Group items tagged

"Recognising ocean acidification in deep time: An evaluation of the evidence for acidification across the Triassic-Jurassic boundary Sarah E. GreeneCorresponding author contact information, 1, E-mail the corresponding author, Rowan C. Martindale1, E-mail the corresponding author, Kathleen A. Ritterbush E-mail the corresponding author, David J. Bottjer E-mail the corresponding author, Frank A. Corsetti E-mail the corresponding author, William M. Berelson E-mail the corresponding author Department of Earth Sciences, University of Southern California, Los Angeles, California, USA 90089 Received 22 July 2011. Accepted 17 March 2012. Available online 5 April 2012. While demonstrating ocean acidification in the modern is relatively straightforward (measure increase in atmospheric CO2 and corresponding ocean chemistry change), identifying palaeo-ocean acidification is problematic. The crux of this problem is that the rock record is a constructive archive while ocean acidification is essentially a destructive (and/or inhibitory) phenomenon. This is exacerbated in deep time without the benefit of a deep ocean record. Here, we discuss the feasibility of, and potential criteria for, identifying an acidification event in deep time. Furthermore, we investigate the evidence for ocean acidification during the Triassic-Jurassic (T-J) boundary interval, an excellent test case because 1) it occurs in deep time, beyond the reach of deep sea drilling coverage; 2) a potential trigger for acidification is known; and 3) it is associated with one of the 'Big Five' mass extinctions which disproportionately affected modern-style invertebrates. Three main criteria suggest that acidification may have occurred across the T-J transition. 1) The eruption of the Central Atlantic Magmatic Province (CAMP) and the associated massive and rapid release of CO2 coincident with the end-Triassic mass extinction provide a suitable trigger for an acidification event (

Science 8 July 2011: Vol. 333 no. 6039 pp. 173-175 Galaxy Zoo Volunteers Share Pain and Glory of Research 1. Daniel Clery A project to "crowdsource" galactic classifications has paid off in ways the astronomers who started it never expected. Figure View larger version: * In this page * In a new window Space oddity. Greenish "voorwerp" spotted by a Dutch volunteer still intrigues scientists. "CREDIT: NASA, ESA, W. KEEL (UNIVERSITY OF ALABAMA), AND THE GALAXY ZOO TEAM" The automated surveys that are becoming increasingly common in astronomy are producing an embarrassment of riches for researchers. Projects such as the Sloan Digital Sky Survey (SDSS) are generating so much data that, in some cases, astronomers don't know what to do with them all. SDSS has compiled a list of more than 1 million galaxies. To glean information about galaxy evolution, however, astronomers need to know what type of galaxy each one is: spiral, barred spiral, elliptical, or something else. At present, the only reliable way to classify galaxies is to look at each one. But the SDSS list is so long that all the world's astronomers working together couldn't muster enough eyeballs for the task. Enter the "wisdom of crowds." An online effort called Galaxy Zoo, launched in 2007, set a standard for citizen-scientist participation projects. Zealous volunteers astonished the project's organizers by classifying the entire catalog years ahead of schedule. The results have brought real statistical rigor to a field used to samples too small to support firm conclusions. But that's not all. Buoyed by the curiosity and dedication of the volunteers, the Galaxy Zoo team went on to ask more-complicated classification questions that led to studies they hadn't thought possible. And in an online discussion forum on the Galaxy Zoo Web site, volunteers have pointed to anomalies that on closer inspection have turned out to be genuinely new astronomical objects. "I'm incredibly impres