Seismic waves excited by human activity frequently obscure signals
due to tectonic processes and are discarded as a nuisance. Seismic
noise-field analysis is, however, a powerful tool for characterizing
anthropogenic activities. In this talk, I will briefly review the
seismological fingerprints of anthropogenic noise sources and then
present a scheme devised to identify precursory activity leading to the
October 7 terrorist attack. The precursory activity in Gaza included
massive mobilization, documented by multiple media outlets. Favorable
conditions arose due to a temporary lack of anthropogenic activity in
Israel, allowing remote seismic stations to record signals due to Gaza
vehicle traffic in the early hours of Oct. 7. Seismogram analysis reveals
a widespread signal that abruptly emerged above the nighttime noise
levels about 20 minutes before the attack began. Statistical analysis
suggests the signal is highly anomalous; tests for significance indicate
that pre-attack inter-station correlations would emerge by chance only
once every 18,000 years. Tripartite array analysis was used to detect
surface waves, locate their sources, and demarcate the extent of preattack
activity within the Gaza Strip. The signal’s amplitude, frequency,
and spatiotemporal distribution appear to be aligned with vehicular
traffic emanating from the south-central region of the Gaza Strip and
extending towards its peripheries in the half-hour window preceding the
invasion. This provides valuable tactical information and suggests
embedding seismic noise-field analysis into decision-making protocols
could enhance preparedness for terrorist attacks.