If global temperatures keep rising, it is increasingly likely we will experience a “thawing permafrost,” a rapid global loss of one of the planet’s most important sea-floor productivity systems, a new study concludes.
Thawing permafrost means its bottom sediment is lighter in weight. It also means that frozen water could unearth thousands of pounds of sediments beneath the permafrost’s underlying ice, which could reveal ancient sea beds full of ivory, obsidian and more than 100 other minerals.
“The process of thawing permafrost changes the immediate top-story from permafrost to sediment and then into the sea floor, where we get lead to coal and other materials that could be frozen for tens to hundreds of thousands of years in a deposit,” said [Douglas] Dreisinger, a meteorologist with the University of Wisconsin-Madison.
In the study published Thursday in the journal Science, Dreisinger and his colleagues from the University of Washington and the University of Florida estimated the mass of sediment on the water-worn permafrost of Lake Superior and found those sizes increased over time. The researchers saw “serious feedback” as warmer conditions led to a thawing underneath the upper sheet that accelerated sediment accumulation.
Because of increased snow cover and lower temperatures in the northern hemisphere in recent years, “we’re getting more time with these potential values, and we’re able to observe changes,” Dreisinger said. “If the temperature were to continue at the same level, we would actually see an acceleration of the increase of sediment if we want to get that much more sediment.”
There are fewer open lands available as the Arctic Basin warms and as the ocean waters begin to cover more of the top of the sea ice, he said. The whole process increases the risk of warmer temperatures causing a thawing of permafrost.
Increasingly warm temperatures have already melted more than 14 billion tons of ice from the Arctic Ocean each summer, or about a third of the entire ice cover that existed on Earth in 1979, according to the National Snow and Ice Data Center.
Among those valuable and potentially valuable resources is the color-coded golden-yellow, reddish-orange and black of the terrestrial arcatite, an extremely abundant mineral found in many major seas, said Andrew Sands, a geochemist with Rockefeller University who co-authored the Science study. Arcatite is used in everyday products such as the toothpaste and blue jeans.
At least 30 sites have been discovered in warmth sea beds that contain 3,000-year-old dental enamel or vein impressions that reveal dental burns – which have been tied to the earlier exploration and industrialization of late in the 19th and early 20th centuries. Palladium, iron oxide and other minerals have been found below the surface of the Arctic Ocean, too.
“You have [deep sea] floors that are really warm, and in a lot of cases we’re finding that these are areas that people shouldn’t have been into, that we shouldn’t have been exploring for so long,” Sands said.
Among the world’s most advanced parabolic telescopes, North America’s Juno space probe has discovered that a floating layer of phosphorous has arrived on the sun-soaked moon Europa. Knowing this, NASA is planning a mission to get a closer look at the plucky world’s global oceans.
“If you talk to the guys with the Juno team and ask them about these results, they will readily note that these are part of their overall efforts to get some insight into Europa’s properties and its ocean,” Sands said.
Scientists had for decades known oceans exist on Europa, but many telescopes could only see it from within the outer edges of a dark region of the moon, because it too was below the surface of the dark ice shell. But because new images show the actual surface, this new information may lead scientists to advance our knowledge of it.
“The dark interior appears to be so permeable,” Sands said. “Knowing that, there are certainly indications that is an incredible potential place to search for a subsurface ocean.”