Lacustrine Records of Past Seismic Shaking
摘要
Reliable seismic hazard analysis builds upon a robust reconstruction of spatiotemporal rupture variability over multi-millennial timescales. Lacustrine sediment sequences can provide long and complete records of strong seismic shaking due to the generally continuous nature of subaqueous sedimentation, allowing for high record sensitivity, continuity and accurate age control. Seismic shaking, which can originate from different seismic sources in a region, is typically recorded as in-situ deformation structures or deposits resulting from subaqueous mass-wasting, lake water oscillations or earthquake-related processes in the catchment of the lake. Several calibration methods have been developed to relate the type and size of lacustrine sedimentary earthquake imprints to ground shaking parameters for recent events. By integrating multi-lake records with other paleoseismic archives, this quantitative information enabled evaluation of the possible location, extent and magnitude of prehistoric earthquakes. This chapter introduces the principles of quantitative lacustrine paleoseismology and illustrates its value by three comprehensive case studies from intraplate, transform and subduction zone settings.