Structural setting of the Čertovka landslide (Ústí nad Labem, Czech Republic): morphostructural analysis and electrical resistivity tomography

Abstract

The Èertovka land slide at Vaòov south of Ústí nad Labem, Czech Re pub lic, is de vel oped in a steep slope of the Labe River val ley (LRV). A ma jor ep i sode of landsliding oc curred in the first months of 1995, and the slope at Vaòov has been sub jected to geo log i cal and geomorphological in ves ti ga tion since then. This pa per pres ents the struc tural set ting of the Èertovka landslide based on the lat est geo log i cal sur vey, de tailed geomorphological map ping, morphostructural anal y sis and re sults of elec tri cal re sis tiv ity to mog ra phy. The land slide was found to be ini ti ated at the bound ary be tween Late Eocene to Oligocene ba saltic lavas above and volcaniclastics be low, with bed ding dip ping against the slope (anaclinal slope). The un der ly ing volcaniclastics show ten dency to argillization and have a much lower rock strength, which acts as an im por tant fac tor of slope in sta bil ity at the site. The Èertovka land slide is a com plex slope de for ma tion con sist ing of sev eral land slides and flowslides, with boul der streams merg ing into a boul der ac cu mu la tion fur ther downslope. The headscarp area of the landslide de vel oped at one of the struc tural lev els built by ba saltic lavas and form ing step-like mor phol ogy of the val ley slope. The headscarp co in cides with the course of a re gional E-W-strik ing Vaòov Fault that un der went mul ti ple tec tonic his tory and is as so ci ated with a dense frac ture sys tem in clud ing smooth slick en sides on the headscarp. Struc tural ob ser va tions com bined with de tailed knowl edge of the anat omy of the land slide based on air borne data, sur face data and geo phys i cal data per mit ted to con clude on struc tural con trols of landsliding and to pre dict fu ture evo lu tion of the slope de for ma tion. Fu ture landsliding will be ini ti ated at struc tural lev els of ba saltic rocks, with the headscarps de vel oped along frac tures par al lel to the Vaòov Fault. The prob a ble grad ual re treat of headscarps at the in di vid ual struc tural lev els along the slope pro file de notes a ret rogres sive land slide style.

CHILDA – Czech Historical Landslide Database

“…In NW Czechia, two major areas display high landslide susceptibility: (i) theČeské středohoří Mts (CS) built by Neogene volcanic rocks underlain by Mesozoic weak sediments (Cajz, 1999) with a susceptibility to landsliding (Hroch et al, 2002;Raška et al, 2014a;CHMI, 2021) and (ii) the Děčínská highland (DV) built by uplifted and dissected Mesozoic sandstones, which are prone to rockfalls and toppling (Kalvoda and Balatka, 1995;Zvelebil et al, 2005).…”

“…Similarly, Bíl et al (2020) combined different documentary and archaeological data to compile a chronology of landsliding in the Pavlovské vrchy (Czechia, OWC) and described the basic historical landslide terminology. The conceptual differences in hydrometeorological and geomorphologic hazards do not allow for uncritical transposition of the climatological insights into the historical landslide research and therefore call for new insights into the potential of the documentary data (Crozier and Glade, 1999;Raška et al, 2014b).…”

“…(c) Additional problems include uncertainties resulting from difficult to identify duplicities in records of different coverage (i.e. the issue of upscaling and downscaling) and from false frequency peaks caused by a combination of continual (regularly published) and stationary (published once as a collection of records) data (Raška et al, 2014b). Both these issues may result in false peaks and gaps in the landslide time series.…”

CHILDA − Czech Historical Landslide Database

“…The lithology of CS is built up of Neogene volcanic rocks, including basalts and phonolites and their volcaniclastics, surrounded or underlain by Mezosoic weak sedimentary rocks (Cajz, 1999). In a rugged terrain, such conditions often result in landsliding accelerated during the snow-melt season and heavy rainfalls (Hroch et al, 2002;Raška et al, 2014a;CHMI, 2020). DC is formed in an uplifted and dissected Mesozoic sandstones, which are prone to rockfalls and toppling (Kalvoda and Balatka, 1995;Zvelebil et al, 2005).…”