  Deschamps and Mottez (hereafter DM) argue that the Gauss-Matuyama terrestrial
magnetic field reversal may have left a vanishing main dipole moment to the
field for a time of order 10,000 years. They say this may have allowed an
enhanced cosmic ray flux, boosting the effect we proposed in Melott and Thomas
(2019). We point out that the bulk of the cosmic ray flux from a nearby
supernova should be too energetic, up to a million times more energetic than
the limits of deflection by the terrestrial magnetic field. In fact, only those
highly energetic ones will directly reach the troposphere, relevant for
cloud-to-ground lightning. From Cosmic Explosions to Terrestrial Fires?: A
Discussion. F. Deschamps and F. Mottez. J. Geology 128, online ahead of print.
(2020) From Cosmic Explosions to Terrestrial Fires?: A Reply A.L. Melott and
B.C. Thomas. J. Geology 128, online ahead of print. (2020) From cosmic
explosions to terrestrial fires? (A.L. Melott and B.C. Thomas) Journal of
Geology, 127, 475-481 10.1086/703418 (2019) [arXiv:1903.01501]
