CaltechAUTHORS
  A Caltech Library Service

Competing effects of mountain uplift and landslide erosion over earthquake cycles

Li, Gen and West, A. Joshua and Qiu, Hongrui (2019) Competing effects of mountain uplift and landslide erosion over earthquake cycles. Journal of Geophysical Research: Solid Earth, 124 (5). pp. 5101-5133. ISSN 0148-0227. https://resolver.caltech.edu/CaltechAUTHORS:20190412-073948682

[img] PDF - Published Version
See Usage Policy.

4Mb

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20190412-073948682

Abstract

Large earthquakes can construct mountainous topography by inducing rock uplift but also erode mountains by causing landslides. Observations following the 2008 Wenchuan earthquake show that landslide volumes in some cases match seismically induced uplift, raising questions about how the actions of individual earthquakes accumulate to build topography. Here we model the two‐dimensional surface displacement field generated over a full earthquake cycle accounting for coseismic deformation, postseismic relaxation, landslide erosion, and erosion‐induced isostatic compensation. We explore the related volume balance across different seismotectonic and topographic conditions and revisit the Wenchuan case in this context. The ratio (Ω) between landslide erosion and uplift is most sensitive to parameters determining landslide volumes (particularly earthquake magnitude M_w, seismic energy source depth, and failure susceptibility, as well as the seismological factor responsible for triggering landslides), and is moderately sensitive to the effective elastic thickness of lithosphere, T_e. For a specified magnitude, more erosive events (higher Ω) tend to occur at shallower depth, in thicker‐T_e lithosphere, and in steeper, more landslide‐prone landscapes. For given landscape and seismotectonic conditions, the volumes of both landslides and uplift to first order positively scale with Mw and seismic moment M_o. However, higher M_w earthquakes generate lower landslide and uplift volumes per unit M_o, suggesting lower efficiency in the use of seismic energy to drive topographic change. With our model, we calculate the long‐term average seismic volume balance for the eastern Tibetan region and find that the net topographic effect of earthquakes in this region tends to be constructive rather than erosive. Overall, destructive events are rare when considering processes over the full earthquake cycle, although they are more likely if only considering the coseismic volume budget (as was the case for the 2008 Wenchuan earthquake where landsliding substantially offset coseismic uplift). Irrespective of the net budget, our results suggest that the erosive power of earthquakes plays an important role in mountain belt evolution, including by influencing structures and spatial patterns of deformation, for example affecting the wavelength of topography.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1029/2018JB016986DOIArticle
ORCID:
AuthorORCID
Li, Gen0000-0002-6300-3570
West, A. Joshua0000-0001-6909-1471
Qiu, Hongrui0000-0002-4219-0039
Additional Information:© 2019 American Geophysical Union. Received 13 JAN 2018; Accepted 3 APR 2019; Accepted article online 9 APR 2019. This work was funded by the U.S. National Science Foundation (NSF‐EAR/GLD grants 1053504 and 1640894 to A.J.W.). G.L. was supported by a USC Dornsife college graduate merit fellowship. We thank Jean‐Philippe Avouac, Sylvain Barbot, Alexander Densmore, Josh Roering, Niels Hovius, Odin Marc, Patrick Meunier, Yehuda Ben‐Zion, James Dolan, Luca Dal Zilio, Lei Qin, Haoran Meng, Chris Milliner, Zhigang Peng, Mong‐Han Huang, Lingsen Meng, and Joel Scheingross for their helpful discussions. G.L. thanks Wanbin Chen for the discussions about several mathematical problems involved in this work. We thank three reviewers and the Editor for their insightful and constructive comments that helped to improve an earlier version of the manuscript, and we appreciate the editorial handling. This paper is mainly built on the results from a numerical model, and the adopted Wenchuan seismic deformation and landslide data are contained in multiple published sources cited in references.
Group:Seismological Laboratory
Funders:
Funding AgencyGrant Number
NSFEAR-1053504
NSFEAR-1640894
University of Southern CaliforniaUNSPECIFIED
Issue or Number:5
Record Number:CaltechAUTHORS:20190412-073948682
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20190412-073948682
Official Citation:Li, G., West, A. J., & Qiu, H. (2019). Competing effects of mountain uplift and landslide erosion over earthquake cycles. Journal of Geophysical Research: Solid Earth, 124, 5101–5133. https://doi.org/10.1029/2018JB016986
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:94678
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:12 Apr 2019 14:54
Last Modified:05 Nov 2019 17:57

Repository Staff Only: item control page