A ∼62 My periodicity in fossil biodiversity has been observed in independent studies of paleontology databases over ∼0.5Gy. The period and phase of this biodiversity cycle coincides with the oscillation of our solar system normal to the galactic disk with an amplitude ∼70 parsecs and a period ∼64 My. Our Galaxy is falling toward the Virgo cluster, forming a galactic shock at the north end of our galaxy due to this motion, capable of accelerating particles and exposing our galaxy's northern side to a higher flux of cosmic rays. These high-energy particles strike the Earth's atmosphere initiating extensive air showers, ionizing the atmosphere by producing charged secondary particles. Secondary particles such as muons produced as a result of nuclear interactions are able to reach the ground and enhance the biological radiation dose. Using a Monte Carlo simulation package CORSIKA, we compute the biological dose resulting from enhanced muon exposure from cosmic rays and discuss their implications for terrestrial biodiversity variations.
ASJC Scopus subject areas
- General Earth and Planetary Sciences