ShakeMap modelling for the 1568 Shaanxi Gaoling Earthquake, China

Abstract Scenarios of earthquakes play an important role in planning and coordinating emergency response, seismic risk management, and identifying exposure of structures, lifelines, and utilities. We describe the calculation of distributions of ground shaking that might be generated if the 1568 Shaanxi Gaoling M∼7 earthquake were to recur. In order to adjust the Ground Motion Prediction Equations (GMPEs) for the local conditions, we use the ShakeMap software to calculate a scenario of the nearby 1556 Huaxian M8¼ earthquake, for which the distribution of isoseismals is constrained by historical records. We use the ASK13 GMPEs, and find that, by augmenting the resulting ground shaking by 50% of its standard deviation, we can satisfactorily reproduce the historical observations. This scheme is then applied to the calculation of a scenario ShakeMap Scenario for the 1568 Shaanxi Gaoling M6¾ earthquake. The rupture parameters of the seismogenic faults for each of these scenarios are determined from field observations. The macroscopic seismic site conditions for this area are calculated from the topographic gradient Vs30 model of Wald and Allen [1]. The resultant scenario ShakeMap provides the basis for the calculations of seismic hazard and risk for Weinan city and its surroundings, which are described elsewhere in this issue.