Our Mission: July 1 - August 10, 2007
For the first time in the history of humankind, a scientific team—using unique underwater and under-ice vehicles—will attempt to reach the bottom of the Arctic Ocean to find seafloor hydrothermal vents. Join Expedition 11 this summer on a potentially historic and groundbreaking (and certainly icebreaking) research cruise aboard the Swedish icebreaking ship Oden.
We know so little about the Arctic Ocean seafloor, because exploration of the Arctic is so difficult. At the top of the world, the Arctic Ocean is cold, remote, and covered in darkness for half the year. It’s hard enough to get onto the ice-covered ocean. It’s even harder to get under it and down to its seafloor.
For this 40-day cruise to the Gakkel Ridge in the eastern Arctic Ocean, engineers have built two new robotic underwater vehicles called PUMA and JAGUAR. They are autonomous, which means they have no pilot and can swim on their own. PUMA and JAGUAR are designed to be put into holes in the sea ice (that’s the relatively easy part) and to explore the deep reaches of the Arctic Ocean. Many hours later, they will have to find their way back to another hole in the ice and be recovered by the Oden.
AUVs (short for Autonomous Underwater Vehicles) have been deployed in open ocean waters off Antarctica, sent under the ice, and recovered in open waters. That is risky enough: Quite recently, one AUV dispatched under Antarctic sea ice never returned. But recovering AUVs in an ice-covered ocean has never been tried before. Will PUMA and JAGUAR successfully navigate through all the difficult challenges on their first experimental mission?
If so, scientists are excited by the possibilities that what lies on the Arctic Ocean floor may be different from what they have found in other oceans—including deep-sea life forms never seen before, or “living fossils” of species that existed when life on Earth was just beginning to evolve. You can follow what happens on this cruise each day on Dive & Discover and perhaps witness history unfold.
The Gakkel Ridge
It wasn’t until 2001, on the maiden voyage of the U.S. Coast Guard icebreaker Healy, that scientists first detected tantalizing clues that the Arctic seafloor may be unlike the seafloors of the more-explored Atlantic and Pacific Oceans.
The Gakkel Ridge is the deepest mid-ocean ridge, ranging from 3 to 5 kilometers (1.8 to 3 miles) deep, and it also perhaps the slowest-spreading ridge. Consequently, scientists had predicted that there wouldn’t be much volcanic activity on it.
Much to their surprise, scientists aboard the 2001 cruise dredged up rocks from the Gakkel Ridge that appear to have been transformed by fascinating chemical reactions between seawater and crustal rocks heated by volcanism. These chemical reactions produce hot, mineral-rich fluids that spew like geysers from seafloor vents. The fluids nourish vibrant communities of unusual life forms.
However, volcanoes occur only on isolated parts of the Gakkel Ridge. Along other sections, the 2001 cruise dredged up rocks that are normally found deeper down, in Earth’s mantle. These rocks have a different composition, so the chemical reactions between Gakkel Ridge rocks and seawater may also be different, producing chemicals such as methane and hydrogen, which can support forms of life different from those typically found on other parts of the mid-ocean ridge.
Sensors on the Healy’s dredging lines also detected hints of warmer water, chemicals, and particles that are present in plumes of vent fluids, which billow out far and wide from small vents like smoke from smokestacks. The goal of the Gakkel Ridge expedition is to see if active vents are really there, to find them, and to learn if they, and the communities of life around them, are different.
PUMA will be deployed first, acting like a helicopter in search mode. It will survey wide areas with sonar mapping tools and sensors to detect telltale temperature, chemical, or particle signals of hydrothermal plumes. Then it will track the plumes back to their sources. JAGUAR will be deployed next, acting like a helicopter in hover mode above vents. It will use sonar to create maps of vent sites and its camera and lighting systems can collect images of the vents and the animals that live around them.
Sampling on the seafloor under ice presents another challenge because the icebreaker cannot move fast or freely, and openings in the ice usually freeze up quickly. Researchers will only have a few, short opportunities to lower a sampling device on a wire to the seafloor. So we have designed and built another experimental vehicle called CAMPER, (short for “camera sampler”), a sled that the ship tows on a line near seafloor vents. CAMPER is equipped with cameras and chemical sensors, as well as devices for quickly grabbing hard samples (such as rocks or clams) and a “slurp gun” that can vacuum in samples of fluids or shrimp.
Since hydrothermal vents were first discovered in 1977, scientists have learned that on the seafloor, as on land, distinct animal populations have evolved in different regions.
Will Arctic vents have shrimp, as Atlantic vents do, or clams, as Pacific vents do?
The Arctic Ocean is a missing piece in the puzzle. Will it have species similar to neither?
There is reason to think that it might. We think the Arctic Ocean became enclosed about 65 million years ago and since then has not had deep-water connections with neighboring oceans. So, animals in the Arctic may have evolved in isolation, producing unusual species that are found nowhere else—much the way kangaroos and koalas did only in Australia.
Gakkel Ridge rocks also may be quite similar to rocks that erupted billions of years ago during the early part of Earth’s history, so life at Arctic vents may also resemble early life on our planet.
Join our team as we send AUVs beneath the ice-covered Arctic Ocean for the first time. Whatever happens and whatever we find is guaranteed to be unprecedented.