Over 5 years of continuous broad-band seismic record of the earth vibrations generated by the Aragón River, Central Pyrenees.

In recent years the analysis of background seismic noise variations in the proximity of river channels has revealed as a useful tool to monitor river flow, even for modest discharges. Nevertheless, this monitoring is usually carried on using temporal deployments of seismic stations. The LC.CANF seismic broad-band station, acquiring data continuously since 2011 and located inside an old railway tunnel in the Central Pyrenees, at about 400 m of the Aragón River channel, provides an excellent opportunity to enlarge this view as it offers a long term monitoring of a mountain river. Data from this site, located at higher distance from the river channel than is most of fluvial seismology experiments, can provide additional clues on the discrimination between vibrations related to turbulent water flow and and those generated by bedload transport. Up to now, two large rainfall events resulting in large discharge and damaging floods have been recorded, both sharing similar properties and hence making possible the identification of such hazards from the sole inspection of seismic data. The time occurrence and intensity of the snowmelt stages for each season have been identified and analyzed from the characteristics of the associated seismic records. In particular, the spectrograms of such episodes show a rich pattern of intensity and spectral variations. The availability of data covering 6 snow seasons allos to compare their variations in a long term scale. Since 2015 we are operating 2 additional stations located beside the Cinca and Segre Rivers, also in the Pyrenean range. First results confirm that the river-generated signal can be identified in the seismic data, even if it is often overlapped with wind-generated signal. Our objective is now to implement automatic procedures to identify seismic signals generated by large floods using data from seismic stations located near mountain rivers. On the other hand, we want to develop synthetic models of the seismic signal expected from bedload transport and water flow turbulence, with the final aim of using seismic data to estimate the bedload charge transported and hence constrain erosion studies in mountain environments. .(Founding: MISTERIOS project, CGL2013-48601-C2-1-R)Peer reviewe