Ground Motion Duration Patterns for Vrancea (Romania) Intermediate-Depth Earthquakes

This study is focused on evaluating ground motion durations of Vrancea intermediate-depth earthquakes in Romania, the context future updates to Romanian seismic design code P100-1/2013. The database compiled for this consists about 200 motions recorded during five moderate and large that occurred period 1977–2004 had moment magnitudes MW ≥ 6.0. Two empirical models were derived significant duration considering two time intervals (5–75% 5–95%) accumulation Arias Intensity IA. An analysis data shows mean ratio between D5-95 D5-75 2.8. Moreover, regression also largest share variability due within-event component (site term). Among coefficients, hypocentral distance soil conditions appear have a larger impact compared earthquake magnitude. It was observed median predicted using model proposed much smaller than ones from Eurocode 8 draft same magnitude range. Finally, geographic trends related distribution residuals evaluated three with number available recordings.