Tokyo, Japan – A catastrophic 9.1-magnitude earthquake struck off the northeast coast of Japan early Tuesday morning, triggering a powerful tsunami and plunging much of the nation into a state of emergency.

Experts are calling it the most powerful seismic event in over a century, with widespread infrastructure damage, disruptions in basic services, and a nationwide call for international assistance.

The earthquake’s epicenter was located near Miyagi Prefecture, roughly 130 kilometers off the coast. Shaking was felt as far away as Tokyo, over 300 kilometers from the origin point. Seismic sensors across the nation were triggered, sounding alarms that gave many citizens precious seconds to seek shelter.

According to the Japan Meteorological Agency (JMA), the quake lasted more than one minute and released energy on a scale rarely seen in recorded history. Modern seismic records show this to be the strongest earthquake in Japan since such measurements began.