Climatic and biogeochemical effects of a galactic gamma ray burst

  title={Climatic and biogeochemical effects of a galactic gamma ray burst},
  author={Adrian L. Melott and Brian C. Thomas and Daniel P. Hogan and Larissa M. Ejzak and C. H. Jackman},
  journal={Geophysical Research Letters},
[1] It is likely that one or more gamma ray bursts within our galaxy have strongly irradiated the Earth in the last Gy. This produces significant atmospheric ionization and dissociation, resulting in ozone depletion and DNA-damaging ultraviolet solar flux reaching the surface for up to a decade. Here we show the first detailed computation of two other significant effects. Visible opacity of NO2 is sufficient to reduce solar energy at the surface up to a few percent, with the greatest effect at… Expand

Figures from this paper

Gamma-ray bursts and terrestrial planetary atmospheres
Results of modelling the effects on Earth-like planets of long-duration gamma-ray bursts within a few kiloparsecs are described, including increased atmospheric opacity due to build-up of nitrogen dioxide produced by the burst and enhanced precipitation of nitric acid. Expand
Gamma-Ray Bursts and the Earth: Exploration of Atmospheric, Biological, Climatic, and Biogeochemical Effects
Gamma-ray bursts (GRBs) are likely to have made a number of significant impacts on the Earth during the last billion years. The gamma radiation from a burst within a few kiloparsecs would quicklyExpand
Nitrate deposition following an astrophysical ionizing radiation event
It is suggested that this flux may have contributed nutrients to this invasion if, as hypothesized, the end-Ordovician extinction event were initiated by a GRB or other ionizing radiation event. Expand
Atmospheric Consequences of Cosmic Ray Variability in the Extragalactic Shock Model II: Revised io
[1] It has been suggested that galactic shock asymmetry induced by our galaxy's infall toward the Virgo Cluster may be a source of periodicity in cosmic-ray exposure as the solar system oscillatesExpand
Terrestrial Consequences of Spectral and Temporal Variability in Ionizing Photon Events
The effect of many astrophysical events causing atmospheric ionization can be approximated without including time development by generalizing atmospheric computations to include a broad range of peak photon energies and investigating the effect of burst duration. Expand
Late Ordovician geographic patterns of extinction compared with simulations of astrophysical ionizing radiation damage
This work focuses on gamma-ray bursts (Thorsett 1995; Scalo and Wheeler 2002), a proposed causal agent for the end-Ordovician extinction, a threat approximately competitive with, for example, that of nearby supernovae. Expand
Gamma-ray bursts as a threat to life on Earth
  • B. Thomas
  • Physics, Environmental Science
  • International Journal of Astrobiology
  • 2009
Abstract Gamma-ray bursts (GRBs) are likely to have made a number of significant impacts on the Earth during the last billion years. The gamma radiation from a burst within a few kiloparsecs wouldExpand
in the extragalactic shock model: 2. Revised ionization levels and their consequences
[1] It has been suggested that galactic shock asymmetry induced by our galaxy’s infall toward the Virgo Cluster may be a source of periodicity in cosmic ray exposure as the solar system oscillatesExpand
Climate change via CO2 drawdown from astrophysically initiated atmospheric ionization?
This investigated whether nitrate rainout resulting from the atmospheric ionization of enhanced cosmic ray flux could have, through its fertilizer effect, initiated carbon dioxide drawdown, which could possibly reduce the greenhouse effect and induce the climate change that led to the Pleistocene glaciations. Expand
It is shown that CR flux can vary by a factor of about 4.6 and reach a maximum at northernmost displacement of the Sun and the phase agreement between solar northward excursions and the diversity minima provides solid support for the model. Expand


Terrestrial Ozone Depletion Due to a Milky Way Gamma-Ray Burst
The first detailed computation of the effects of a gamma-ray burst in the Earth's atmosphere of one such impulsive event is performed, lending support to the hypothesis that a GRB may have initiated the late Ordovician mass extinction. Expand
Did a gamma-ray burst initiate the late Ordovician mass extinction?
A GRB could trigger the global cooling which occurs at the end of the Ordovician period that follows an interval of relatively warm climate, and some of the patterns of extinction and survivorship at this time may be attributable to elevated levels of UV radiation reaching the Earth. Expand
Terrestrial implications of cosmological gamma-ray burst models
The observation by the BATSE instrument on the Compton Gamma Ray Observatory that gamma-ray bursts (GRBs) are distributed isotropically around the Earth but nonuniformly in distance has led to theExpand
Crises and extinction in the fossil record; a role for ultraviolet radiation
A number of natural events can cause ozone depletion, including asteroid and comet impacts, large-scale volcanism involving the stratospheric injection of chlorine, and close cosmic events such asExpand
Effects of intense stratospheric ionisation events
High levels of ionising radiation in the Earth's stratosphere will lead to increased concentrations of nitrogen oxides and decreased concentrations of ozone. Changes in the surface environment willExpand
Astrophysical and Astrobiological Implications of Gamma-Ray Burst Properties
Combining results from Schmidt for the local cosmic rate and mean peak luminosity of γ-ray bursts (GRBs) with results on the history of the cosmic star formation rate (SFR), we provide estimates forExpand
Cosmic Rays from Gamma Ray Bursts in the Galaxy
The rate of terrestrial irradiation events by Galactic gamma-ray bursts (GRBs) is estimated using recent standard-energy results. We assume that GRBs accelerate high-energy cosmic rays, and weExpand
Gamma-Ray bursts: accumulating afterglow implications, progenitor clues, and prospects.
Advances in understanding how the GRB and afterglow radiation arises in terms of a relativistic fireball shock model have opened new vistas and questions on the nature of the central engine, the identity of their progenitors, the effects of the environment, and their possible gravitational wave, cosmic ray, and neutrino luminosity. Expand
Effect of solar proton events on the middle atmosphere during the past two solar cycles as computed using a two‐dimensional model
Daily average solar proton flux data for the years 1963-1984 (two solar cycles) have been used in a proton energy degradation scheme to derive ion pair production rates and, subsequently, HOx (H, OH,Expand
Geological Isotope Anomalies as Signatures of Nearby Supernovae
Nearby supernova explosions may cause geological isotope anomalies via the direct deposition of debris or by cosmic-ray spallation in the earth's atmosphere. We estimate the mass of materialExpand