The Arctic: the smallest of Earth’s five oceans, with icy waters and dagger-like winds, is home to some of the most unforgiving conditions on the planet.

But far below the skin of sea ice that waxes and wanes with the seasons, this inhospitable ocean is hiding a treasure trove of natural resources – one that’s largely untapped by mankind.

The Arctic Ocean is estimated to hold billions of barrels of oil, and trillions of cubic feet of natural gas – accounting for 16-26% of the Earth’s undiscovered reserves. And there’s a superpower scrambling to beat all others in the race to exploit this chilly mother lode of polar resources: Russia.

Decades after the Soviet Union fell, Russia embarked on a mission to drill deep into the Arctic seabed, sending a fleet of underwater robots and unmanned submarines into the Earth’s harshest waters.

And now, after years of drilling in the area, the country – which saw oil and natural gas account for 68% of its exports in 2013 – plans to use never-before-seen technology to take its mission to the next level.

Russia already extracts around 5.5 million tons of oil annually from its only operating oil field in the Arctic, but much of the sea is covered by a thick sheet of ice year-round, making exploitation by surface vessels impossible. Enter Russia’s Project Iceberg: an ambitious plan to use extreme technology for equally extreme conditions. We talked to experts who shone a light on Russia’s designs on the Arctic.

***

The race for the Arctic’s precious resources isn’t new. The hoard of gas and oil is surrounded by powerful nations – Russia, Denmark, Norway, the US and Canada – and they all want a piece of the pie.

Russia itself has been drilling in the Arctic Circle for decades. In August 2007, it made a dangerous and globally provocative move by sending two Russian mini-submarines 4,200m (14,000ft) below the North Pole to plant a rust-proof titanium flag on the seabed to stake a claim on the territory.

Project Iceberg could be the nation’s power play to make sure it keeps a regional monopoly on those two resources

Now, in 2017, the global community is keeping a close eye on Russia as it seeks to expand its grip and influence on Arctic waters – and the valuable resources within. For Russia, oil and natural gas are key sources of both energy and income. Project Iceberg could be the nation’s power play to make sure it keeps a regional monopoly on those two resources.

Russia is already expanding its military might in the Arctic, building more bases in the area after opening several earlier this year. In April, BBC journalists were the first foreign journalists allowed to film Russia’s military brigade stationed in the Arctic, close to the Finnish border. The increased military presence in the region is a sign of Russia’s growing Arctic ambitions at a time when receding ice is making the energy resources it holds more accessible than ever.

In much the same way as extracting oil from the North Sea was considered to be an engineering challenge in the 1970s as nobody had operated drilling platforms so far north in such difficult weather conditions before, the Arctic poses similar barriers today. With water up to 5km (3.1 miles) deep in places and largely covered with ice, the Arctic is arguably the hardest place in the world to drill for oil.

But then, nobody has attempted anything like Project Iceberg before.

The Foundation for Advanced Studies, the Russian equivalent of America’s Darpa, states it is planning “fully autonomous underwater, under-ice, development of hydrocarbon fields in the Arctic seas with severe ice conditions”. In other words: oil-seeking robotic submarines.

But there are some who suggest Iceberg’s stated goals are unrealistic – and that they may be a smokescreen for the development of military systems that can be deployed under the ice.

What is almost certain is that the project will add muscle to Russia’s vast territorial claims in the Arctic, which are currently under consideration by the UN.

***

The centrepiece of Iceberg is the 182m-long (600 ft) Belgorod, the largest nuclear submarine ever built. The Belgorod will carry out underwater surveys and lay communication cables under the ice, but its main role will be to act as a mothership for a flotilla of smaller submarines.

“The Belgorod submarine is a platform for deployment of various systems, including ones that do not yet exist,” says Vadim Kozyulin, a defence analyst at PIR Centre, a thinktank focusing on security issues.

This is the reason for the sub’s enormous size: a new 30m (100 ft) section has been added with docking facilities for both manned and unmanned submarines.

Perhaps the most ambitious part of Project Iceberg are the plans for the word’s first underwater nuclear power plants to act as pitstops for the swarms of submarines

But perhaps the most ambitious part of Project Iceberg are the plans for the word’s first underwater nuclear power plants to act as pitstops for the swarms of submarines that will be deployed.

These underwater power stations will sit on the sea bed and act as recharging points for passing unmanned subs. The current design is for a 24-megawatt reactor with a lifetime of 25 years. Each one will operate almost entirely autonomously with technicians only visiting once a year for routine maintenance.

But Russia has a poor record on nuclear safety at sea, having lost seven nuclear submarines since 1961, some of them because of reactor problems. Accidents on board vessels operated by the former Soviet Union account for 14 of the most deadly nuclear incidents to have occurred at sea. In one case the entire sub was exposed to high radiation levels, while another suffered a loss of coolant and a partial reactor meltdown. One such accident was dramatised in the Hollywood movie K-19: The Widowmaker.

Russian power company Nikiet actually suggests that having no human operators will improve safety. No humans means less risk of human errors like the one which lead to the Chernobyl disaster, where operators overrode the safety systems that would have shut the reactor down.

“My sense is that much of the nuclear technology proposed here is mature and well understood,” says William Nuttall, professor of energy at The Open University in the UK.

