Marine paleoseismology from Very High Resolution seismic imaging: the Gondola Fault Zone (Adriatic foreland)

Abstract

We present a marine paleoseismology analysis of a dense network of very high resolution seismic profiles along the Gondola Fault Zone (GFZ), a right-lateral, E-W–striking, active fault system in the Adriatic foreland. This case-study aims to show how time and space variations in the activity of a dominantly right-lateral fault system can be assessed based on the vertical component of slip alone. The GFZ has been investigated for a length of 50 km. It includes two parallel subvertical fault sets and two main anticlines. The distribution of the late Middle Pleistocene to Holocene vertical component of displacement along-fault is bell-shaped, suggesting that in the long-term the fault zone acts as a single, kinematically coherent structure. Slip rates on individual fault segments, however, suggest that they may rupture independently. Vertical slip rates calculated for late Middle Pleistocene-Holocene intervals fall in a narrow range and are consistently small (0-0.18 mm/a).