Fluvial seismology

Fluvial seismology is the application of seismological methods to understand river processes, such as discharge, erosion, and streambed evolution. Flowing water and the movement of sediments along the streambed generate elastic (seismic) waves that propagate into the surrounding Earth materials.[1][2] Seismometers can record these signals, which can be analyzed to illuminate different fluvial processes such as turbulent water flow and bedload transport.[1] Seismic methods have been used to observe discharge values that range from single-digits[3] up through tens of thousands of cubic feet per second (cfs).[1]

An experiment in 1990 in the Italian Alps was one of the earliest to demonstrate that seismometers could detect discernible fluvial signals within the seismic noise generated by flow.[3] Six seismometers recorded average velocity of ground oscillations along an alpine river that was also monitored for discharge and bedload with a sediment trap.[3] They determined the lowest flow values require to initiate and maintain bedload transport.[3] Since then, fluvial seismology has become a rapidly growing area of research.

Fluvial seismology is a sub-discipline of environmental seismology, a relatively young field in which unconventional seismic signals can be detected within what was previously considered ‘noise’.[4][5] Seismic noise is found across the full spectrum of frequencies studied in seismology (0.001–100 Hz).[6] While traditional seismology is concerned with tectonic earthquakes and the structure of the solid earth,[5] environmental seismology is concerned with waves that originate from outside the solid earth or whose signal is affected by environmental conditions (temperature, hydrology).[4] The principles of fluvial and environmental seismology can be applied to all sorts of surficial processes, including debris flows, landslides, lahars, glacial movement and icequakes, etc.

  1. ^ a b c Schmandt, Brandon; Aster, Richard C.; Scherler, Dirk; Tsai, Victor C.; Karlstrom, Karl (2013). "Multiple fluvial processes detected by riverside seismic and infrasound monitoring of a controlled flood in the Grand Canyon". Geophysical Research Letters. 40 (18): 4858–4863. Bibcode:2013GeoRL..40.4858S. doi:10.1002/grl.50953. ISSN 0094-8276. S2CID 129733846.
  2. ^ Hsu, Leslie; Finnegan, Noah J.; Brodsky, Emily E. (2011). "A seismic signature of river bedload transport during storm events: SEISMIC SIGNATURE OF RIVER BEDLOAD". Geophysical Research Letters. 38 (13): n/a. doi:10.1029/2011GL047759. S2CID 3069731.
  3. ^ a b c d Govi, Mario; Maraga, Franca; Moia, Fabio (1993). "Seismic detectors for continuous bed load monitoring in a gravel stream". Hydrological Sciences Journal. 38 (2): 123–132. doi:10.1080/02626669309492650. ISSN 0262-6667.
  4. ^ a b Larose, Eric; Carrière, Simon; Voisin, Christophe; Bottelin, Pierre; Baillet, Laurent; Guéguen, Philippe; Walter, Fabian; Jongmans, Denis; Guillier, Bertrand; Garambois, Stéphane; Gimbert, Florent (2015). "Environmental seismology: What can we learn on earth surface processes with ambient noise?". Journal of Applied Geophysics. 116: 62–74. Bibcode:2015JAG...116...62L. doi:10.1016/j.jappgeo.2015.02.001.
  5. ^ a b Montagner, Jean-Paul; Mangeney, Anne; Stutzmann, Eléonore (2020), "Seismology and Environment", in Gupta, Harsh K. (ed.), Encyclopedia of Solid Earth Geophysics, Encyclopedia of Earth Sciences Series, Cham: Springer International Publishing, pp. 1–8, doi:10.1007/978-3-030-10475-7_258-1, ISBN 978-3-030-10475-7, S2CID 240739967, retrieved 2021-11-16
  6. ^ Burtin, A.; Bollinger, L.; Vergne, J.; Cattin, R.; Nábělek, J. L. (2008). "Spectral analysis of seismic noise induced by rivers: A new tool to monitor spatiotemporal changes in stream hydrodynamics". Journal of Geophysical Research. 113 (B5): B05301. Bibcode:2008JGRB..113.5301B. doi:10.1029/2007JB005034. ISSN 0148-0227. S2CID 53452574.