Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Carbon cycle was already disrupted millions of years ago

19.04.2006


Dutch researcher Yvonne van Breugel analysed rocks from seabeds millions of years old. Carbon occurs naturally in two stable forms; atomic mass 12 (99 percent) and atomic mass 13 (1 percent). Episodes in the Jurassic and Cretaceous periods were characterised by a relatively strong increase in 12C. The analyses have shown that this was caused by a sudden large-scale release of carbon from stocks stored in the ocean floor or peats and bogs.



The atmospheric carbon dioxide concentration is increasing as a consequence of the large-scale use of fossil fuels in the industrial era. This has apparently brought about a stronger relative increase in the light carbon isotope 12C. Due to this the ratio of the stable carbon isotopes 13C/12C has show a clearly measurable decrease of 0.1%. However in the Jurassic and Cretaceous periods, 180 and 120 million years ago, there were periods with a shift four times as large in a period of just several tens of thousands of years. Where did all of that light carbon suddenly come from?

Van Breugel investigated chemical fossils of marine algae and land plants from sediments deposited in the aforementioned periods. Plants and algae assimilate CO2 from the air and water. Consequently changes in the isotope ratio are recorded in organic material. These chemical fossils have been well preserved because large parts of the oceans in the Jurassic and Cretaceous periods contained little (if any) oxygen.


In sediment cores from various widely-separated areas Van Breugel found a 0.4% decrease in the 13C/12C ratio. This means that there were large-scale changes in the carbon cycle over a short geological timescale of several tens of thousands of years. From the results Van Breugel deduced that large quantities of 12C in the form of CO2 or methane were suddenly released into the atmosphere.

This could have been the result of methane being released from gas hydrates which were buried in the ocean floor. It is not clear which mechanism was responsible for this. Methane could also have been formed under high pressure in coal seams and then subsequently released upon coming into contact with magma. A third option is that carbon from organically-rich sediment came into contact with hot magma. As a result of this the organic molecules combusted into CO2 and water.

Dr Yvonne van Breugel | alfa
Further information:
http://www.nwo.nl/nwohome.nsf/pages/NWOA_6NJHM4_Eng

More articles from Ecology, The Environment and Conservation:

nachricht Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen

nachricht A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

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

Im Focus: Highly precise wiring in the Cerebral Cortex

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...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

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...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

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...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>