Stopping phase reveals abrupt arrest of large strike-slip earthquakes
Summary
Earthquake magnitude is controlled by where and when rupture propagation stops. Yet rupture arrest has rarely been directly observed in near-field seismic records of natural earthquakes. Here we present systematic near-field observations of ground-motion stopping phases from large strike-slip earthquakes. Analysis of 12 global events shows that transient overshoot in fault-parallel ground surface displacement is a robust diagnostic signature of abrupt termination of rupture propagation. Dy
Content
# Stopping phase reveals abrupt arrest of large strike-slip earthquakes
*Published: 2026 Apr 23*
Earthquake magnitude is controlled by where and when rupture propagation stops.
Yet rupture arrest has rarely been directly observed in near-field seismic
records of natural earthquakes. Here we present systematic near-field
observations of ground-motion stopping phases from large strike-slip
earthquakes. Analysis of 12 global events shows that transient overshoot in
fault-parallel ground surface displacement is a robust diagnostic signature of
abrupt termination of rupture propagation. Dynamic rupture simulations reveal
that near-field ground motions are strongly amplified by low wavespeed rocks at
shallow depth, which enhance the amplitude of displacement overshoot recorded at
the surface. The occurrence of stopping phases at near-fault locations far from
mapped rupture termini implies that large strike-slip earthquakes rupture in a
segmented manner, with dynamic rupture propagation punctuated by abrupt arrest
and reinitiation at internal fault-segment boundaries.
DOI: 10.1126/science.aef3733