Ground fissures within the Main Ethiopian Rift: Tectonic, lithological and piping controls

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985891%3A_____%2F21%3A00551182" target="_blank" >RIV/67985891:_____/21:00551182 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00025798:_____/21:00000203 RIV/00216208:11310/21:10437306

Výsledek na webu

<a href="https://onlinelibrary.wiley.com/doi/10.1002/esp.5227" target="_blank" >https://onlinelibrary.wiley.com/doi/10.1002/esp.5227</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/esp.5227" target="_blank" >10.1002/esp.5227</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Ground fissures within the Main Ethiopian Rift: Tectonic, lithological and piping controls

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

Ground fissures within the Main Ethiopian Rift: Tectonic, lithological and piping controls

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Earth Surface Processes and Landforms

ISSN

0197-9337

e-ISSN

1096-9837

Svazek periodika

46

Číslo periodika v rámci svazku

15

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

17

Strana od-do

3158-3174

Kód UT WoS článku

000700628100001

EID výsledku v databázi Scopus

2-s2.0-85115722867