READING THE NUMBERS
63 km ENE of Pedro Bay, Alaska
Magnitude describes the source. Intensity describes what a place experienced.
← Back to this reportShaking at a place
No shaking intensity has been published for this report yet.
MAGNITUDE · SOURCE SIZE
M-0.4
Each one-unit increase represents about 32 times the energy released. Magnitude alone does not tell you how strongly a particular place shook.
DEPTH · BELOW THE EPICENTER
1.0 km · shallow
The epicenter is the surface point above the source. Shallow: under 70 km. Intermediate: 70–300 km. Deep: over 300 km.
Why local ground can change the shaking
SAME QUAKE. DIFFERENT GROUND.
Why nearby places
can feel it differently.
M-0.4 describes the source. The ground under each location can change the shaking that arrives. Try changing one site below.
Illustrative ground motion, not measured conditions or building damage at this earthquake. Soft ground does not amplify every wave equally.