Tremor source location using time reversal: Selecting the appropriate imaging field

Studying triggered Non Volcanic Tremor (NVT) is important because it may help to map the depth of the locked zones of faults associated with high seismic risk. The success of this mapping depends on precisely locating the depth of tremor. Tremor, like other long‐lived signals (e.g., Earth hum) lacks distinct sharp timing features making it impossible to locate with classical approaches. Time Reversal has the advantage of exploiting the full waveform with no a priori assumption regarding the source or the observed signal. We perform a synthetic study of time reversal location of a long‐lasting source in the Los Angeles basin with a realistic 3D velocity model and sparse station set. We show that, the key to successfully locating NVT, is application of suitable imaging fields, such as the wave divergence, curl and energy current.