"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!
Wandering greenhouse gas
16.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
Unique Insights into the Antarctic Ice Shelf System
14.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
20.03.2018 | Agricultural and Forestry Science
20.03.2018 | Life Sciences
20.03.2018 | Life Sciences