Multiple shallow, active fault lines traverse the Portland metropolitan area. Among them are the Portland Hills Fault on the city's west side, and the East Bank Fault on the east side. According to a 2017 survey, several of these faults were characterized as "probably more of a hazard" than the Cascadia subduction zone due to their proximities to population centers, with the potential of producing magnitude 7 earthquakes. Notable earthquakes that have impacted the Portland area in recent history include the 6.8-magnitude Nisqually earthquake in 2001, and a 5.6-magnitude earthquake that struck on March 25, 1993.