Topics in EQW

Here you will find articles that will help add a few important pieces into the overall earthquake warning picture.

Modified Mercalli Intensity vs PGA/PGV
What is MMI?

The Modified Mercalli IntensityA qualitative scale of shaking intensity that uses observed effects to describe severity. The scale goes from MMI I (not felt) to MMI X+ (extreme damage). scale is used to describe the severity of ground shaking in an earthquake using observable effects.

Learn about MMI »
What are a few seconds good for?
What are a few seconds worth?

The warning time for a nearby earthquake may be short, but still quite useful.

See what a few seconds are worth »
Map showing locations of red tagged buildings from South Napa Ea
CC-Attribution-NonCommercial-ShareAlike 4.0/SWS
What is a Blind Zone?

The speed of an earthquake warning system determines whether it has a Blind ZoneA region, centered on the epicenter, where no warning is provided before serious ground motions arrive. A few seconds of delay producing a warning can produce a Blind Zone covering 400 square miles.. Speed isn't just about how long it takes to detect and analyze an earthquake. What really matters is how long it takes for protective actions to begin.

Explore why we're fastest »