CaltechAUTHORS
  A Caltech Library Service

Numerical model predictions of autogenic fluvial terraces and comparison to climate change expectations

Limaye, Ajay B. S. and Lamb, Michael P. (2016) Numerical model predictions of autogenic fluvial terraces and comparison to climate change expectations. Journal of Geophysical Research. Earth Surface, 121 (3). pp. 512-544. ISSN 2169-9003. http://resolver.caltech.edu/CaltechAUTHORS:20160520-102347604

[img] PDF - Published Version
See Usage Policy.

4Mb
[img] MS Word (Captions for Movies S1-S7) - Supplemental Material
See Usage Policy.

61Kb
[img] Video (AVI) (Movie S1) - Supplemental Material
See Usage Policy.

5Mb
[img] Video (AVI) (Movie S2) - Supplemental Material
See Usage Policy.

9Mb
[img] Video (AVI) (Movie S3) - Supplemental Material
See Usage Policy.

20Mb
[img] Video (AVI) (Movie S4) - Supplemental Material
See Usage Policy.

20Mb
[img] Video (AVI) (Movie S5) - Supplemental Material
See Usage Policy.

20Mb
[img] Video (AVI) (Movie S6) - Supplemental Material
See Usage Policy.

9Mb
[img] Video (AVI) (Movie S7) - Supplemental Material
See Usage Policy.

9Mb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20160520-102347604

Abstract

Terraces eroded into sediment (alluvial) and bedrock (strath) preserve an important history of river activity. River terraces are thought to form when a river switches from a period of slow vertical incision and valley widening to fast vertical incision and terrace abandonment. Consequently, terraces are often interpreted to reflect changing external drivers including tectonics, sea level, and climate. In contrast, the intrinsic unsteadiness of lateral migration in rivers may generate terraces even under constant rates of vertical incision without external forcing. To explore this mechanism, we simulate landscape evolution by a vertically incising, meandering river and isolate the age and geometry of autogenic river terraces. Modeled autogenic terraces form for a wide range of lateral and vertical incision rates and are often paired and longitudinally extensive for intermediate ratios of vertical-to-lateral erosion rate. Autogenic terraces have a characteristic reoccurrence time that scales with the time for relief generation. There is a preservation bias against older terraces due to reworking of previously visited parts of the valley. Evolving, spatial differences in bank strength between bedrock and sediment reduce terrace formation frequency and length, favor pairing, and can explain sublinear terrace margins at valley boundaries. Age differences and geometries for modeled autogenic terraces are consistent, in cases, with natural terraces and overlap with metrics commonly attributed to terrace formation due to climate change. We suggest a new phase space of terrace properties that may allow differentiation of autogenic terraces from terraces formed by external drivers.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1002/2014JF003392DOIArticle
http://onlinelibrary.wiley.com/doi/10.1002/2014JF003392/abstractPublisherArticle
ORCID:
AuthorORCID
Lamb, Michael P.0000-0002-5701-0504
Additional Information:© 2016 American Geophysical Union. Received 14 NOV 2014; Accepted 2 FEB 2016; Accepted article online 8 FEB 2016; Published online 3 MAR 2016. This work was supported by the Department of Defense through the National Defense Science and Engineering Graduate Fellowship (NDSEG) Program and NSF grant EAR-1147381 to M.P.L. Acknowledgment is also made to the donors of the American Chemical Society Petroleum Research Fund for partial support of this research. Model data and digitized terrace maps from this manuscript are available upon request. We thank Bob Anderson, Jean-Philippe Avouac, Patrick Belmont, Noah Finnegan, Dirk Scherler, and Andrew Thompson for their insightful discussions. We acknowledge Alexander Densmore, Nicole Gasparini, Alex Whittaker, Stephen Lancaster, and John Buffington for detailed and constructive formal reviews.
Funders:
Funding AgencyGrant Number
National Defense Science and Engineering Graduate (NDSEG) FellowshipUNSPECIFIED
NSFEAR-1147381
American Chemical Society Petroleum Research FundUNSPECIFIED
Record Number:CaltechAUTHORS:20160520-102347604
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20160520-102347604
Official Citation:Limaye, A. B. S., and M. P. Lamb (2016), Numerical model predictions of autogenic fluvial terraces and comparison to climate change expectations, J. Geophys. Res. Earth Surf., 121, 512–544, doi:10.1002/2014JF003392
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:67201
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:20 May 2016 17:35
Last Modified:02 Sep 2016 19:06

Repository Staff Only: item control page