Distributions of throws, widths and scarp slopes on normal faults and their relations to fault growth: insights from Auto_Throw code

Distributions of throws, widths and scarp slopes on normal faults and their relations to fault growth: insights from Auto_Throw code

Creators

Giampietro, Tiziano

Manighetti, Isabelle

Leclerc, Frédérique

Gaudemer, Yves

Description

The repository includes:

1. The Auto_Throw code

2. The topographic data (folder “DEMs”). Note that Les Saintes bathymetric data are available at https://doi.org/10.17882/96053).

3. Analysis Auto_Throw outputs obtained in the study (folder “Analysis_outputs”); namely, the topographic profiles as analyzed by Auto_Throw (along with raw topographic profiles for comparison). Each file concerns a given fault, as indicated in the file name.

4. Result Auto_Throw outputs obtained in the study (folder “Results_outputs”); namely the interpreted results obtained for each fault and each calculation (in doc Fi_Synthesis, with i the fault number).

5. Data compiled to build Figure 15.

Each Fi_Synthesis file includes:

(a) A Table synthesizing the Fault, DEM, and Run parameters

(b) Results from far-field slope measurements: maps of average far-field slope along each profile, and maps of far-field slope differences either side of the target scarp

(c) The final measurements obtained on the fault, for each run. Each page includes several figures: (A1): manual fault map (not used in the calculations); (A2): map of the final vertical offset measurements. Profiles are shown (red), along with the polygon (black) within which measurements are considered as concerning the target fault; (A3): 3D vision of the topographic profiles; (A4): Bivariate histogram showing the relative difference between any offset value and the final best offset along each profile (for a given scarp; i.e., within the polygon in A2), as a function of Th. Inset shows these differences globally; (B1): fault scarp and extracted topographic profiles. Fault tips are indicated in yellow; (B2): Final vertical offset profile, with measurements undiscriminated or discriminated based on expert assessment. Uncertainties are standard deviation of offsets among the dense population of “modal offsets”. If this population is small (e.g., Th < 40), the uncertainty is calculated as indicated in the corresponding pages (example in F5-Run 4); (B3): Final steepest (red) and mean (black) scarp slope profiles, with measurements undiscriminated or discriminated based on expert assessment. Uncertainties on steepest slopes are aleatory errors derived from the code, while uncertainties on mean slope are standard deviation of slope values among the dense population of “modal offsets”; (B4): Final fault (black) and scarp (green) width profiles, with measurements undiscriminated or discriminated based on expert assessment. Uncertainties on fault width are the standard deviation of the averaged values; (C1): Fault width measured at 2 lowest Th values; (C2): Fault width measured at 10 lowest Th values; (C3): Fault width measured at all Th values for population of “modal offsets”.

When several runs have been done, or several faults combine into a larger-scale system, or our results need to be compared to prior measurements, the compared or combined results are generally presented in the last few pages of the Fi_Synthesis file. For F5-Run 4, results are shown per individual fault. For Fish Slough, results are presented slightly differently as the objective is their comparison with those of Scott et al., 2022.