Work Description

Date: June 12 2024

Dataset Title: Model code and data related to "Regional Back-Analysis of Earthquake Triggered Landslide Inventories: a 2D Method for Estimating Rock Strength from Remote Sensing Data" a study by Medwedeff et al. in review in JGR Earth Surface, 2024

Dataset creators: Medwedeff, W.G., Clark, M.K, and Zekkos, D.

Dataset contact: William Medwedeff, wmedwed@umich.edu, bill.medwedeff@wa.dnr.gov

Funding: NSF-EAR 164079, USGS Award Number G17AP00088

Content Description:
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Contents of DeepBlue repository associated with Medwedeff et al. (submitted to JGR Earth Surface September 29 2023):
The matlab code, digital elevation data, and landslide volume data here support the findings of Medwedeff et al. (2024) in JGR: Earth Surface. In this article, we study past landslides to understand how the strength of rocks and soil vary across the landscape and below the ground. We develop a matlab-based model that uses the length, width, slope angle, and thickness of landslides that have occurred in the past to estimate how strong the rock or soil was before it gave way. We improve upon previous studies by using elevation data from before and after landslides occurred to measure how thick the sliding mass was for each landslide. The thickness measurements help us understand how the strength of the ground changes as a function of depth below the surface, like for example, when rocks get weaker near the surface due to increased weathering. We apply our model to landslides that occurred during earthquakes in Greece and Nepal, and we compare the results to rock strength field data.

In addition to our model code, we include in this data repository the landslide volume and elevation data for Nepal and Greece that we used to run our model for this study. Specifically, these data are digital elevation models (DEMs) for Lefkada, Greece, and Melamchi Valley, Nepal, landslide volume data for the same two regions, and processed seismic data consisting of 1 dimensional shear-wave velocity profiles for the study area in Greece. The elevation data for Greece is a 2 meter resolution DEM produced in 2015 by the Hellenic Mapping and Cadastral Organization. The elevation data for Nepal is a 2 meter DEM produced by satellite photogrammetry by Atwood and West, 2022. Landslide volumes for the Greece and Nepal study areas were produced by processing the elevation data as described in detail in the JGR Earth Surface journal article associated with this repository. The 1 dimensional seismic profiles for the Greece study area were collected with a Geometrics Geode Seismograph and 4.5 Hz vertical component geophones laid out in a linear array. A 10 lb sledgehammer was struck against a 5 cm thick plastic plate to generate the impulsive energy source. We used 24 channel seismic arrays and between 0.30 and 3.05 meter (1-10 ft) spacing between geophones depending on the space available at each site. We analyzed dispersion curves and performed inversions for shear wave velocity using the software Seisimager.

LIST OF FILES IN DATA REPOSITORY:
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File: “Data_Repository-20240521T155832Z-001.zip”
Description: Contains all model code and data used to generate the figures in Medwedeff et al., 2024. See below for an explanation of the folders contained within:

• Case Study 1 – Contains all model code and data used to generate figures 1-5 of Medwedeff et al., 2024
o Case Study 1 Results – Contains code-generated plots underlying figures 1-5 of Medwedeff et al 2024
o Code – Contains all matlab code related to Case Study 1 in Medwedeff et al., 2024. Run the script “Case_Study_1.m” to generate all figures related to Case Study 1.
o Rasters – contains Lefkada, Greece digital elevation data used in the Case Study 1 analyses
o VolumeAreaData – Contains 2015 Lefkada landslide volume and area data used in the analyses related to Case Study 1.
o Vs_Data – contains 1D seismic shear wave velocity profiles used in the analysis presented in figure 5 of Medwedeff et al., 2024.

• Case Study 2 – Contains all model code and data used to generate figures 7-9 of Medwedeff et al., 2024
o Case Study 2 Results – Contains code-generated plots underlying figures 7-9 of Medwedeff et al 2024
o Code – Contains all matlab code related to Case Study 2 in Medwedeff et al., 2024. Run the script “Case_Study_2.m” to generate all figures related to Case Study 2.
o Rasters – contains Nepal digital elevation data used in the Case Study 2 analyses
o VolumeAreaData – Contains 2015 Lefkada landslide volume and area data used in the analyses related to Case Study 1.

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For questions please contact:
William Medwedeff
wmedwed@umich.edu, bill.medwedeff@wa.dnr.gov
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References:
Medwedeff, W.G., Clark, M.K., Zekkos, D. (in review 2024) Regional Back-Analysis of Earthquake Triggered Landslide Inventories: a 2D Method for Estimating Rock Strength from Remote Sensing Data. In review in JGR Earth Surface 2024
Atwood, A., West, A.J. (2022). Evaluation of high-resolution DEMs from satellite imagery for geomorphic applications: A case study using the SETSM algorithm. Earth Surface Processes and Landforms. 47(3), 706-722.