JPL

Map of NASA-JPL campus in Pasadena, CA showing locations of CSN accelerometer deployments. Horizontal dimensions are approximately 1 km by 1 km.

Our NASA-JPL partner comprises a 1 km x 1 km campus representing a mini-city prototype "sandbox" in which to operate our ground-building network, and to test the integrated city-scale 4D monitoring network through refinement of algorithms. It serves as our well-instrumented mini-city testbed because one or multiple CSN accelerometers are installed at each of the approximately 100 buildings on the JPL campus. The campus is home to a variety of building types. Of the total 220 stations deployed at JPL, 100 are ground-level stations contributing maximum shaking pick data to the experimental ShakeMap. The remaining 120 stations are deployed on upper floors of buildings that have up to 9 floors.

JPL sits at the southern foothills of the San Gabriel Mountains, and next to faults north of campus. Microzonation - the mapping of variations in seismic response amplification of the ground occurs - over the JPL campus as shown by local earthquakes recorded by the CSN sensors distributed around campus. For example, the 7/25/2015 M4.2 Fontana earthquake indicated amplification at JPL sites adjacent to the foothills. These sites may have experienced a basin-edge effect in which the geometry and impedance contrast between the sedimentary basin to the south and hard rock mountains to the north, affected the campus response on a length scale of 10-100 meters.

JPL building types include wood frame, reinforced concrete, steel-moment frame, steel sheds and modular trailers. Each of these structures has a canonical fragility curve associated with it based on a building classification supplied by FEMA's natural hazard analysis HAZUS software. A web instance of the CSN-fragility analysis has been constructed for a 9-story building on campus.

NASA-JPL CSN-Fragility instance showing assessed fragilities in select buildings due to a scenario M6.9 Verdugo fault earthquake near the JPL campus.