Statistical characteristics of non-volcanic tremor distributions along the Mexican Subduction Zone

We analyze the statistical characteristics of non-volcanic tremor (NVT) sequences in the Mexican subduction zone. To this end, we employ various techniques, including the Gutenberg–Richter relationship, non-extensive statistics, and multifractal detrended moving-average analysis, to extract information on magnitude and interevent-time distributions. The b-value results reveal that b ranges from 1.25 to 2.42, with the highest values occurring in the down-dip portion of the plate interface. In contrast, the q-value shows an inverse behavior, reaching its highest values in the interplate coupling region. Similar to tectonic earthquakes, NVT sequences exhibit a multifractal structure in both magnitude and interevent-time series. The multifractality analysis suggests that this behavior is associated with long-term correlations, the probability distribution of the data, and nonlinear dynamics. Both apparent and intrinsic multifractality are identified, with the former being dominant. Our estimates of the Hurst exponent (H) range from 0.65 to 1.06; most sequences indicate strong persistence (H>0.95), while values exceeding unity suggest a transition toward non-stationary behavior. These high temporal correlations may reflect localized fluid-perturbed regions, although this interpretation remains speculative. Regarding the distribution that best describes interevent sequences, we find that most sequences are well described by a Lognormal distribution and, to a lesser extent, by a Gamma distribution. Finally, observations of tectonic tremor duration exhibit substantial scatter, resulting in low coefficients of determination in scaling relationships. The source of this variability may be related to the NVT generation mechanism or to detection and characterization processes.