Sackungen represents a common mode of deep-seated rock-slope failures in alpine landscapes, but p... more Sackungen represents a common mode of deep-seated rock-slope failures in alpine landscapes, but proof of their temporal and causal relationship to extrinsic factors such as climatic changes, glacier retreat or seismic activity remains elusive. Based on the terrestrial cosmogenic nuclide (TCN) dating of 18 sackung scarps supported by one radiocarbon-dated scarp, we reconstructed the post-glacial chronology of sackungen in the Tatra Mts. (central Europe, Slovakia and Poland), the highest part of the Carpathians. The obtained ages (~15.7 e 4.3 ka) indicate that sackungen post-date the regional LGM and some of them originated soon after the glacier withdrawal from adjacent valleys. Furthermore, systematic decrease of scarp ages with their increasing altitude suggests a direct link between sackung origin and post-LGM glacier thinning. However, substantial lag (>5 ka) of some sackungen in respect to glacier retreat im- plies complex relationships between sackung onset and deglaciation where retreat of glaciers acted predominantly as a preparatory, not a triggering factor during the genesis of these slope deformations. They originated either as a consequence of stress relaxation within the rock mass lasting several ka or alternatively could be triggered by climatic processes or seismicity. Indeed, a significant part of sackung activity took place during predominantly warmer and more humid periods, with some dates coinciding with the Bølling e Allerød chronozone, but especially with the onset of the Holocene and the Holocene Climatic Optimum. Earthquake triggering is less probable, as the Tatra Mts. lack significant modern and historic seismic activity and there is no geomorphic evidence of fault offsets on the Late Quaternary landforms. In concert with other recent studies, we propose that large rock slope failures in high mountains seldom react immediately to glacier withdrawal, but could display temporal delay lasting up to several millennia.
A detailed geomorphological map of the surroundings of Prasilske Lake, Bohemian Forest, Czech Rep... more A detailed geomorphological map of the surroundings of Prasilske Lake, Bohemian Forest, Czech Republic is presented. A layer of elementary forms (segments of relief nearing constant values of fundamental morphometric variables) holistically covering the whole mapped area was used as a base for mapping. Elementary forms were delineated by: i) analysis of contour lines and a DEM; ii) verification on orthophotomaps and iii) field mapping, where boundaries of each form were verified (195 elementary forms were mapped). Elementary forms were grouped according to their genesis to form geomorphologically homogenous landforms. The geomorphological map covering a 955 ha previously glaciated area is focused on morphogenesis and morphochronology. Additional maps at 1:20,000 provide information about geological characteristics and their interrelations with the main relief features. A map of the scientific reliability of landform origins presents the degrees of uncertainty in geomorphological knowledge. The mapping of elementary forms and the map of scientific reliability provide a holistic view of the mapped area (fundamental for comprehensive analysis of relief), a base for systematization of the relief and a platform for the evaluation and planning of research.
Comprehensive geomorphological and sedimentological analyses confirmed three phases of Würm glaci... more Comprehensive geomorphological and sedimentological analyses confirmed three phases of Würm glaciation in the surroundings of Prášilské Lake and Stará Jímka, in the Bohemian Forest (Šumava Mountains). Glaciations were affected by a steep east-facing slope, by plateaus on the adjacent ridges and by local geological conditions. A small valley glacier (about 2 km long and 50 m thick) occurred during the first phase. In the second phase, a glacier–rock glacier developed, probably based on remnants of the valley glacier. During the last phase glacial activity was divided into Stará Jímka and the stepped cirque of Prášilské Lake. A further shallow ( 3 m deep) lake in Stará Jímka was dammed by slope movements after deglaciation ( 14 cal. ka BP) and survived until 4 cal. ka BP. The Late Pleistocene chronology of the Bohemian Forest seems to be related more closely to the Alps than to northern Europe. In the mid-mountains of central Europe, Pleistocene glaciation decreases significantly eastward, because of increasing continentality. The presence of plateaus (deflation areas), around 1300 m altitude, across the approach of westerly winds was important for the development of glaciers in the Bohemian Forest. The termination of glaciation before the Younger Dryas is specific to the Bohemian Forest in comparison with the Vosges and Krkonoše Mountains.
