Three-dimensional surface deformation derived from airborne interferometric UAVSAR: Application to the Slumgullion Landslide

Journal of Geophysical Research B: Solid Earth
By: , and 

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Abstract

In order to provide surface geodetic measurements with “landslide-wide” spatial coverage, we develop and validate a method for the characterization of 3-D surface deformation using the unique capabilities of the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) airborne repeat-pass radar interferometry system. We apply our method at the well-studied Slumgullion Landslide, which is 3.9 km long and moves persistently at rates up to ∼2 cm/day. A comparison with concurrent GPS measurements validates this method and shows that it provides reliable and accurate 3-D surface deformation measurements. The UAVSAR-derived vector velocity field measurements accurately capture the sharp boundaries defining previously identified kinematic units and geomorphic domains within the landslide. We acquired data across the landslide during spring and summer and identify that the landslide moves more slowly during summer except at its head, presumably in response to spatiotemporal variations in snowmelt infiltration. In order to constrain the mechanics controlling landslide motion from surface velocity measurements, we present an inversion framework for the extraction of slide thickness and basal geometry from dense 3-D surface velocity fields. We find that the average depth of the Slumgullion Landslide is 7.5 m, several meters less than previous depth estimates. We show that by considering a viscoplastic rheology, we can derive tighter theoretical bounds on the rheological parameter relating mean horizontal flow rate to surface velocity. Using inclinometer data for slow-moving, clay-rich landslides across the globe, we find a consistent value for the rheological parameter of 0.85 ± 0.08.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Three-dimensional surface deformation derived from airborne interferometric UAVSAR: Application to the Slumgullion Landslide
Series title Journal of Geophysical Research B: Solid Earth
DOI 10.1002/2015JB012559
Volume 121
Issue 5
Year Published 2016
Language English
Publisher AGU
Contributing office(s) Geologic Hazards Science Center
Description 27 p.
First page 3951
Last page 3977
Country United States
State Colorado
Other Geospatial Slumgullion landslide