Beneath our feet, in sunless depths once thought barren, a vast and vibrant ecosystem thrives.

A groundbreaking study by Chinese and Canadian scientists has revealed the surprising “energy engine” powering this hidden biosphere: the very breaking and grinding of Earth’s crust during earthquakes and tectonic shifts.

Forget 19th century French novelist Jules Verne’s fantastical depictions of mastodons and giant dragonflies dwelling in mushroom forests nine to 12 metres (30 to 40 feet) tall in an illuminated subterranean world. Traditional science held that kilometres below the surface, cut off from sunlight and surface organics, life could not exist.

Yet, recent discoveries have unveiled a massive, active deep biosphere, harbouring an estimated 95 per cent of Earth’s prokaryotes and constituting roughly one-fifth of Earth’s total biomass.

But how do these microbes survive in the deepest, most isolated zones?

A study led by Zhu Jianxi and He Hongping, professors at the Guangzhou Institute of Geochemistry (GIG) under the Chinese Academy of Sciences, and Kurt Konhauser, professor at the University of Alberta, provides an answer.

Their findings were published in Science Advances on July 19.

They discovered that seismic activity and crustal fracturing act like a natural “generator”, constantly producing energy for deep life.

“In the silent darkness, chemical reactions between rock and water generate energy. This process functions like a battery, creating positive and negative poles that drive electron flow – the currency of life’s metabolism,” Zhu said in a GIG news release on July 19.

The team simulated Earth’s most common silicate mineral, quartz, in the lab to recreate two fundamental types of rock fracture: extension, where rocks suddenly crack open, exposing fresh surfaces instantly to water; and shear fracture, where faults grind continuously, crushing rocks in water.

Both fracture types split water molecules, producing hydrogen gas and reactive oxygen species. Extensions were particularly efficient at accumulating hydrogen peroxide.

The hydrogen peroxide paired with the generated hydrogen to form a natural “redox couple” – a pair of chemicals that drive reduction-oxidation reactions. This reaction produced electrical energy of up to 0.82 volts, easily sufficient to power most life-sustaining reactions.

Iron, one of Earth’s most abundant elements, acts as a crucial energy shuttle. Tiny amounts of hydrogen peroxide oxidise dissolved ferrous iron into ferric iron. Simultaneously, abundant reactive hydrogen atoms, produced during rock fracturing, reduce ferric iron minerals back to ferrous iron.

This continuous electron flow creates an “underground power grid”, energising microbial life and driving the biogeochemical cycles of carbon, nitrogen and sulphur.

As highlighted in the GIG report, the team discovered in 2023 that minerals under stress can produce oxygen at their surfaces, potentially exceeding production rates from atmospheric photochemistry.

“This long-overlooked radical chemistry could simultaneously explain the origins of Earth’s initial oxygen and hydrogen,” Zhu explained. “It might be the intrinsic mechanism driving the early co-evolution of minerals and life.”

“Furthermore, the deep subsurface provides a sanctuary, shielded from catastrophic events like intense ultraviolet radiation and asteroid impacts, offering a previously unrecognised crucial environment for the origin and evolution of life,” he added.

The study quantifies the power: a single moderate earthquake can generate hydrogen fluxes 100,000 times greater than production via radiolysis, which involves splitting water molecules through ionising radiation, or serpentinisation – a chemical reaction between water and ultramafic rocks at high temperatures and pressures.

Such intense energy flow can readily sustain populations of deep chemosynthetic microbes and may even lead to localised accumulations of dihydrogen gas.

According to He, “This process of converting mechanical energy into chemical energy isn’t unique to Earth.

“It applies to other planetary bodies like Mars … and Enceladus (a moon of the planet Saturn). Detecting signals related to redox couples – such as hydrogen, methane, oxygen, or redox fluctuations of iron – within Martian fault zones could indicate active subsurface life.”

So the next time you feel an earthquake’s tremor, remember: deep beneath the surface, in unfathomable darkness, shattering rocks might just be igniting sparks of life. The hidden worlds within Earth – and perhaps even Mars – could be far more alive than we ever imagined.

In the quest to harness the power of the stars, one of the greatest challenges lies not in mastering fusion, but in finding materials strong enough to contain it.

At the heart of a nuclear fusion reactor is an ultra-powerful superconducting magnet, operating at temperatures near absolute zero and under immense magnetic stress. For decades, scientists from around the world have struggled to find materials that simultaneously endure such extreme cold and extreme force.

