Professor Thomas Stocker of the University of Bern in Switzerland is one of the principal investigators of EPICA (European Programme for Ice Coring in Antarctica.) Stocker explains that EPICA, a joint ESF- European Commission (EC) effort funded by the Commission and 10 national agencies, has put Europe in a leading position in ice core research, in which specially designed drilling technology is used to obtain continuous ice sequences 3.8 thousands of metres in length.
A series of EPICA papers in prestigious journals such as Nature and Science are evidence of its world importance. The principle behind ice coring is straightforward. Snow falls in Greenland and the Antarctic, but conditions there are too cold for it to melt. In most places it will eventually be carried away by glacial movement, but it is possible to find areas where the snow has piled up for hundreds of thousands of years, turning to ice as the weight of later snowfall builds up on top.
Drilling out a core of such ice reveals the past in a neat sequence of millennia. Better still, the ice contains information about the past. It includes trapped air bubbles that can be analysed to reveal the composition of the ancient atmosphere. Layers of ash reveal ancient volcanic eruptions. And the ratio of different isotopes of oxygen in the ice is a virtual thermometer that tells us past temperatures. The more of the lighter isotope, oxygen 16, there is, the colder it was.
Stocker says: “Ice-drilling is an area in which Europe has taken a decisive technological and scientific lead in the past decade. We now have a continuous record of 800,000 years of climate history, thanks to EPICA and other European initiatives.”
These ice cores directly illuminate current climate debates. As Stocker points out, air bubbles allow us to measure how much methane and carbon dioxide there was in the air when the snow fell. These – especially carbon dioxide – are the principal greenhouse gases in the Earth’s atmosphere. It is clear that they are now at their most abundant for hundreds of thousands of years. By contrast, the most-used direct measurements of atmospheric carbon dioxide, made on Hawaii, only date back to 1958. So as Stocker says: “EPICA results form a cornerstone of the current climate debate.”
EPICA has been responsible for drilling and investigating two deep ice cores in Antarctica. One was at a site called Dome C, and the other at Kohnen research station in Queen Maud Land. At Dome C, ice was drilled out to a depth of 3270m, stopping in December 2004 just 5m above the rocky basement below. Because of the immense pressure at this depth, there is liquid water above the rock, so drilling was stopped to avoid polluting it. At Kohnen station, drilling was completed in January 2006 at a depth of 2774m, where the ice was estimated to be 150,000 years old.
Stocker says that this research is being pushed forward under the umbrella of the current International Polar Year, in which ESF is a contributor. Recently a new project called NEEM (North Greenland Eemian Ice Drilling) has been launched to investigate the Eemian period in Earth history. This warm period from about 130,000 to 115,000 years ago shares similarities with an imminent future greenhouse Earth, and it had sea levels about 7m higher than those we observe today. The NEEM project forms part of IPICS, the International Partnership in Ice Core Sciences. Stocker explains that one of the aims of IPICS is to find the oldest ice in Greenland, probably in the north-west of the island, so that we can get a clear comparison between Arctic and Antarctic narratives of Earth history.
While these cores still have plenty to tell us, Stocker and his colleagues are in little doubt about the overall message. They think that climate “forcing” by greenhouse gases is a very real phenomenon: in other words, that rising greenhouse gas concentrations drive the Earth’s temperature upwards in a very direct way. So the ice cores now deposited in cold “stores” around the world have a clear message for us all.
In times of climate change: What a lake’s colour can tell about its condition
21.09.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?
21.09.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
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22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy