CaltechAUTHORS
  A Caltech Library Service

A physical model for seismic noise generation by turbulent flow in rivers

Gimbert, Florent and Tsai, Victor C. and Lamb, Michael P. (2014) A physical model for seismic noise generation by turbulent flow in rivers. Journal of Geophysical Research. Earth Surface, 119 (10). pp. 2209-2238. ISSN 2169-9003. http://resolver.caltech.edu/CaltechAUTHORS:20150106-082010292

[img] PDF - Published Version
See Usage Policy.

10Mb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20150106-082010292

Abstract

Previous studies suggest that the seismic noise induced by rivers may be used to infer river transport properties, and previous theoretical work showed that bedload sediment flux can be inverted from seismic data. However, the lack of a theoretical framework relating water flow to seismic noise prevents these studies from providing accurate bedload fluxes and quantitative information on flow processes. Here we propose a forward model of seismic noise caused by turbulent flow. In agreement with previous observations, modeled turbulent flow-induced noise operates at lower frequencies than bedload-induced noise. Moreover, the differences in the spectral signatures of turbulent flow-induced and bedload-induced forces at the riverbed are significant enough that these two processes can be characterized independently using seismic records acquired at various distances from the river. In cases with isolated turbulent flow noise, we suggest that riverbed stress can be inverted. Finally, we validate our model by comparing predictions to previously reported observations. We show that our model captures the spectral peak located around 6–7 Hz and previously attributed to water flow at Hance Rapids in the Colorado River (United States); we also show that turbulent flow causes a significant part of the seismic noise recorded at the Trisuli River in Nepal, which reveals that the hysteresis curve previously reported there does not solely include bedload, but is also largely influenced by turbulent flow-induced noise. We expect the framework presented here to be useful to invert realistic bedload fluxes by enabling the removal of the turbulent flow contribution from seismic data.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1002/2014JF003201DOIArticle
http://onlinelibrary.wiley.com/doi/10.1002/2014JF003201/abstractPublisherArticle
ORCID:
AuthorORCID
Gimbert, Florent0000-0001-7350-3563
Tsai, Victor C.0000-0003-1809-6672
Lamb, Michael P.0000-0002-5701-0504
Additional Information:© 2014 American Geophysical Union. Received 5 MAY 2014; Accepted 15 SEP 2014; Accepted article online 18 SEP 2014; Published online 16 OCT 2014. We thank B. Schmandt for providing data and J.G. Venditti as well as J.-P. Avouac for interesting discussions. We thank two anonymous reviewers and D. Roth for helpful reviews. M.P.L acknowledges funding from the Terrestrial Hazards Observations and Reports Programs at Caltech and NSF grant EAR-1349115. F.G. was partially supported by funding from the Tectonics Observatory.
Group:Caltech Tectonics Observatory, Seismological Laboratory
Funders:
Funding AgencyGrant Number
Caltech Terrestrial Hazards Observations and Reporting center (THOR)UNSPECIFIED
NSFEAR-1349115
Caltech Tectonics ObservatoryUNSPECIFIED
Subject Keywords:turbulence; seismic noise; force fluctuations; river; bedload
Record Number:CaltechAUTHORS:20150106-082010292
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20150106-082010292
Official Citation:Gimbert, F., V. C. Tsai, and M. P. Lamb (2014), A physical model for seismic noise generation by turbulent flow in rivers, J. Geophys. Res. Earth Surf., 119, 2209–2238, doi:10.1002/2014JF003201
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:53200
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:06 Jan 2015 18:20
Last Modified:23 Nov 2016 19:32

Repository Staff Only: item control page