Barrow Canyon: Where Atlantic Meets Pacific

Want to dip your toes in the Atlantic Ocean without leaving Alaska? Just head north from Barrow and pay a visit to Barrow Canyon.

You've never heard of Barrow Canyon? It's an impressive, V-shaped valley that's 150 miles long and 15 miles wide. The valley floor lies 1,200 feet below the peaks that rise above it.

Don't feel bad about your apparent ignorance of Alaska geography. Barrow Canyon, one of the places where the Atlantic Ocean meets the Pacific Ocean, is deep under salt water. It's the type of feature studied by Tom Weingartner, an assistant professor at the University of Alaska Fairbanks Institute of Marine Science. Weingartner is a physical oceanographer, a person who has a different world view than most of us because his includes the incredible mountains, valleys and plains of the ocean bottom.

Barrow Canyon cuts a northeast-southwest swath through the earth's surface about 20 miles north of Barrow. The ocean above Barrow Canyon, covered with sea ice for up to 10 months a year, shows no trace of the dramatic scenery below.

Barrow Canyon is an example of a "submarine canyon," an underwater gorge that looks like a deep, stream-cut valley. While the word "submarine" refers to the fact that it's underwater, Barrow Canyon was actually used by a nuclear-powered submarine. In 1957, The crew of the Nautilus used Barrow Canyon to slip from the Chukchi Sea to the deeper Beaufort Sea during the Nautilus's trip under the polar ice cap.

The canyon provides a pathway for more than just submarines. Because it connects the relatively shallow table of the Chukchi Shelf to the deeper Beaufort Sea, Barrow Canyon serves as sort of a drainage ditch for the Chukchi Sea in the winter. Researchers have tracked cold, dense water from the Chukchi Sea flowing northeast through the canyon to the Beaufort Sea.

Currents occasionally flow southwest through the canyon, however. That's where the Atlantic Ocean water shows up. The Atlantic water travels quite a distance to Barrow Canyon.

The trip begins as currents carry Atlantic Ocean water northward between Scotland and Iceland. The water continues northeast past Norway, where it passes the Arctic Circle. There, it flows on around northern Russia to the Arctic Ocean. Once it's staged in the Arctic Ocean, the Atlantic water is occasionally forced though Barrow Canyon by underwater waves generated by arctic surface winds or forces within the ocean.

Weingartner and his colleagues maintain instruments that hang deep within Barrow Canyon. Sensors pick up the unique taste of Atlantic water, which is saltier and warmer than surrounding Arctic and Pacific Ocean waters. The Atlantic water interests scientists because as it flows around the Arctic Ocean to Alaska it can transport pollutants spit out in northern countries to the shallow sea shelves of Eurasia.

The Atlantic water's relative warmth can also be a problem, Weingartner said. Even though it's just a few degrees above freezing, Atlantic water is warmer than Chukchi Sea or Beaufort Sea water. A couple degrees of temperature might not seem like much, but it means a lot to sea ice floating at the surface. If the sea ice wasn't somehow insulated from Atlantic Ocean water, more sea ice would melt. If more sea ice melted, more heat from the ocean would be released into the atmosphere, an effect that could be felt around the globe.

In the Arctic Ocean, an 800-foot thick blanket of cold water insulates the sea ice from the heat within the Atlantic water. In this buffering layer, known as a halocline, the ocean's salinity increases very rapidly with depth. Although both haloclines and Atlantic water occur throughout oceans in the circumpolar north, Barrow Canyon offers a close-to-home chance to study them both.

While Weingartner and other oceanographers ponder the global significance of warmish Atlantic Ocean water in Barrow Canyon, I can't help thinking about its commercial potential. I picture an entrepreneur offering tourists an exotic adventure to "scenic Barrow Canyon, where the Atlantic meets the Pacific." All it would take is a business license and a submarine.