Chinese scientists have detailed how they created CHSN01 (China high-strength low-temperature steel No 1), deployed it this year in the construction of world’s first fusion nuclear power generation reactor and put China in a leading position in materials science.

It was a decade-long journey marked by setbacks, doubt and ultimate triumph.

In 2011, the International Thermonuclear Experimental Reactor (ITER), which is under construction in southern France, faced a critical material challenge. Testing revealed that the cryogenic steel prepared had become brittle and lost its ductility.

ITER, the world’s largest fusion experiment, was launched in 2006 from a collaboration between seven members, including China.

At the core of the fusion device, superconducting magnets are armoured with cryogenic steel, like a jacket engineered to endure ultra-low temperatures. This material must withstand both liquid helium’s −269 degrees Celsius (−516 Fahrenheit) cryogenic environment and the massive Lorentz forces generated by intense magnetic fields.

Global ITER teams investigated the cause and refined production protocols. In 2011, China’s team developed the first viable solution but Li Laifeng, a researcher at the Chinese Academy of Sciences’ (CAS) Technical Institute of Physics and Chemistry in Beijing, still had qualms.

In a China Science Daily article, Li wrote: “While ITER’s maximum 11.8 Tesla field design is enough for itself, future higher-field magnets will require advanced materials”. He added that ITER could not generate electricity, but China’s own reactor would.

The challenge in 2011 pushed China to spend more than a decade developing the proprietary cryogenic steel. Li’s team initially experimented with nitrogen-enhanced N50 stainless steel, which improved yield strength but failed to enhance cryogenic toughness.

In 2017, Li went to the United States to take part in the International Cryogenic Materials Conference, where he introduced his new material.

However, foreign experts were sceptical, believing the existing technological route was “absolutely impossible” to produce better cryogenic steel, according to the Science Daily report. They had considered the existing ITER conductor jackets which used 316LN austenitic stainless steel – a specialised alloy designed for extreme conditions – to be sufficient.

In 2017, subsequent trials, in which the Chinese team incorporated vanadium while controlling carbon/nitrogen ratios, achieved a better strength-toughness balance. But the new steel still did not perform at the level needed.

Progress stalled until 2020, when physicist Zhao Zhongxian joined the team’s meetings.

Zhao is a Chinese Academy of Sciences academician and a world-leading expert in cryogenic physics who won China’s top national science award in 2017 for his superconducting material research.

He had long emphasised the critical role of materials in superconducting technology applications across multiple fields, and actively asked to take part in Li’s team meetings.

“Do not blindly trust foreign authorities. This matter is worth pursuing.” he was quoted by the Science Daily report as saying to the researchers.

In 2021, the Institute of Plasma Physics, CAS, in Hefei province, established core engineering specifications for China’s fusion programme: 1,500-megapascal (MPa) yield strength and over 25 per cent elongation at cryogenic temperatures.

At the time, magnetic confinement fusion expert Li Jiangang described the stakes: “Developing next-gen cryogenic steel isn’t optional – it’s essential for the success of China’s compact fusion energy experimental devices”.

By late 2021, the High-Strength Steel Research Alliance was formed, uniting four institutes, 13 enterprises and four welding specialists under Li Laifeng’s leadership, sharing its technological advances with the industry and carrying a goal of developing a new type of domestic cryogenic steel.

Their biweekly technical forums and a “racehorse” development model – in which blind samples underwent independent evaluation at the Institute of Physics and Chemistry – accelerated progress.

In August 2023, experts confirmed that the new CHSN01 steel had met the engineering benchmarks that had been set. The material could withstand 20 Tesla magnetic fields and 1,300MPa stresses while showing superior fatigue resistance compared to traditional alloys.

It has since been deployed in a Chinese fusion reactor project, and the authors wrote about the 12-year process to develop the material in a paper published in Applied Sciences in May.

On May 1, China’s Best (Burning Plasma Experimental Superconducting Tokamak) entered its assembly phase, with an expected completion date in 2027.

Of the more than 6,000 tonnes of components assembled on-site, the straight segments of the superconducting conductor jackets comprise 500 tonnes. These core components are all made from domestically produced CHSN01 steel.

The country is looking to capitalise on the cryogenic steel development beyond the reactor.

“In addition to its applications in superconductivity, this steel can also be used in other related areas,” Zhao said.