The core, which is longer than 1 1/2 football fields, is the longest extracted from an arctic glacier in the United States, according to Matt Nolan, an associate professor at the University of Alaska Fairbanks Institute of Northern Engineering who has led research at McCall Glacier for the past six years. The sample spans the entire depth of the glacier and may cover 200 years of history, he said.
“What we hope is that the climate record will extend back into the Little Ice Age,” said Nolan. “Up until the late 1800s these glaciers were actually growing.”
Since then, arctic glaciers have been shrinking at an increasing rate, he said. “There is no doubt that this is due to a change in climate, but until now we can only guess at the magnitude of that change. Within these cores, we will hopefully capture this shift in climate quantitatively, and we’re glad to have recovered them now before more of this valuable record melts and flows into the Arctic Ocean.”
Ice core samples offer a window into past climate using clues, such as gas bubbles or isotopes of oxygen and hydrogen, locked in the ice when it formed. In addition, debris in the ice, such as layers of volcanic ash and pieces of organic material such as insects, can help scientists draw a timeline through the depth of the glacier.
Because McCall Glacier has been studied extensively since the International Geophysical Year in1957-58, the research history there offers a unique opportunity to compare ice core data with a wealth of related information, such as ice temperature and speed, air temperature and snowfall, and models of how the glacier changes within those parameters. Those comparisons with the modern parts of the ice core can help scientists better understand changes in the older sections, Nolan said.
“Due to its remote location, long-term instrumental climate data here are sparse to nonexistent, so ice cores from this glacier are one of our few means to determine climate variations in this huge region over the past few hundred years,” Nolan said. “We are also quite fortunate and privileged to be granted permission for this work. Research at McCall Glacier predates the formation of the refuge and meshes well with scientific aspects of the refuge’s mission to conduct long-term ecological research.”
A team using a drill from the Ice Core Drilling Service at the University of Wisconsin-Madison pulled the cores from the glacier, one meter at a time, for nearly two weeks straight, despite storms strong enough to break and blow away some of their tents. About midway down, drillers hit an aquifer in the ice, which filled the borehole with water and complicated the drilling effort.
“The drill team did an excellent job of making their tools work in challenging conditions, in particular drilling the last 80 meters of core under water,” Nolan said. “This is a very unusual situation for ice coring, as most cores are taken from summits of cold, dry polar ice sheets not warm, flowing valley glaciers.”
At 150 meters, drillers hit a rock at what the team believes was the bottom of the glacier, based on radar measurements of ice depth.
The ice cores were flown to Fairbanks and are being housed at the Alaska Ice Art Museum until the fall, when glaciologists will return from the field to begin analysis.
The McCall Glacier project is part of UAF’s contribution to research efforts during the fourth International Polar Year. Nolan’s research at McCall Glacier is funded by the National Science Foundation and is part of a cooperative effort, involving 15 other nations, to gain a better understanding of the dynamic response of arctic glaciers to recent climate change. IPY is an international endeavor that is focusing research efforts and public attention on the Earth’s polar regions. Other partners on the field team included the University of Silesia in Poland and the Kitami Institute of Technology in Japan. Additional core analysis will be performed at Ohio State University and the Free University of Brussels in Belgium.
CONTACT: Marmian Grimes, UAF public information officer, at 907-474-7902 or via e-mail at email@example.com.
Marmian Grimes | EurekAlert!
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
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy