Distant M5.5 event counts gave no clear depth contrast after isolated M7 to below 8 earthquakes in 2001-2024

We compared M5.5 or larger earthquake counts after and before isolated M7 to below 8 earthquakes in 2001-2024. The main ring was 500 to below 1500 km and the time gap was 1 to below 7 days. A symmetric 30-day isolation rule retained 190 shallow and 25 deep centers. After adjustment for two magnitude bins, the excess was 0.116 events per shallow center and 0.105 per deep center. The deep-minus-shallow difference was -0.011, with a conditional 95% three-year block interval of -0.207 to 0.191. Both individual intervals included zero. A local 200 km comparison showed a strong shallow excess. A distant shallow excess without isolation did not remain clear with longer isolation. The test gives no clear distant depth contrast and does not show equal rates or an absence of triggering. Sparse deep counts, selection, regional dependence, mixed magnitudes and one catalog limit inference. The package gives new code, aggregate evidence, bootstrap values, audits, source hashes and an external retrieval recipe.

deep earthquakes · remote seismicity · ComCat · temporal asymmetry · mainshock selection · null result