A Russian flag was planted on the North Pole seabed Thursday as man reached the bottom of the top of the world for the first time in an expedition likely to accelerate the scramble for rich underwater deposits.

Two mini-submarines, Mir-1 and Mir-2, carried three-man crews more than four kilometers below the Arctic surface and back up again in a nine-hour operation. A mechanical arm dropped the rust proof flag on the seabed from Mir-1 as part of Russia’s attempts to bolster its claim for a vast part of the Arctic floor.

“It was a soft landing,” Alexander Begak, the expedition’s press attache, said by telephone from on board the research vessel Akademik Fyodorov, which along with the nuclear icebreaker Rossia made up the expedition.

On board the submarines were polar explorer Artur Chilingarov, who is deputy speaker in the State Duma and President Vladimir Putin’s envoy to the Arctic, Duma Deputy Vladimir Gruzdev and Anatoly Sagalevich, chief of the Oceanology Institute of the Russian Academy of Sciences.

“The landing was smooth, the yellowish ground is around us and no sea dwellers are visible,” Chilingarov was quoted as saying from the bottom by Itar-Tass.

The second submarine was manned by Swedish businessman Frederik Paulsen and Australian adventurer Mike McDowell. NTV television reported Wednesday that McDowell paid $3 million to go on the privately funded expedition.

The crew took samples from the seabed as part of an attempt to claim a large chunk of the Arctic. Russia maintains that the Lomonosov Ridge, an underwater shelf that runs through the Arctic, is part of Russia’s offshore territory.

“The aim of the expedition is to prove that our shelf extends to the North Pole,” Foreign Minister Sergei Lavrov was quoted as saying by Interfax. Lavrov added that Russia’s claims would be pursued through international legal channels.

Other countries with Arctic territory were quick to dismiss the act.

“This isn’t the 15th century. You can’t go around the world and just plant flags and say ‘We’re claiming this territory,'” Canadian Foreign Minister Peter MacKay was quoted as saying in televised remarks by Reuters. “There is no threat to Canadian sovereignty in the Arctic … we’re not at all concerned about this mission — basically it’s just a show by Russia.”

“I think in a few days U.S. explorers will be in the area,” said Hali Ullen, of the Institute of Oceanology, which provided the two submarines.

Chilingarov said the United States was keeping a careful eye on events and that UN and NATO planes were also spotted watching the expedition.

The two submarines descended from a 25-meter-by-10-meter opening in the ice early Thursday morning. The first vessel was piloted by Sagalevich, who manned the submarine that took the footage of the wreck of the Titanic used in the Hollywood film by the same name.

“The most difficult part of the operation was surfacing,” said Begak.

The submarines, which are only 8 meters long, had to make sure they found the opening, and not the 1 1/2-meter-thick ice. Begak said it was “like hitting a hole the size of the eye of a needle.”

Mir-1 appeared above the water eight hours and 40 minutes after submerging, spending 40 minutes below the ice before it found open sea, Begak said. Mir-2 surfaced an hour later.

Currently no country has exclusive jurisdiction over the Arctic. Canada, Denmark, Norway, Russia and the United States each control a 320-kilometer economic zone beyond their shores.

Moscow first tried to claim the Arctic territory in 2001, but that claim was rejected. It has been gathering evidence since then in preparation for its next opportunity to submit the claim to a UN commission in 2009. To claim the area, Russia must prove that the area in question is linked to its territory as part of the same continental shelf.

The economic interests involved are immense, as the Arctic region could hold up to one-quarter of the planet’s remaining untapped oil and gas reserves, according to some estimates.

“This expedition is symbolic of a new era in the exploration and extraction of oil in the Arctic Ocean,” said Vladimir Chuprov, the head of the energy unit for Greenpeace Russia. “Its a scientific and a geopolitical expedition.”

Chuprov said drilling for oil in the Arctic would only mean increased greenhouse gas emissions and the destruction of one of the cleanest areas left on the planet.

“It goes against the activities and aims of mankind to cut greenhouse gas emissions by 2050,” he said, referring to the target agreed upon at the Group of Eight summit in Germany in June.

The Institute of Oceanology’s Ullen insisted that it was too early to be concerned about the threat to the Arctic’s environment.

“It is a question for 30 to 40 years from now,” Ullen said. “Scientific research should be done.

“This expedition shows the ability of Russian technology and Russian science,” he said, adding that the Arctic’s future had to be decided through multilateral negotiations. “A united effort to explore the area is the best approach.”

At home, the expedition has been spun to appeal to patriotic Russians who remember Soviet displays of derring-do. Russia has a long history of polar exploration, having created the first floating polar research station in 1937.

“Our aim is to remind the whole world that Russia is a great polar- and scientific-research power,” Chilingarov was quoted as saying by Interfax.

Chilingarov previously compared the feat to space exploration. “To stand on one’s feet at such a depth — it is like the first step on the moon,” he said.

To underline the comparison, the submarine crew spoke with the Russian crew of the international space station via a telephone linkup, Begak said. “They asked each other a few questions,” he said, and then the connection was broken.

Channel One television noted that the crew did not wear shoes before they got into the submarine, just like cosmonauts.