9 minutes in between
>7.8
>6.7
Richter Earthquake
Magnitudes Effects
Less than 3.5 Generally not felt, but recorded.
3.5-5.4 Often felt, but rarely causes damage.
Under 6.0 At most slight damage to well-designed buildings.
Can cause major damage to poorly constructed buildings
over small regions.
6.1-6.9 Can be destructive in areas up to about 100 kilometers
across where people live.
7.0-7.9 Major earthquake. Can cause serious damage over larger areas.
8 or greater Great earthquake. Can cause serious damage in areas several
hundred kilometers across.
https://www.ux1.eiu.edu/~cfjps/1300/magnitude.html