Interepisodic Tremor and Slip Event Episodes of Quasi-spatiotemporally Discrete Tremor and Very Low Frequency Earthquakes in Cascadia Suggestive of a Connective Underlying, Heterogeneous Process

Exploring relationships between different types of slow earthquakes is essential for determining their source properties and controlling parameters. Studies show that very low frequency earthquakes (VLFEs) and tremor are discrete events that necessitate a further comprehensive study with respect to each other. Spatiotemporal analyses of VLFE and tremor catalogs from three interepisodic tremor and slip (inter-ETS) events in Cascadia show that seemingly uncorrelated events have more nuanced quasi-spatiotemporal relationships. Some of these events are either only related spatially, where tremor and VLFEs occur in the same location at different times, or related temporally, occurring at a distance but during the same time period. Including quasi-related events, nearly all VLFEs and tremor that do not exhibit immediate spatiotemporal relationships become correlated. I interpret this to mean they are related by a connective process that either is itself heterogenous or has heterogenous expressions based on other physical characteristics.