Počet záznamů: 1
Ground fissures within the Main Ethiopian Rift: Tectonic, lithological and piping controls
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SYSNO ASEP 0551182 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Ground fissures within the Main Ethiopian Rift: Tectonic, lithological and piping controls Tvůrce(i) Valenta, J. (CZ)
Verner, K. (CZ)
Martínek, K. (CZ)
Hroch, T. (CZ)
Buriánek, D. (CZ)
Megerssa, L.A. (CZ)
Boháč, J. (CZ)
Kassa, M. (ET)
Legesse, F. (ET)
Yakob, M. (ET)
Kebede, B. (ET)
Málek, Jiří (USMH-B) RID, ORCID, SAICelkový počet autorů 12 Zdroj.dok. Earth Surface Processes and Landforms. - : Wiley - ISSN 0197-9337
Roč. 46, č. 15 (2021), s. 3158-3174Poč.str. 17 s. Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova geomechanical properties ; pipe collapses ; pyroclastics ; seismic anisotropy ; soil ; subsurface erosion ; surface waves ; unconsolidated sediments Vědní obor RIV DB - Geologie a mineralogie Obor OECD Geology Způsob publikování Omezený přístup Institucionální podpora USMH-B - RVO:67985891 UT WOS 000700628100001 EID SCOPUS 85115722867 DOI 10.1002/esp.5227 Anotace Ground fissures, especially if they open due to a sudden collapse of the surface, is a serious risk for populated areas. Their common occurrence in unconsolidated sediments of the Main Ethiopian Rift was found to be mostly a result of piping. The fissures start by piping in linear sub-horizontal underground voids, which often propagate upwards resulting in ceiling collapse and formation of deep and long ground fissures with vertical walls. In the southern and central Main Ethiopian Rift the fissures pose a serious risk to infrastructure and settlements. The ground fissures are often linear (up to several kilometres long and often tens of metres deep) and accompanied by sinkholes (along the length). A detailed field mapping of the geological (rock composition, orientation and character of lithological boundaries, primary fabrics and brittle structures) and geomorphological features (especially a length, width and depth of fissures, sinkholes and gullies) followed by in situ seismic anisotropy measurements and a laboratory determination of the geomechanical properties of volcanoclastic deposits was carried out to investigate the ground fissures' origin. The conditions and factors leading to the formation of the ground fissures have been linked to: (a) the presence of regional normal faults and the associated extensional joints and (b) the alternation of lithological units with contrasting hydraulic permeability. The latter corresponds to a sequence of less permeable hard rocks (e.g., rhyolitic ignimbrites) overlain by heterogeneous, soft and permeable, unconsolidated volcaniclastic deposits with a low amount of clay (less than 10%). The ground fissures' occurrence has shown affiliation to areas which have a significantly high seismic anisotropy (more than 20% at the study sites), which can be used as a proxy to map out high risk areas prone to piping and ground fissure formation. Pracoviště Ústav struktury a mechaniky hornin Kontakt Iva Švihálková, svihalkova@irsm.cas.cz, Tel.: 266 009 216 Rok sběru 2022 Elektronická adresa https://onlinelibrary.wiley.com/doi/10.1002/esp.5227
Počet záznamů: 1