The desolate landscape of the Arctic icecap is about to change, at least temporarily. First, one hears the noise, and then something rises out of the ice.
On the top of the world, 200 miles north of Alaska, it's a nuclear powered attack submarine, the USS Annapolis, crashing through three feet of ice. This is a military exercise in an area that may hold a quarter of the world's undiscovered oil. It's a mission that has now become critical because of climate change.
For the first time, the Navy has allowed a network television crew to see its ICEX exercises, which it conducts every two years. The purpose is to prove the Navy can operate in this unforgiving environment to protect the national interests.
Those interests could be threatened because the Arctic ice is thinning and receding more every year, possibly allowing more access to this now frozen body of water.
A new National Science Foundation report suggests that the melt is so quick that the Arctic could be devoid of ice in the summertime by 2040. That could start a "gold rush" of sorts for all that "black gold" under the Arctic's seabed.
"One expects to see more military exercises here, but [one] could, you know, eventually, if our fears come to roost, even [see] commercial transportation here," U.S. Energy Secretary Steven Chu told ABC News moments after he stepped onto the ice from the Annapolis.
"This is a very difficult environment for the submarines to operate in," said Navy Capt. Gregory Ott, standing in a plywood hut that served as his headquarters for the exercises on the ice.
A crew of 50 scientists and sailors lived for a month in the temporary "ice camp" to work with the subs.
"The ocean here is almost the upside down of oceans elsewhere. Here, it's actually colder near the surface where most oceans are warmer near the surface," Ott said.
That temperature difference affects buoyancy, only one of the challenges the submarines face in the extreme Arctic.
So, when the commander of a nearly $1 billion submarine ordered his crew to surface, nothing was routine.
"It was the most nervous I've been in my career," said Cmdr. Michael Brunner in a chat 350 feet below the surface of the ice in the Annapolis' control room. "I don't get less nervous with each one. We've done five vertical surfacings and [with] each one, the Arctic environment throws a little curveball at us."
Brunner's sub had just been retrofitted with the latest sonar and communication gear. But all the technology in the world doesn't guarantee an accident-free surfacing.
During its time in the Arctic, the Annapolis tried out its new communication system. (It sounds a bit like an old dial-up modem.) The crew sent messages to the surface and to the USS Helena, another sub in the area for the exercises. And the crew practiced firing torpedoes.
"Weapon in motion," one of the torpedo room crew members shouted as a massive weapon was loaded into a tube.
Up in the control room, the commander ordered his crew to fire on a fictitious target.
"Shoot tube 4. Fire tube 4. Torpedo course 0-5-1," were the rapid-fire orders in the control room.
The salinity of the water under the ice is much different than open water; torpedoes "swim" differently there. The test firing was repeated often. But those were expensive weapons even if they weren't armed.