Validation of seismic hazard curves using a calibrated 14 ka lacustrine record in the Eastern Alps, Austria.

Seismic hazard maps are crucial for earthquake mitigation and mostly rely on probabilistic seismic hazard analysis (PSHA). However, the practise and value of PSHA are under debate because objective testing procedures for seismic hazard maps are scarce. We present a lacustrine turbidite record revealing 44 earthquakes over the last ~ 14 ka and use it to test seismic hazard curves in southern Austria. We derive local seismic intensities for paleo-earthquakes by applying scaling relationships between the sedimentary imprint and seismic intensity of well-documented historical earthquakes. The last ~ 2.8 ka of the record agree with a Poissonian recurrence behaviour and therefore a constant hazard rate, which is the modelling choice for standard PSHA. The lacustrine data are consistent with the intensity-frequency relationship of the local seismic hazard curve, confirming the current PSHA approach for this part of Austria. On longer timescales, distinct phases of enhanced regional seismicity occurred, indicating a potential increase of seismic hazard after large earthquakes-a factor hitherto disregarded in the PSHA of the Eastern Alps. Our new method forms an independent procedure to test hazard maps in any setting where suitable lake systems are available.

Rapid assessment of heavy metal pollution using ion-exchange resin sachets and micro-XRF core-scanning.

Conventional pollution monitoring strategies for heavy metals are often costly and unpractical. Innovative sampling and analytical approaches are therefore needed to efficiently monitor large areas. This study presents a novel, simple, fast, and inexpensive method to monitor heavy metal pollution that uses cation-exchange resin sachets and the micro-XRF core-scanning technique (XRF-CS). The resin passive samplers act as concentrators of cationic species and can be readily deployed spatially and temporally to record pollution signals. The large number of analytical tasks are then overcome by the fast and non-destructive XRF-CS to precisely assess elemental concentrations. Quantifying element loading involves direct comparison with a set of identically prepared and scanned resin reference standards containing Ca, Ti, Cr, Mn, Ni, Cu, Zn, Pb. The results show that within the test range (from 0-1000 s mg kg-1), the calibration lines have excellent regressions (R2 ≥ 0.97), even at the shortest exposure time (1 s). A pilot field survey of a suspected polluted area in central Taiwan, where 30 resin sachets had been deployed, identified a pollution hot spot in a rapid and economical manner. Therefore, this approach has the potential to become a valuable tool in environmental monitoring and forensics.