ABSTRACT. We present routine methods of target preparation for radiocarbon analysis at the ANTARES Accelerator Mass Spectrometry (AMS) Centre, as well as recent developments which have decreased our procedural blank level and improved our ability to process small samples containing less than 200 µg of carbon. Routine methods of 14 C sample preparation include sample pretreatment, CO 2 extraction (combustion, hydrolysis and water stripping) and conversion to graphite (graphitization). A new method of cleaning glassware and reagents used in sample processing, by baking them under a stream of oxygen, is described. The results show significant improvements in our procedural blanks. In addition, a new graphitization system dedicated to small samples, using H 2 /Fe reduction of CO 2 , has been commissioned. The technical details of this system, the graphite yield and the level of fractionation of the targets are discussed.

Large earthquakes in mountain regions commonly trigger extensive landsliding and are important drivers of erosion, but the contribution of this landsliding to long-term erosion rates and seismic hazard remains poorly understood. Here we show that lake sediments record postseismic landscape response as a sequence of turbidites that can be used to quantify erosion related to large (moment magnitude, M w > 7.6) earthquakes on the Alpine fault, New Zealand. Alpine fault earthquakes caused a threefold increase in sediment fl ux over the ~50 yr duration of each postseismic landscape response; this represents considerable delayed hazard following earthquake-induced strong ground motion. Earthquakes were responsible for 27% of the sediment fl ux from the lake catchment over the past 1100 yr, leading us to conclude that Alpine fault earthquakes are one of the most important drivers of erosion in the range front of the Southern Alps.

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