Multiple fluvial processes detected by riverside seismic and infrasound monitoring of a controlled flood in the Grand Canyon
Abstract
As rivers transport water and sediment across Earth's surface, they radiate elastic and acoustic waves. We use seismic and infrasound observations during a controlled flood experiment (CFE) in the Grand Canyon to show that three types of fluvial processes can be monitored from outside the channel. First, bed-load transport under conditions of evolving bed mobility is identified as the dominant seismic source between 15 and 45 Hz. Two lower-frequency seismic bands also excited by the CFE exhibited greater power increases and are consistent with source processes related to fluid rather than sediment transport. The second fluvial seismic source is inferred to be fluid tractions on the rough riverbed, which drive the maximum seismic power increase at 0.73 Hz, but do not excite infrasound. Waves at the fluid-air interface are suggested as a third source, which generates a common 6–7 Hz peak in seismic and infrasound responses to the CFE.
Additional Information
© 2013 American Geophysical Union. Received 28 July 2013; revised 6 September 2013; accepted 9 September 2013; published 18 September 2013. We thank M. Hahn and R. Newton from the National Park Service, and J. Schmidt, C. Fritzinger, N. Voichick, and R. Tusso from the Grand Canyon Monitoring and Research Center for making it possible to use this exceptional science opportunity. The IRIS PASSCAL Instrument Center, and particularly P. Miller and G. Slad are thanked for instrument and data handling support. E. Aster assisted with fieldwork. Mike Lamb provided informal feedback. Two anonymous reviewers helped improve the manuscript. B.S. acknowledges Caltech for time to conduct fieldwork and support for this research from the University of New Mexico. [24] The Editor thanks two anonymous reviewers for their assistance in evaluating this paper.Attached Files
Published - grl50953.pdf
Supplemental Material - HR_aux_figs.pdf
Supplemental Material - readme.pdf
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Additional details
- Eprint ID
- 42332
- Resolver ID
- CaltechAUTHORS:20131108-093414888
- Created
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2013-11-11Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Seismological Laboratory