Overview
- A paper published in Science on September 17, 2026, reports that researchers using seismic records from South Korea and China detected roughly 1,399 local earthquakes around Mount Mantap from 2008 through 2025, with rates and sizes rising after the Sept. 3, 2017 detonation.
- High‑precision locations show the events cluster along two roughly north‑northwest fault zones about 24 kilometers long and occur at unusually shallow depths, often less than 1 km below the surface.
- Authors argue repeated underground tests progressively damaged and fractured the shallow crust beneath Mantap, changing local stress conditions and allowing long‑dormant intraplate faults to reactivate over years.
- The study relied on matched‑filter analysis of distant seismic stations and satellite measurements of summit collapse and deformation and had no on‑site North Korean data, a limitation the authors note for interpreting causes and hazards.
- Researchers warn the persistent, delayed seismicity complicates long‑term monitoring and attribution of future underground tests, could raise local hazard if larger fault sections fail, and shows how anthropogenic activity can leave a lasting seismic footprint.