Trace elements such as iron, manganese and zinc are an integral part of the biogeochemical processes on the Earth's surface. As micronutrients, they play an essential role for the growth of all kinds of organisms and thus the Earth's carbon cycle. Below ice sheets, which cover around ten percent of the Earth's land surface, larger quantities of these substances are mobilised than previously assumed. This is shown by new data from Greenland and Antarctica, which were collected and analysed by an international research team led by Jon Hawkings from the GFZ German Research Centre for Geosciences in Potsdam and Florida State University (USA). They provide important insights into previously unknown processes at the boundary of ice, meltwater and rock. Because the ice masses are significantly influenced by global warming, new perspectives are emerging on the consequences climate change has for critical biogeochemical processes, including those in surrounding ecosystems such as oceans, lakes and wetlands. The study is published today in the journal PNAS.
Under the Earth's ice sheets melt water forms an extensive hidden wetland of rivulets, rivers and lakes. During the last forty years, over 400 subglacial lakes have been discovered in Antarctica alone; some as large as the Great Lakes of North America. At the boundary between ice, water and rock, a complex ensemble of chemical, physical and microbiological forces is at work, breaking up and grinding rock and releasing trace elements into the meltwater which is carried downstream. These chemical elements occur only in very low concentrations, hence the name. Nevertheless they are - like vitamins - essential as nutrients for all living things.
Read more at GFZ German Research Centre for Geosciences
Photo Credit: Jon Hawkings