Eugene Shwageraus of Cambridge University’s Nuclear Energy Centre says that while the reactor might be unmanned, it could still be supervised, and in that sense it would be similar to many modern reactors which require little operator engagement day-to-day.

“Today’s reactors are already quite ‘autonomous’, producing power 24/7 with reactor operators just observing the plant diagnostic instruments’ readings,” says Shwageraus.

The underwater reactors are said to be at an advanced stage of development, with the aim of having the first one operational by 2020

The underwater reactors are said to be at an advanced stage of development, with the aim of having the first one operational by 2020. And while there will be some humans involved in this aspect of Project Iceberg, many other routine operations will be carried out by robots alone.

The workhorses will be deepwater unmanned submarines or autonomous underwater vehicles (AUVs). AUVs are currently used in small numbers by many nations, and generally under close operator control rather than roving freely. Russia has previously lagged in this area, but they seem to be catching up.

The Harpsichord-2R-PM AUV has been developed for Iceberg, and is intended to be the forerunner of a whole family of different underwater vehicles. This two-tonne, 6m-long (20ft) torpedo-like craft is currently being tested in the Black Sea but has also being used to help in the recovery of crashed aircraft. In 2009, one of these AUV’s located a Russian Navy plane, which had crashed killing all 11 people on board during a training flight. The plane had come down in the sea off Sakhalin, a Russian island near Japan, but the search on the surface was hampered by ice and severe weather. The AUV’s ability to operate by itself beneath the waves allowed it to successfully recover the black box flight recorders needed to help determine the cause of the crash.

While AUVs are often already used for underwater surveying, there is no precedent for using them to drill on the sea bed. Igor Vilnit, head of Russia’s largest submarine design company the Rubin Central Design Bureau for Marine Engineering, claims they are on course to have a working AUV drill in action in as little as five years.

Amid all this drilling and underwater exploration, though, there are bigger changes afoot that extend beyond even the simmering political tensions. Climate change is hastening the melting of the Arctic’s ice caps – this presents a slew of challenges for the indigenous peoples who call the region home, as well as for wildlife, like polar bears.

But as rising temperatures melt the Arctic ice cap, leaving the region more hospitable and accessible, climate change is also likely to exacerbate the political turmoil in the area too.

***

At a conference in March, Russian Deputy Prime Minister Dmitry Rogozin said development of the Arctic region would help to build neighbourly relations with surrounding states and that it should be a "territory of peace and cooperation".  But this is hardly consistent with other Russian activity in the area.

Some 50 former Soviet Arctic military bases have recently been reactivated. The Russian army has new Arctic Brigades, and showed off special military vehicles for polar operations in this year’s May Day parade. Russia‘s Northern Fleet is also to get its own advanced icebreaker, as well as “ice capable” patrol vessels, essentially mini-icebreakers armed with anti-ship missiles.

Project Iceberg is also going ahead in the face of sanctions imposed by Western countries against Russia in the wake of its annexation of Crimea. The sanctions restricted the access that Russia’s oil and gas companies had to the sort of foreign finance and technology needed to develop wells in the difficult Arctic environment. Instead Russia has chosen to go it alone. Earlier this year the country began a complex horizontal drilling operation from a remote peninsula on the edge of the Laptev Sea to reach oil reserves up to 15km (9.3 miles) under the frozen ocean.

The underwater water reactors might, for example be used to power Russia’s planned sonar fence, known as Harmony, which detects and tracks Nato submarines

But Kozyulin is dubious about the chain of underwater nuclear recharging stations that are planned under Project Iceberg, calling them “too fantastic”. He asks why, if this is supposedly a commercial drilling operation, are Gazprom or one of Russia’s other oil companies not involved? Kozyulin finds it easier to believe Iceberg’s true purpose is a military one. The underwater water reactors might, for example, be used to power Russia’s planned sonar fence, known as Harmony, which detects and tracks Nato submarines.

Russia is pursuing claims for an expanded underwater territory in the Arctic with the UN's Commission on the Limits of the Continental Shelf. These claims conflict with those of other nations including Canada, says Stephen Blank, a Russia expert at the American Foreign Policy Council. Russia has had some success with UN claims in the past.

“The Commission gave Russia the right to extensive holdings in the Sea of Okhotsk (in the Western Pacific) in 2013,” says Blank. “Moscow promptly converted it into an exclusive naval bastion and preserve for its energy companies.  That would likely serve as a precedent regarding the Arctic.”

Blank believes the Russian military build-up is due to fears that other nations might try to seize the energy resources in the Arctic first.

“It would not surprise me if they have also had a secret deep-water deployment of some sort for some time,” says Blank.

It is hard to tell if the Iceberg plan to exploit Arctic gas and oil is realistic, or whether Russia simply wants to secure the territory so that it can exploit it at some time in the future.

What nobody should doubt is Russia’s determination that if anyone is to profit from the Arctic, it will be them.

--

Join 800,000+ Future fans by liking us on Facebook, or follow us on Twitter.

If you liked this story, sign up for the weekly bbc.com features newsletter, called “If You Only Read 6 Things This Week”. A handpicked selection of stories from BBC Future, Earth, Culture, Capital, and Travel, delivered to your inbox every Friday.