This summer, scientists mapped more than 20,000 square miles in the Gulf of Mexico. The red lines indicate newly mapped areas of the continental shelf. *

Illustration: Chuck Carter/Paul Morin * Two and a half miles below the bright, icy surface of the North Pole, in the dark calm of the deep, a robotic arm extending from a submarine jammed a 3-foot Russian flag into the ocean floor. The audacious move, captured by underwater cameras mounted on the face of the sub, made headlines around the globe in August. Not since the scramble to the pole a century ago had there been such nationalistic bravado at the top of the world. With five countries — Russia, Canada, the US, Norway, and Denmark — looking north, Russia's claim was heralded as the beginning of what could become a mad scrum over trillions of dollars in untapped oil and natural gas in one of the last regions on earth where geopolitical lines have yet to be drawn.

Some 3,200 miles and 47 degrees of latitude away, at the University of New Hampshire's Center for Coastal and Ocean Mapping (CCOM), Jim Gardner followed the action with intense interest and a wry smile. One of the country's foremost marine geologists, Gardner knew the flag-planting itself was meaningless; it gave the Russians as much legal claim to the undersea Arctic as the US got to the moon when Armstrong and Aldrin put up the Stars and Stripes in the Sea of Tranquility. He also knew, however, that the Russians had a legitimate reason to celebrate. The stunt capped off a Russian study of vast swaths of uncharted seafloor, including the survey of an undersea mountain range called the Lomonosov Ridge. Canada and Denmark are also arguing that the ridge is their own, but Russia's new maps could prove it actually belongs to Moscow. And it's this kind of work — not the flag-planting — that is at the center of the current "landgrab" in the Arctic, and indeed across the globe.

For centuries, nations marked what they owned at sea by measuring out from their shoreline. But in 1994, the United Nations Convention on the Law of the Sea took effect. It stated that countries can move their boundary lines to the edge of their continental shelf — this can give them more territory but is difficult to determine. Today, as sea ice thaws and undersea mapping technology improves, countries are rushing to assert their ownership over potentially lucrative chunks of extra turf.

To assert sovereignty over its submerged continental shelf, a nation has to map multiple off-shore points. Among them: the area where the ocean depth drops to 2,500 meters, and the place where a country's land mass drops off to become seafloor, a spot called the foot of the continental slope. If these points are farther out than current boundaries, there may be a case for extending the oceanic property line. But the foot of the slope can be tricky to locate. Think of a continent as a big rock sitting in a bathtub, and imagine that a chunk of it rises out of the water. The question for scientists is, where does the rock end and the acrylic tub begin? It sounds simple enough, but imagine now that your tub is also made of rock, and that smaller rocks are piled up all over the place.

Because new territory could mean new natural resources, CCOM researchers, tapped by the US government and led by Gardner, have been silently scanning for six years now — mapping the frozen north as well as the Bering Sea, the gulfs of Alaska and Mexico, the Atlantic Margin off the East Coast, and the Marianas in the Pacific. They're racing to prove the US controls more territory than anyone thought. Alaska, for example, could extend 150 miles farther into the Arctic Ocean than today's maps show. And the country's sovereignty may not end off the shore of the Gulf Coast; it's really more like the middle of the Gulf of Mexico.

Of course, if everyone's territory extends an extra 150 miles, then a lot of countries are going to be planting their colors in the same ground. Britain, which claimed a certain chunk of Antarctica a century ago, has already gotten into a scuffle with Argentina and Chile about overlapping claims near the South Pole. The same thing will almost certainly happen in the Arctic, with a big battle brewing between Russia, Denmark, and Canada over the Lomonosov Ridge.

Conservative estimates suggest that a new set of boundaries could cause the US to "grow" by at least 386,000 square miles, and the oil, gas, and other resources contained in that area could be worth about $1.3 trillion. With so much money at stake, Gardner's job is to collect the data that will allow his country to extend its fence line as far as the science can justify.

Jim Gardner's maps could give the US access to a trillion dollars in untapped oil and natural gas.

Photo: Chris MuellerA bespectacled guy with a solid build and white beard that makes him look at home at sea, Gardner has been poking and plumbing and scanning the ocean floor since the 1960s. Twenty-five years ago, when the standard limit on territorial claims was 200 miles out from shore, he led the project to map the United States' undersea territory. Now, faced with the possibility that the country could outgrow those drawings, Gardner has put off retirement. He's commanding a 247-foot research ship that passes over places where the exact topography of the continental shelf is unknown, shooting down sound waves and then figuring out what the seafloor looks like by how the signals bounce back up. His boat crosses back and forth in a process he compares to "mowing a giant lawn."

