Tectonic Hotspots: the Week's Most Powerful Earthquakes Ranked

## Frequently Asked Questions

Where does the earthquake data come from? All events are drawn from the USGS Earthquake Hazards Program feed, which publishes global seismic events in near real time.

Why rank by magnitude? Magnitude is the most consistent cross-region measure of an earthquake's energy release and is reported for every event above magnitude 4.5 worldwide.

Why do so many events cluster in the same regions? The Ring of Fire, the Alpine-Himalayan belt, and the mid-ocean ridges concentrate ~90% of global seismic energy because that is where tectonic plates meet, subduct, or slide past each other.

Do these events include aftershocks? Yes. When an aftershock falls within the top ten magnitudes of the week, it is included and labeled as an aftershock in its entry.

How are these earthquakes ranked?

By raw moment magnitude as reported in the USGS real-time earthquake feed for the seven days preceding publication. Larger magnitude means more energy released at the source.

Why do so many of the week's strongest quakes cluster along the Pacific?

Most of the events on this list sit on the Pacific Ring of Fire, the belt of subduction zones and transform faults that rings the Pacific Ocean. Subduction zones — where one tectonic plate dives beneath another — produce the largest earthquakes on Earth.

What does 'M 6.3' mean?

'M' stands for moment magnitude, the modern scale used for earthquakes above roughly magnitude 3.5. Each whole-number increase represents about 32 times more energy released.

Is a magnitude 5.5 earthquake dangerous?

In a populated area with vulnerable buildings, yes — a magnitude 5.5 can cause significant damage. At sea, as with several events on this list, it typically produces only small, locally felt shaking.

Where can I verify these events?

Every entry links to the corresponding USGS event page with origin time, depth, and reviewed coordinates.