Ancient methane bubbling up through permafrost cracks. Radiocarbon dating shows some gas has been trapped underground for 50,000 years.
The third pole is breathing
Across the vast, high-altitude landscape of the Qinghai-Tibetan Plateau, the ground is leaking ancient gas. This region, often called the "Third Pole" for its massive stores of ice and permafrost, is home to numerous methane seeps. In areas of alpine wetland and near thermokarst lakes—bodies of water formed by melting ground ice—the water appears to boil as bubbles of colorless and odorless methane (CH4) stream to the surface. This is not volcanic activity, but a cold, slow release of gas from deep within the Earth.
The seeps are a direct consequence of the plateau's unique geology. Much of the region is underlain by a deep layer of permafrost, soil and rock that has remained frozen for millennia. This frozen stratum is an impermeable cap, trapping gases from various sources beneath it. In some areas of the plateau, the permafrost can reach depths of over 80 meters. As the climate warms, this frozen seal weakens and fractures, allowing the trapped methane to find pathways to the atmosphere. The plateau has been warming at a rate of 0.3 to 0.5°C per decade, accelerating this process.
A message from the Pleistocene
The methane escaping from these seeps is exceptionally old. The hook for this location comes from the radiocarbon dating of the carbon atoms within the methane gas, which indicates it has been trapped underground for as long as 50,000 years. This means the gas was generated during the Pleistocene epoch, long before the last glacial maximum.
Scientific analysis of the gas's isotopic composition helps to identify its origin. The ratio of carbon-13 to carbon-12 isotopes can distinguish between biogenic methane, produced by microbes near the surface, and thermogenic methane, formed by geological heat acting on organic matter deep underground. Studies on the plateau show that while much of the methane from thermokarst lakes comes from the recent decomposition of young organic matter, some seeps release this much older, thermogenic gas. This ancient methane likely originates from deep coal seams or natural gas reservoirs sealed beneath the permafrost layer.
The release of this ancient methane is crucial to climate science. Methane is a potent greenhouse gas, and its release from thawing permafrost creates a positive feedback loop: warming releases methane, which in turn contributes to more warming. Researchers are actively measuring the flux from these seeps, with some thermokarst lakes on the plateau emitting methane at an average rate of 13.4 millimoles per square meter per day during the ice-free period.
💡Fun Facts
Radiocarbon dating confirms the carbon in the methane is up to 50,000 years old, originating from the Pleistocene.
The Tibetan Plateau's permafrost region covers an area of approximately 1.15 million square kilometers.
Methane bubbling, or ebullition, accounts for about 84% of the total methane released from the region's thermokarst lakes.
Some research suggests that the total number of thermokarst lakes on the plateau has nearly doubled since the 1980s, increasing from around 60,000 to over 120,000 by 2020.
This is a remote, high-altitude scientific research area above 4,000 meters. There are no tourist facilities, roads, or trails. Access is generally restricted to scientific expeditions with specialized off-road vehicles.