Down in the ship's belly, Gardner monitors a bank of computer screens linked to a sonar system called a multibeam echosounder, which is affixed to the ship's hull in the shape of a cross. Forming the long part of the cross are sonar devices that repeatedly shoot bursts of sound into the water. Each blast lasts a mere 15 milliseconds, and as the sound waves bounce back, they're picked up by receiving sensors that make up the crosslike array's other line. Motion sensors link up with the computers and compensate for the roll of the ocean. "Even though the ship is flopping and these angles are shifting, the system is keeping the data stable by making adjustments hundreds of times every second," Gardner says. The boat's onboard GPS is also connected to Gardner's computers, syncing the soundings with the ship's location.

To calibrate the data, Gardner also fires disposable thermometers down into the water, making him look somewhat like a whaler harpooning minnows. The instrument, called an expendable bathythermograph, is little more than a shaped weight with a temperature sensor inside. As they sink, they spit numbers back to the surface, allowing Gardner to plot the temperature of the water at various depths — the colder the water, the slower his sound waves will travel — and adjust the information he gets from the echosounder. In the Arctic waters, there's an additional challenge created by the presence of ice: Listening to underwater sounds isn't easy when your sensors are distracted by the thud-thud of the ship plowing through chunks of ice the size of buses.

The looming threat of overlapping claims is creating tension in the Arctic, where the bounty is greatest and the boundaries are faintest. During one cruise near Siberia, researchers from the New Hampshire team were buzzed by a Russian reconnaissance plane that had been scrambled to the area to keep an eye on the US scientists. Last summer, during a military exercise dubbed Operation Nanook, Canada announced it would construct up to eight new naval ships to patrol the Arctic region and also build an army training center there.

Of course, in the annals of maritime property rights, militarist undertones are nothing new. A country's nautical reach was once governed by the so-called Cannon Shot Rule, a doctrine that gave countries control of waters up to 3 miles out — roughly the range of a cannon in the 17th century. Advances in artillery notwithstanding, the 3-mile rule held sway into the 20th century, in large part because no one thought there was much beyond that distance worth claiming.

In 1945, to tap newly reachable offshore oil resources, President Harry Truman unilaterally proclaimed that the US boundary was henceforth extended to its continental shelf. The pronouncement prompted other countries to take similar stands and inevitably led to more than a little confusion about what exactly constituted a continental shelf. Four decades later, the UN created the Law of the Sea treaty and defined the term more precisely. Countries were given 10 years after ratification to submit maps to the UN with their proposed boundaries — a deadline fast approaching for many nations.

So far, the UN's Commission on the Limits of the Continental Shelf has received petitions for boundary extensions from nine countries and given recommendations on three of them. But many more nations are likely to file soon, and the UN will almost certainly find itself faced with overlapping claims to the rich Arctic — particularly near the area Russia mapped before brazenly planting its flag.

The US is the one industrialized country that has yet to ratify the accord, mainly because some Republican senators opposed to extending international law have long stood in the way. But with oil prices high, and Arctic bounty seeming ever more reachable, President Bush has voiced support, and most experts expect the Senate to vote for ratification. Then, the quicker Washington can submit a claim, the quicker it can use its new resources. That's why the State Department is beginning the process of assessing the CCOM maps — beautiful images that show the ocean bottom as a world of canyons and rocky walls, all rendered in a rainbow of colors that delineate depths. When Gardner pulls up a profile of the continental shelf south of the Gulf Coast, facing west, the deep ocean floor spreads out on the left side of his computer screen, while the last bits of the continental shelf rise in a jagged saw-tooth pattern to the right. He can then zoom in close, looking for the foot of the slope. Eventually, diplomats and scientists will use a complex formula to draw property lines out beyond the standard 200-nautical-mile zone. "They're going to have their work cut out for them," he says. "Our job is to give them the science."

For that to happen, Gardner needs to spend more time on the boat. On a muggy morning last summer, the vessel Northern Resolution cut an imposing figure churning south from the shipyards of Pinto Island, Alabama, through the gunmetal-colored waters of Mobile Bay, and into the Gulf of Mexico. Gardner's itinerary on this cruise, his second of three last year, covered more than 20,000 square miles.

Out on the sun-scorched deck, the breeze was hot and thick, pushing low-rolling breakers back toward the shore. Belowdecks, the stale air was chilled with AC and full of the low, rumbling hum of the ship's engines. Gardner was all smiles. "I've been at sea long enough to know that from up there oceans all look the same," Gardner says. "But down here, we get to see something for the first time."

Geoffrey Gagnon (geoffrey.gagnon@gmail.com) wrote about Penn & Teller in issue 14.11.

FEATURE Russia Contests Borders With Canada, Denmark and the United States The Last Great Landgrab