Estimating rates of debris flow entrainment from ground vibrations

Geophysical Research Letters
By: , and 

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Abstract

Debris flows generate seismic waves as they travel downslope and can become more dangerous as they entrain sediment along their path. We present field observations that show a systematic relation between the magnitude of seismic waves and the amount of erodible sediment beneath the flow. Specifically, we observe that a debris flow traveling along a channel filled initially with sediment 0.34m thick generates about 2 orders of magnitude less spectral power than a similar-sized flow over the same channel without sediment fill.We adapt amodel fromfluvial seismology to explain this observation and then invert it to estimate the level of bed sediment (and rate of entrainment) beneath a passing series of surges. Our estimates compare favorably with previous direct measurements of entrainment rates at the site, suggesting the approach may be a new indirect way to obtain rare field constraints needed to test models of debris flow entrainment.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Estimating rates of debris flow entrainment from ground vibrations
Series title Geophysical Research Letters
DOI 10.1002/2015GL064811
Volume 42
Issue 15
Year Published 2015
Language English
Publisher AGU
Contributing office(s) Geologic Hazards Science Center
Description 8 p.
First page 6365
Last page 6372
Country United States
State Colorado
Other Geospatial Chalk Cliffs