Cataclysmic astrophysical events such as black hole mergers could release energy in unexpected forms. Exotic low-mass fields (ELFs), for example, could propagate through space and cause feeble signals detectable with quantum sensor networks such as the atomic clocks of the GPS network or the magnetometers of the GNOME network. These results are particularly interesting in the context of the search for dark matter, as low-mass fields are regarded as promising candidates for this exotic form of matter.