Supernova triggers for end-Devonian extinctions

Fields, Brian D.; Melott, Adrian L.; Ellis, John; Ertel, Adrienne F.; Fry, Brian J.; Lieberman, Bruce S.; Liu, Zhenghai; Miller, Jesse A.; Thomas, Brian C.

doi:10.1073/pnas.2013774117

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Journal article

Supernova triggers for end-Devonian extinctions

2020-8-18

Published in:

Proceedings of the National Academy of Sciences. - Proceedings of the National Academy of Sciences. - 2020, vol. 117, no. 35, p. 21008-21010

Multidisciplinary

English The Late Devonian was a protracted period of low speciation resulting in biodiversity decline, culminating in extinction events near the Devonian–Carboniferous boundary. Recent evidence indicates that the final extinction event may have coincided with a dramatic drop in stratospheric ozone, possibly due to a global temperature rise. Here we study an alternative possible cause for the postulated ozone drop: a nearby supernova explosion that could inflict damage by accelerating cosmic rays that can deliver ionizing radiation for up to∼100ky. We therefore propose that the end-Devonian extinctions were triggered by supernova explosions at∼20 pc, somewhat beyond the “kill distance” that would have precipitated a full mass extinction. Such nearby supernovae are likely due to core collapses of massive stars; these are concentrated in the thin Galactic disk where the Sun resides. Detecting either of the long-lived radioisotopesSm146orPu244in one or more end-Devonian extinction strata would confirm a supernova origin, point to the core-collapse explosion of a massive star, and probe supernova nucleosynthesis. Other possible tests of the supernova hypothesis are discussed.

Language

English

Open access status

hybrid

Identifiers

DOI 10.1073/pnas.2013774117
ISSN 0027-8424

Persistent URL

https://folia.unifr.ch/global/documents/203933

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