Seismicity Clustering and Statistical Modeling of the Intermediate-Depth Earthquakes in the Weber Deep, Banda Arc

We analyzed seismicity clustering and source mechanisms of intermediate-depth earthquakes in the Weber Deep, Banda Arc, with a focus on the 2023 M_w 7.6 Tanimbar event. Using joint Bayesian moment tensor inversion and nearest-neighbor clustering in the space-time-depth-magnitude (STDM) domain, we identified a thrust faulting source mechanism-oriented NW-SE at a depth of 108 ± 3 km, dominated by a double-couple component (92%). Centroid position was shifted 6 km south and 8 km east, with uncertainties estimated at ± 3 km. Seismicity from 2019 to 2023 exhibited a unimodal clustering pattern, indicating a single dominant seismogenic process, consistent with the uniform geometry of the Indo-Australian slab subducting beneath the Banda Arc. The time interval between events contributed most to clustering (45.83%), highlighting temporal controls on seismicity. The findings refine understanding of slab deformation beneath the Banda Arc and provide implications for seismic hazard, supporting infrastructure resilience and disaster planning in eastern Indonesia. The STDM framework, combined with full-waveform inversion, demonstrates robust applicability for tectonic and hazard studies in complex subduction environments.