Meteorite mass distributions and differences between Antarctic and non-Antarctic meteorites

Meteorite mass distributions provide important insight into real and apparent differences between Antarctic and non-Antarctic meteorites. Antarctic meteorites are typically smaller than non-Antarctic meteorites and represent a different portion of the mass distribution of infalling meteorites. This results from the different methods employed to acquire the collections and from the much smaller effective collecting area for Antarctic meteorites. Comparisons of the proportions and mass distributions of H and L chondrites for different ice fields suggest that previously reported high H to L ratio among Antarctic meteorites compared to witnessed falls results from an unrecognized H5 shower fall that covered the Allan Hills Main and Near Western ice fields in the relatively recent past. The probable presence of unrecognized shower falls among the Antarctic meteorites means that population statistics, even corrected for presently recognized pairing, cannot be used to support the suggestion by Dennison et al. (1986) of a temporal variation in the mixture of meteorites arriving on earth.