  Fireballs are infrequently recorded by seismic sensors on the ground. If
recorded, they are usually reported as one-off events. This study is the first
seismic bulk analysis of the largest single fireball data set, observed by the
Desert Fireball Network (DFN) in Australia in the period 2014-2019. The DFN
typically observes fireballs from cm-m scale impactors. We identified 25
fireballs in seismic time series data recorded by the Australian National
Seismograph Network (ANSN). This corresponds to 1.8% of surveyed fireballs, at
the kinetic energy range of 10$^6$ to 10$^{10}$ J. The peaks observed in the
seismic time series data were consistent with calculated arrival times of the
direct airwave or ground-coupled Rayleigh wave caused by shock waves by the
fireball in the atmosphere (either due to fragmentation or the passage of the
Mach cone). Our work suggests that identification of fireball events in the
seismic time series data depends both on physical properties of a fireball
(such as fireball energy and entry angle in the atmosphere) and the sensitivity
of a seismic instrument. This work suggests that fireballs are likely
detectable within 200 km direct air distance between a fireball and seismic
station, for sensors used in the ANSN. If each DFN observatory had been
accompanied by a seismic sensor of similar sensitivity, 50% of surveyed
fireballs could have been detected. These statistics justify the future
consideration of expanding the DFN camera network into the seismic domain.
