We model fluid pressure diffusion in a channel along the subduction interface in which the permeability varies through a valving mechanism• Tremor is generated as valves break open and interactions between valves through fluid pressure transients shape realistic event patterns• The input fluid flux in the fault controls seismic activity, opening possibilities to diagnose hydraulic conditions using LFE patterns

Low‐frequency earthquakes (LFEs) are detected within tremor, as small, repetitive, impulsive low‐frequency (1–8 Hz) signals. While the mechanism causing this depletion of the high‐frequency content of their signal is still debated, this feature may indicate that the source processes at the origin of LFEs are different from those for regular earthquakes. Key constraints on the LFE‐generating physical mechanisms can be obtained by establishing scaling laws between their seismic moment and source durations. Here we apply a simple spectral analysis method to the S waveforms of LFEs from Guerrero, Mexico, to measure their seismic moments and corner frequencies, a proxy to source duration. We find characteristic values of M0∼3×1012 N.m (Mw∼2.3) and fc∼3.0 Hz with the corner frequency very weakly dependent on the seismic moment. This moment‐duration scaling observed for Mexican LFEs is similar to one previously reported in Cascadia and is very different from the established one for regular earthquakes. This suggests that they could be generated by sources of nearly constant size with strongly varying intensities. LFEs do not exhibit the self‐similarity characteristic of regular earthquakes, suggesting that the physical mechanisms at their origin could be intrinsically different.

The occurrence and the style of volcanic eruptions are largely controlled by the ways in which magma is stored and transported from the mantle to the surface through the crust. Nevertheless, our understanding of the deep roots of volcano-magmatic systems remains very limited. Here, we use the sources of seismovolcanic tremor to delineate the active part of the magmatic system beneath the Klyuchevskoy Volcanic Group in Kamchatka, Russia. The tremor sources are distributed in a wide spatial region over the whole range of crustal depths connecting different volcanoes of the group. The tremor activity is characterized by rapid vertical and lateral migrations explained by fast pressure transients and dynamic permeability. Our results support the conceptual model of extended and highly dynamic trans-crustal magmatic systems.