Abstract
Detecting a seismic event from Europa’s silicate interior would provide
information about the geologic and tectonic setting of the moon’s rocky
interior. Reflections off a metallic core would indicate the presence,
size, and state of the hypothesized core. However, the subsurface ocean
will attenuate the signal, possibly preventing the waveforms from being
detected by a surface seismometer. Here, we investigate the minimum
magnitude of a detectable event originating from Europa’s silicate
interior. We analyze likely signal-to-noise ratios and compare the
predicted signal strengths to current instrument sensitivities. We show
that a magnitude M_w >3.5 would be sufficient to overcome
the predicted background noise. However, a minimum magnitude of M_w
> 5.5 would be required for current instrumentation to be
able detect the event. A thinner ice shell transmits greater ground
acceleration amplitudes than a thicker ice shell, which might allow for
M_w > 4.5 to be detectable.