College of Copenhagen
Ice core analysis: Researchers from the part Physics of Ice, Local weather and Earth (PICE) on the Niels Bohr Institute, College of Copenhagen, have succeeded in making a way to enlighten an in any other case darkish interval in local weather historical past. Working with the ice core ReCap, drilled near the coast in East Greenland, postdoc Marius Simonsen puzzled why the mud particles from the interglacial interval – the hotter time frame between the ice ages – had been a number of instances greater than the mud particles from the ice age. His analysis led to the invention of a way capable of map the development of the glaciers in chilly intervals and the melting in hotter intervals. This information is essential for the local weather fashions we use to foretell sea stage rise. The result’s now printed in Nature Communications.
The bigger particles of mud don’t journey far – they arrive from East Greenland
Based mostly on the speculation that the larger mud particles within the ice couldn’t have come from afar, the then PhD pupil, Marius Simonsen, examined the mud at choose areas on the coast of East Greenland near the drill website. The chemical composition turned out to be just like the bigger particles within the ice. The smaller particles of mud caught within the ice, however, journey from Asia, blown to Greenland by mud storms. In different phrases, the larger particles of mud within the ice should imply presence of naked land near the drill website. The ice consists of annual layers, like the expansion rings in a tree, so the distribution of huge and small mud particles may be linked to the development and melting of the ice. Giant particles imply naked land within the neighborhood, small particles imply the land is roofed in ice. The tip of the ice age, the place the ice cap is receding, is nicely defined scientifically, Marius Simonsen explains. “However it is extremely troublesome to retrieve information on the interval earlier than the ice age. The ice is an especially robust pure drive, so it grinds away every part when advancing. However with the brand new methodology, we now have information on the development of the ice. Unexpectedly, we now have a hyperlink to data on how rapidly we enter an ice age, in a means we by no means used to have”.
Gaining data on Glacier response to atmospheric content material of CO2 is essential
You will need to know extra about how glaciers react to modifications within the environment, and relatively lots is understood on the composition of the environment throughout the ice age. The outcomes from the brand new methodology can now be used to match the response within the plenty of ice to modifications within the atmospheric content material of greenhouse gasses like CO2. Marius Simonsen says: “The glaciers receded in the beginning of the current interglacial, identical to they do right this moment due to local weather change. The 2 eventualities are usually not solely comparable, as a result of there was rather more inland ice then than now by the coast in East Greenland the place the ice core is drilled. By no means the much less, the outcomes are very attention-grabbing certainly when making local weather fashions, as a result of the fashions have to be examined by comparability to actuality. And within the new methodology we’ve acquired an anchor level in a interval about which not a lot scientific data existed”. The tactic helps placing constraints on our data on the affect of greenhouse gasses on ice melting and, consequently, sea stage.
The tactic can present us with new data on how briskly the glaciers recede
Helle Astrid Kjær, Assistant professor in PICE, says the target of PICE now could be to make the most of the brand new methodology at different areas so we will collect extra information on the modifications of glaciers previously. The researchers are already planning new drill websites in North East Greenland and Canada. It is vitally possible that development and melting of the ice there’s completely different from East Greenland. “Maybe, with the brand new methodology, we’re capable of see how briskly the ice age got here in from the north and moved south”, Helle Astrid Kjær says.
It’s a precondition for the feasibility of the strategy that naked land exists within the neighborhood of the drill website, so mud particles may be discovered. This was the case over the last interglacial because the temperature then, app. 115,000 years in the past, was as much as eight levels C. hotter than right this moment, in line with a former research from the Niels Bohr Institute. Therefore, the strategy will most certainly be usable in North East Greenland and Canada. The researchers on the Niels Bohr Institute are already establishing new collaborations with Canadian researchers primarily based on the brand new methodology.
Drilling of the ice core ReCap was supported by The Danish Nationwide Analysis Basis, the American Nationwide Science Basis, the German Alfred Wegener Institute and the European Union Horizon 2020 Analysis and Innovation Programme. The measurements of mud had been supported by the EU funding ice2ice and Horizon 2020 – TIPES.