Real and apparent changes in sediment deposition rates through time
Article first published online: 30 SEP 2009
Copyright 2009 by the American Geophysical Union.
Journal of Geophysical Research: Earth Surface (2003–2012)
Volume 114, Issue F3, September 2009
How to Cite
2009), Real and apparent changes in sediment deposition rates through time, J. Geophys. Res., 114, F00A06, doi:10.1029/2009JF001266., and (
- Issue published online: 30 SEP 2009
- Article first published online: 30 SEP 2009
- Manuscript Accepted: 2 JUL 2009
- Manuscript Revised: 11 MAY 2009
- Manuscript Received: 15 JAN 2009
- deposition rates;
- heavy tails
 Field measurements show that estimated sediment deposition rate decreases as a power law function of the measurement interval. This apparent decrease in sediment deposition has been attributed to completeness of the sedimentary record; the effect arises because of incorporation of longer hiatuses in deposition as averaging time is increased. We demonstrate that a heavy-tailed distribution of periods of nondeposition (hiatuses) produces this phenomenon and that observed accumulation rate decreases as tγ−1, over multiple orders of magnitude, where 0 < γ ≤ 1 is the parameter describing the tail of the distribution of quiescent period length. By using continuous time random walks and limit theory, we can estimate the actual average deposition rate from observations of the surface location over time. If geologic and geometric constraints place an upper limit on the length of hiatuses, then average accumulation rates approach a constant value at very long times. Our model suggests an alternative explanation for the apparent increase in global sediment accumulation rates over the last 5 million years.