The above map shows the potential for ground shaking across the city of Seattle, WA. The surface wave frequency being mapped is 1 cycle per second (the frequency most dangerous to buildings of 10 stories and taller) with a 10% probability of exceedence (statistical metric describing the probability that a particular value will be met or exceeded) within the next 50 years. Essentially, the map shows where the shaking is going to be felt strongest in the event of an earthquake in Seattle.
Curious about a particular area? Click any of the color coded zones to learn it's shaking potential!
Seattle is host to two kinds of fault; reverse and thrust. Most of the faults are thrust type faults, see if you can guess which one is the reverse fault! You can find out what type of fault each one is by clicking on the dashed line. Thrust faults and reverse faults both move in the dip-slip type of motion, meaning these faults move vertically, just at different angles. Thrust faults move at less than 45 degrees and reverse faults move at an angle greater than 45 degrees.