Hanford Site Seismic Monitoring provides an uninterrupted collection of high-quality raw seismic data from the Hanford Seismic Network located on and around the Hanford Site, and the Eastern Washington Regional Network. The seismic network on the Hanford Site consists of two types of equipment; seismometers and strong motion accelerometers. Seismometers are designed to locate earthquakes and determine the magnitude and hypocenter location. Strong motion accelerometers are designed to measure ground motion. The seismic network provides the capability to locate and identify sources of seismic activity and monitor changes in the historical pattern of seismic activity at the Hanford Site. The data collected is published and used by Hanford Site contractors involved in waste management, natural phenomena hazards assessments, and engineering design and construction. Seismic monitoring ensures compliance with CRD O 420.1B, Facility Safety and DOE Guide 420.1-1, Section 4.7, Emergency Preparedness and Emergency Communications. CRD O 420.1B establishes facility safety requirements related to nuclear safety design, criticality safety, fire protection and natural phenomena hazards mitigation. For earthquake monitoring, the order requires that facilities or sites with hazardous materials shall have instrumentation or other means to detect and record the occurrence and severity of seismic events.