Rupture directivity is a seismic source property reflecting the dynamics of the rupture process. When ruptures exhibit a clear sense of direction, they generate asymmetric radiation patterns in seismic amplitudes and corner frequencies, an effect first described analytically by Ben-Menahem (1961) as a moving point-source. Subsequent numerical studies (Kurzon et al., 2019, 2021) demonstrated that incorporating source-volume, damage, and rheological complexity, significantly improves the representation of rupture processes, and that in many cases P-wave radiation patterns are more stable and indicative of rupture directivity than S-waves.
Here, we examine these numeric insights against field observations using a unique dataset of 31 earthquakes (Mw 2.5–4.5) from a seismic swarm in the Sea of Galilee. The events were recorded by ~30 stations with good azimuthal coverage, enabling robust assessment of rupture directivity and rupture properties. Our results show that (1) most events exhibit clear rupture directivity; (2) P-waves display stronger and more consistent directivity than S-waves, in agreement with numerical simulations; (3) S-waves generally show weaker directivity, but agree with P-waves inferred signatures; and (4) rupture propagation is predominantly toward the SE–SSE, compatible with an east-trending oblique fault. In addition, by quantifying the directivity strength from the radiation patterns, we may estimate rupture velocities as Vr/Vs = 0.65–0.95; S to P energy ratio as ~5–15; and S-wave energy loss of ~20–60% during rupture. Our results validate the numerical simulations and demonstrate the ability to infer dynamic rupture properties for small earthquakes.