The seasonal, latitudinal, and diurnal distributions of whistler-induced electron precipitation events, detected as subionospheric signal perturbations (Trimpi events), have been studied by means of data sets acquired in 1982--1983 at Palmer and Siple stations, Antarctica. The data sets, substantially larger than any previously examined, confirm previous indications of a broad (~4 hour) maximum in hourly event occurrence rates. The peak was centered ~ 1--2 hours after local midnight at Palmer for the roughly north-south Argentina Omega 12.9--kHz path, but was shifted several hours later for the 23.4-kHz NPM path, which has a westerly arrival bearing at Palmer. The previously reported seasonal variation, with peaks at the equinoxes, was confirmed; activity persisted in the austral winter, particularly following a magnetic storm, but in general occurred on fewer days and during shorter daily periods. Comparisons of occurrence data at Siple (L≂4.3) and Palmer (L≂2.4) for particular signal sources showed the number of days of activity to be larger at Palmer by a factor of ~ 2 or more. Comparisons of five months of simultaneous almer and Siple receptions of 21.4-kHz NSS signals on north-south paths suggest that most of the events observed at Siple occurred as the result of ionospheric perturbations relatively close to the L shell of Palmer, that is, in the range L=2-3. This result is consistent with the expected variation with latitude of the energy of electrons precipitated due to equatorial gyroresonance at typical whistler frequencies. ¿American Geophysical Union 1987