says Rain. It is at least 6,000 years old. “In fact, it could be hundreds of thousands of years old.”
The evidence has not been published in a reputable journal or reviewed by experts; Therefore, they should be viewed with skepticism. However, this only adds to the mystery of this well-studied fire.
Wingen Mountain Painting by Emma McPherson, 1915-1833
How long does Mount Wingen burn?
Nobody knows. We do not know how far the coal vein extends or where it will go later. There is currently no shortage of oxygen. Rin says:
This fire can burn for thousands of years without human intervention. As the fire progresses, the mountain heats up and cracks. In this way, oxygen enters and the fire can move forward. Chimney fire produces its own oxygen.
Even with human intervention, it is very difficult to put out coal fires and requires a lot of liquid water and nitrogen. China claimed in 2004 that it had extinguished a fire that had been burning for 50 years; But a few years later, visitors saw signs of it burning.
During Rain’s 2014 visit to the area, the smoke from the burning mountain was approaching a cliff at the bottom of a small river. Depending on what the coal vein in the river does, we can see dramatic changes in the burning mountains in the coming decades. “A vein of coal may pass through and become apparent near the surface of the rock,” says Rain. “It can lead to much hotter flames.” According to his prediction, this situation may be similar to what happened in 1828 when fire was confused with a volcano. “If the coal vein is too deep, it suffocates and burns without a flame, producing smoke,” adds Rin.
Importantly, while Mount Wingen is far enough away from civilization that it does not cause harm, larger coal fires can pose serious safety and health hazards that have become very common in recent years. Not only can they become more common due to climate change; They can also make the planet worse off.
Few studies have been conducted on the impact of greenhouse gases from coal fires; But they have been shown to release large amounts of carbon dioxide and methane, as well as other pollutants such as mercury. Rin says:
The impact of climate change on coal vein fires and the impact of these fires on climate change is something we should be very concerned about. The frustrating thing is that no one uses these fires. These are great sources of heat and energy that are not being used.
While more research is needed on coal fires on a warming planet, it is a little encouraging to know that on a sunken planet, there are still phenomena such as burning mountains that are unknown and have not been well studied.