Greenland’s fastest-flowing and fastest-thinning glacier just recently tossed a genuine brain bender at researchers, who understood that rather of diminishing, the glacier is in fact growing thicker, they reported in a brand-new research study.
The glacier– called Jakobshavn, which rests on Greenland’s west coast– is still adding to water level increase, however it’s losing less ice than anticipated. Rather of thinning and pulling away inland, its ice is thickening and advancing towards the ocean, the scientists discovered.
The huge concern: Why is this taking place? [Images: Greenland’s Gorgeous Glaciers]
After much sleuthing, a group of researchers from the United States and the Netherlands discovered that the glacier is most likely growing due to chillier ocean currents. In 2016, an existing that goes by Jakobshavn glacier was cooler than typical, making waters near the glacier the coldest they ‘d been because the mid-1980 s.
This cooler current originated from the North Atlantic Ocean, more than 600 miles (966 kilometers) south of the glacier, according to information from NASA’s Oceans Melting Greenland (OMG) objective and other observations.
The finding took the researchers totally by surprise. “In the beginning, we didn’t think it,” research study lead scientist Ala Khazendar, a researcher at NASA’s Jet Propulsion Lab in Pasadena, California, stated in a declaration “We had practically presumed that Jakobshavn would simply keep going on as it had more than the last 20 years.” However the cold water isn’t a one-off. Information from OMG reveals that the water has actually been cold now for 3 years in a row.
It appears that the cold water is the outcome of an environment pattern called the North Atlantic Oscillation (NAO), that makes the northern Atlantic Ocean gradually change in between waters that are warm and cold about as soon as every 20 years, the scientists stated. The cold stage simply recently began, and has actually cooled the Atlantic Ocean in basic, they stated. In addition, some additional cooling of the waters around Greenland’s southwest coast assisted keep the glacier cold.
However this crisp modification will not last permanently. As soon as the NAO environment pattern turns back, the Jakobshavn will likely begin melting faster and thinning once again, the scientists stated.
” Jakobshavn is getting a short-term break from this environment pattern,” Josh Willis of the Jet Propulsion Lab and the primary private investigator of OMG, stated in the declaration. “However in the long run, the oceans are warming. And seeing the oceans have such a big effect on the glaciers is bad news for Greenland’s ice sheet.”
Big ice loss … then little gain
Researchers have saw Jakobshavn with issue for years. After losing its ice rack in the early 2000 s (an ice rack requires a glacier to stream more gradually into the ocean, like dirt blocking a drain), Jakobshavn started losing ice at a worrying rate. In Between 2003 and 2016, its density (from leading to bottom), diminished by 500 feet (152 meters).
However in 2016, the waters streaming from Greenland’s southern pointer to its western side cooled by more than 2.7 degrees Fahrenheit (1.5 degrees Celsius). On the other hand, the NAO environment pattern triggered the Atlantic Ocean near Greenland to cool by about 0.5 F (1 C) in between 2013 and2016 By the summer season of 2016, these cooler waters reached the glacier, and they are most likely the factor that Jakobshavn slowed its rate of ice loss to the ocean, the scientists stated. [Image: Greenland’s Dramatic Landscape]
In all, Jakobshavn grew about 100 feet (30 m) taller in between 2016 and 2017, the scientists discovered. However, as pointed out, the glacier is still adding to ocean level increase worldwide, as it’s still losing more ice to the ocean than it is acquiring from snow build-up, the scientists stated.
The findings clarify just how much ocean temperature levels can impact glacier development, stated Tom Wagner, a NASA Head office program researcher for the cryosphere, the frozen part of Earth.
” The OMG objective released brand-new innovations that enabled us to observe a natural experiment, much as we would carry out in a lab, where variations in ocean temperature levels were utilized to manage the circulation of a glacier,” Wagner, who was not associated with the research study, stated in the declaration. “Their findings– particularly about how rapidly the ice reacts– will be necessary to predicting water level increase in both the near and long run.”
The research study was released online March 25 in the journal Nature Geoscience
Initially released on Live Science