Many parts of eastern Japan experienced unusually long and slow shakes after Aomori Prefecture was hit by a strong earthquake. Here's what you need to know about “long-period ground motion.” https://www.japantimes.co.jp/news/2025/12/09/japan/science-health/japan-quake-long-period-ground-motion/?utm_medium=Social&utm_source=mastodon #japan #sciencehealth #earthquakes #geology #ishikawa