Suspected Reflections of Vertical Deformation to Moderate Earthquake in the Capital Region

Crust vertical deformation and its characteristics in the past three decades is analyzed in accordance with precise re-leveling data (1983-2014) in the Chinese capital region, and the vertical deformation characteristics in this area before and after three M_S>4.0 earthquakes are presented. The results show that the inheritance motion is dominant in the deformation field, which means there are uplift in the northwest (mountain zone) and subsidence in the southeast (basin and plain zone), as well as partial vertical fluctuations in such background. The results also show that vertical deformation anomalies appeared about 150 km near the epicenter and 5-7 years before the M_S>4.0 earthquakes, and then anomalies disappeared before the earthquakes. It may mean that in this region middle strong earthquake may occur during a relatively quiet period after a period of perceivable crustal movement.