Differences in channel and hillslope geometry record a migrating uplift wave at the Mendocino Triple Junction

Clubb, F. J., Mudd, S. M., Hurst, M. D. and Grieve, S. W.D. (2020) Differences in channel and hillslope geometry record a migrating uplift wave at the Mendocino Triple Junction. Geology, 48(2), pp. 184-188. (doi: 10.1130/G46939.1)

Abstract

Tectonic plate motion, and the resulting change in land surface elevation, has been shown to have a fundamental impact on landscape morphology. Changes to uplift rates can drive a response in fluvial channels, which then drives changes to hillslopes. As hillslopes respond on different timescales than fluvial channels, investigating the geometry of channels and hillslopes in concert provides novel opportunities to examine how uplift rates may have changed through time. Here we perform coupled topographic analysis of channel and hillslope geometry across a series of catchments at the Mendocino Triple Junction (MTJ) in Northern California. These catchments are characterized by an order of magnitude difference in uplift rate from north to south. We find that dimensionless hillslope relief closely matches the uplift signal across the area and is positively correlated with channel steepness. Furthermore, the range of uncertainty in hillslope relief is lower than that of channel steepness, suggesting that it may be a more reliable recorder of uplift in the MTJ region. We find that hilltop curvature lags behind relief in its response to uplift, which in turn lags 23 behind channel response. These combined metrics show the northwards migration of the MTJ and the corresponding uplift field from topographic data alone.

• Item Type: Articles
• Additional Information: This work was supported by a Geo.X fellowship to Clubb, and a Natural Environment Research 192 Council grant NE/J009970/1 to Mudd.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hurst, Dr Martin
• Authors: Clubb, F. J., Mudd, S. M., Hurst, M. D., and Grieve, S. W.D.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Journal Name: Geology
• Publisher: Geological Society of America
• ISSN: 0091-7613
• ISSN (Online): 1943-2682
• Published Online: 09 December 2019
• Copyright Holders: Copyright © 2019 Geological Society of America
• First Published: First published in Geology 48(2):184-188
• Publisher Policy: Reproduced in accordance with the publisher copyright policy