Higher-energy PNSN tremor starts had fewer 20 or 60 km depth labels in matched groups at 40-50 N in 2017-2025

We tested depth labels in a fixed PNSN tremor catalog at 40-50 N in 2017-2025. Of 456,452 starts, 50.28% had labels at 20 or 60 km. Within 9,094 groups matched by date, latitude band and duration label, the higher-energy half had 4.37 percentage points fewer endpoint labels. The conditional 95% interval from 30-day blocks was -4.83 to -3.91 points. Longitude matching and duplicate removal gave similar results. The separate endpoints differed: the higher-energy half had fewer 20 km labels but more 60 km labels. This is a catalog association, not a test of true source depth or a causal mechanism. Prior work already warns that envelope depth estimates are unreliable. Coarse spatial matching, shared waveform errors, overlapping windows and one snapshot limit inference. The package gives retained rows, source hashes, code, tables, block draws, a figure and independent arithmetic checks.

Cascadia · tectonic tremor · depth labels · energy · catalog audit · matched comparison