2020 Update to the Quaternary Fault and Fold Database for Washington State

This release is an update to the online "Quaternary fault and fold database" for Washington State. The online database was last updated for Washington in 2014 – this 2020 update includes newly identified and modified traces and geometries for on-shore faults gleaned from new peer-reviewed studies and mapping of active faults within the state of Washington. These data contain lines representing the location of faults with known or suspected Quaternary (less than 1,600,000 yrs) activity in the state of Washington. This data was compiled in conjunction with the Washington State Geological Survey. Faults are attributed following the Quaternary fault and fold database attributes, including information such as age, slip sense, dip direction, class, and mapped scale. Significant modifications include: 1) newly mapped active traces of the Sadie Creek fault, Entiat fault system, Spencer Canyon fault system; 2) modified geometry of the Seattle fault zone; and 3) representative lines for the areas of the Mount Saint Helens seismic zone, Western Rainier seismic zone, and Goat Rocks seismic zone.