Data for "Coarsening of fluvial sediments after the Gorkha Earthquake 2015, Nepal."

The data are supplementary material to:David Puhl, Jens M. Turowski, Christoff Andermann, Michael Dietze, Kristen L. Cook, Gen Li, Basanta R.Adhikari (submitted), Coarsening of fluvial sediments after the Gorkha Earthquake 2015, Nepal, JGREarth Surface, DOI to be added Sampling Method: The samples were collected from the surface of sediment sources during two field campaigns in the Bhotekoshi catchment in 2016 and 2018. Samples from 2016 were sieved in the field down to 600 µm. Analytical procedure: Samples were filtered onsite through a 0.22 µm PES filter using a head pressure filtration chamber. Each sample is composed of 6 sequential 500ml water samples that were combined before filtering. Samples were rinsed off the filter paper at the GFZ Sedimentary Laboratory SedLab and oven dried by 40°C and weighted. 40°C drying temperature was chosen to not degraded organic compounds contained in the suspended sediment load in order to preserve the sample for further analysis. Suspendedsediment concentration was derived by dividing the bulk weight with the 3 liters sample volume. The samples were analyzed for grainsize distribution by laser diffraction, requiring <1g of a representative sample aliquot. The aliquots were treated with 10% H2O2 for oxidation of organic materials and 10% HCl for 48 hours to remove the calcium carbonate fraction. Thus, only the pure mineral composition of the sample was analyzed. Prior to measurement the sample material was dispersed with sodiumpyrophosphate for 24 h and placed in an ultrasonic bath for 15 minutes. Grain size measurements were conducted by laser diffraction using a Horiba-Retsch Laser Particle Size Analyzer LA-950. This machine measures in a range from 0.011 μm to 2500 μm over 92 classes. To prevent coalescence of grains samples were again treated by ultrasonic excitation within the analytical device for 10 seconds directly before each measurement. Measurements were repeated 10 times with each 2000 sensor acquisitions. The diffraction measures were evaluated using a Mie scatter model (refraction index: 1.55 and absorption index: 1.33). Data processing: The laser diffraction measures were evaluated using a Mie scatter model (refraction index: 1.55 and absorption index: 1.33). The 10 repeat measurements were totaled for mean and median values. File description: landslide_2016.csv Column 1: sample name Column 2-93: Grain size classes from 0.011 to 2500 µm Column 94-96: location Column 98: Mineralogy grainsize_sample 2018.csv Column 1: sample name Column 2-93: Grain size classes from 0.011 to 2500 µm Column 94: checkplace* Column 95-96: location Column 97: Mineralogy * The column "checkplace" indicates "f" for fluvial deposits, "d" for debris flow deposits, and "l" for landslide deposits.