"CSI-like" techniques, used on minerals, are revealing the steps that led to evolution of the atmosphere on Earth. President of the Mineralogical Society of America, Douglas Rumble, III, of the Carnegie Institutions Geophysical Laboratory, describes the suite of techniques and studies over the last five years that have led to a growing consensus by the scientific community of what happened to produce the protective ozone layer and atmosphere on our planet. His landmark paper on the subject appears in the May/June American Mineralogist.
"Rocks, fossils, and other natural relics hold clues to ancient environments in the form of different ratios of isotopes--atomic variants of elements with the same number of protons but different numbers of neutrons," explained Rumble. "Seawater, rain water, oxygen, and ozone, for instance, all have different ratios, or fingerprints, of the oxygen isotopes 16O, 17O, and 18O. Weathering, ground water, and direct deposition of atmospheric aerosols change the ratios of the isotopes in a rock revealing a lot about the past climate." Rumbles paper describes how geochemists, mineralogists, and petrologists are studying anomalies of isotopes of oxygen and sulfur to piece together what happened to our atmosphere from about 3.9 billion years ago, when the crust of our planet was just forming and there was no oxygen in the atmosphere, to a primitive oxygenated world 2.3 billion years ago, and then to the present.
The detective work involves a pantheon of scientists who have analyzed surface minerals from all over the globe, used rockets and balloons to sample the stratosphere, collected and studied ice cores from Antarctica, conducted lab experiments, and run mathematical models. The synthesis from the different fields and techniques points to ultraviolet (UV) light from the Sun as an important driving force in atmospheric evolution. Solar UV photons break up molecular oxygen (O2) to produced ozone (O3) leaving a tell-tale isotopic signature of excess 17O. The ozone layer began to form as the atmosphere gained oxygen, and has since shielded our planet from harmful solar rays and made life possible on Earths surface.
Douglas Rumble, III | EurekAlert!
NASA examines Peru's deadly rainfall
24.03.2017 | NASA/Goddard Space Flight Center
Steep rise of the Bernese Alps
24.03.2017 | Universität Bern
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy