Late Ordovician geographic patterns of extinction compared with simulations of astrophysical ionizing radiation damage

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Accepted for publication in Paleobiology. 16 pages, 2 figures

Scientific paper

Based on the intensity and rates of various kinds of intense ionizing radiation events such as supernovae and gamma-ray bursts, it is likely that the Earth has been subjected to one or extinction level events during the Phanerozoic. These induce changes in atmospheric chemistry so that the level of Solar ultraviolet-B radiation reaching the surface and near-surface waters may be doubled for up to a decade. This UVB level is known from experiment to be more than enough to kill off many kinds of organisms, particularly phytoplankton. It could easily induce a crash of the photosynthetic-based food chain in the oceans. Regularities in the latitudinal distribution of damage are apparent in simulations of the atmospheric changes. We previously proposed that the late Ordovician extinction is a plausible candidate for a contribution from an ionizing radiation event, based on environmental selectivity in trilobites. To test a null hypothesis based on this proposal, we confront latitudinal differential extinction rates predicted from the simulations with data from a published analysis of latitudinal gradients in the Ordovician extinction. The pattern of UVB damage always shows a strong maximum at some latitude, with substantially lower intensity to the north and south of this maximum. We find that the pattern of damage predicted from our simulations is consistent with the data assuming a burst approximately over the South Pole, and no further north than -75 degrees. We predict that any land mass (such as parts of north China, Laurentia, and New Guinea) which then lay north of the equator should be a refuge from UVB effects, and show a different pattern of extinction in the first strike of the end-Ordovician extinction, if induced by such a radiation event.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Late Ordovician geographic patterns of extinction compared with simulations of astrophysical ionizing radiation damage does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Late Ordovician geographic patterns of extinction compared with simulations of astrophysical ionizing radiation damage, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Late Ordovician geographic patterns of extinction compared with simulations of astrophysical ionizing radiation damage will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-658412

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.