JpGU-AGU Joint Meeting 2017

Presentation information

[EE] Poster

H (Human Geosciences) » H-DS Disaster geosciences

[H-DS09] [EE] Landslides and related phenomena

Wed. May 24, 2017 3:30 PM - 5:00 PM Poster Hall (International Exhibition Hall HALL7)

convener:Masahiro Chigira(Disaster Prevention Research Institute, Kyoto University), Gonghui Wang(Disaster Prevention Research Institute, Kyoto University), Fumitoshi Imaizumi(Faculty of Agriculture, Shizuoka University)

[HDS09-P09] Employing electron microscopy integrated with X-ray spectroscopy for Kuntawa Landslide assessment

*Patrick Nkemakonam Dikedi1 (1.Veritas University)

Keywords:EDS, Particlemetric, SEM, Micro-fault, topography

This work centres on Kuntawa landslide assessment owing to the enigmatic nature of a 2003 landslide which buried 4 people and a truck in Kuntawa village, of Nigeria.
A Phenom ProX Scanning Electron Microscope (SEM) integrated with Energy dispersive X-ray Spectroscopy (EDS) and Particlemetric software was employed to generate morphology, particle size data, elemental identification data and topography (at 3500x) of earth samples scooped from the landslide site.
For a core sample 1 at depth, d=3.75m, average circle equivalent diameter, area and volume by area of 11.5 µm, 249 µm² and 3680µm³ were generated respectively; at d=3.785m, , and of 6.19µm, 30.1µm² and 124µm³ were generated respectively; at d=3.82m, , and of 11.5 µm, 130 µm² and 1380µm³ were generated respectively. For a core sample 2, at d=3.75m, and of 5.54 µm, 26 µm² and 108µm³ were generated respectively; at d=3.82m, , and of 19.4µm, 338µm² and 5240µm³ were generated respectively; 243 particles were scanned.
One of the results from specific surface for samples 1 and 2, reveals that it would take twice and four times the amount of water needed to wet an entire surface both at d=3.82m than at d=3.785m and d=3.75m respectively.
Additional laboratory facilities reveal that soil water content, volumetric water content, porosity, soil water-filled pore space bulk density, decreased with increasing—this situation may have contributed to this earth surface event.
Elemental composition at the landslide site were generated from the EDS: oxygen (O), Silicon (Si), Bromine (Br), iron (Fe), Carbon (C) and Aluminium (Al). O and C had the highest and lowest concentration of elemental compositions of 68.5% at 3.75m depth and 1% at 3.82m depth for samples 1 and 2, respectively. The significant amount of oxygen unravelled from the result, is suggestive of algae presence at the landslide site—intense soil microbial activity may have contributed to landslide occurrence. Micro-faults from granular topography and morphology are probably tips of bigger faults down below—inferring that past earth tremor events may have occurred leading to landslide.