- A new study reveals that minutes after the 2011 magnitude 9 Tohoku-Oki earthquake and tsunami, a previously unrecognised phenomenon may have caused the whole of Japan to shift further eastwards.
- Researchers re-examined satellite data and found that seismic shear waves travelled through the Earth, bounced off the planet's core, and returned to the surface, reactivating tectonic plate boundaries.
- This triggered a multiplate-interface slip event, causing Japan to shift by approximately 5-6mm, an amount of ground movement common after large earthquakes but notable for its widespread impact.
- The triggered slip had the broadest rupture area of any single event yet documented, spanning a length similar to mainland Japan and exceeding the mainshock rupture length by 6-7 times.
- Scientists highlight this as a previously unknown type of seismic hazard, suggesting that significant ground motion can occur many minutes after an earthquake's main shaking has passed.
IN FULL