Geomorphological information system – idea and option of practical implementation
An information ... more Geomorphological information system – idea and option of practical implementation An information system storing relevant geomorphological data and equipped with special analytical tools for geomorphological research can be termed a Geomorphological information system (GmIS). GmIS should maintain a complex geomorphological database, allow the user to generate specific geomorphologic information and create (carto)graphic, statistic and other outputs. An attempt to create conceptual and logical models of GmIS is presented here. The proposed GmIS is based on GIS technology with layered database structure, divided into three main parts. Adopted layers imply existing geomorphologically relevant information from non-geomorphological sources. The basic geomorphological layers represent the most frequently used immanent geomorphological data: DEM and its derivates, documentation materials, elementary forms, basins, groups of genetic landforms, morphodynamic phenomena and geomorphic network. The special geomorphological layers are based on the above and are created by processing them. From many possible two examples of geomorphological and morphostructural analysis are outlined. ESRI ArcGIS is suggested as the management system for geomorphological data.
The paper has two main aims. Firstly, to postulate a physical geodatabase model of a geomorpholog... more The paper has two main aims. Firstly, to postulate a physical geodatabase model of a geomorphological information system based on the already existing logical geodatabase model. Secondly, to define processes of geomorphological analysis based on the physical geodatabase model. The structure of the physical model follows the logical model and is divided into three parts: adopted layers (hydrology, geology, topography and others), basic layers (elementary forms, digital elevation model and derivatives, documentation materials, genetic groups of landforms, morphodynamic phenomena, basin based features and geomorphic network) and special layers (morphostructural analysis, comprehensive geomorphological analysis and so on). The geodatabase modelling methodology was used for developing the physical geodatabase model. The geomorphological analysis is based mainly on the layer of elementary forms (defined according to their morphology and morphometry) and the derived layer of morphogenetical forms (determined by genesis of landforms). The traditional methods of geomorphological mapping and also more recent concepts of geomorphological analysis were used. The concept is presented in the context of research in the surroundings of Prasilske jezero (lake) in the äumava (Mts.). ESRI products were used to carry out the project.
This study analyses selected morphometric characteristics of seven glacial cirques in the Bohemia... more This study analyses selected morphometric characteristics of seven glacial cirques in the Bohemian Forest. Firstly, a glacial system of a glacial cirque typical of the Bohemian Forest was postulated. Then, morphometric characteristics were counted and compared for components of the system (cirque floor, headwall, deflation plateau, etc.). It is probable that the total altitude (mainly the position of deflation plateaus) was an important factor for the development of glaciers. The following hypothesis was postulated based on connections between morphometric characteristics and genesis of the cirques: (1) the lengthening of the cirques occurred primarily during the cold stages of the Pleistocene depending on the size and position of the deflation plateau, (2) development of the cirques continued after the disappearance of the glaciers by other (particularly periglacial) processes, and (3) fluvial and gravitational processes reshaped the cirques during the warmer stages of the Pleistocene. Two types of ELA (equilibrium line altitude) were calculated: the TP-ELA was probably ca. 1290 m a.s.l and the TPW-ELA in ca. 1021 m a.s.l.
Sackungen represents a common mode of deep-seated rock-slope failures in alpine landscapes, but p... more Sackungen represents a common mode of deep-seated rock-slope failures in alpine landscapes, but proof of their temporal and causal relationship to extrinsic factors such as climatic changes, glacier retreat or seismic activity remains elusive. Based on the terrestrial cosmogenic nuclide (TCN) dating of 18 sackung scarps supported by one radiocarbon-dated scarp, we reconstructed the post-glacial chronology of sackungen in the Tatra Mts. (central Europe, Slovakia and Poland), the highest part of the Carpathians. The obtained ages (~15.7 e 4.3 ka) indicate that sackungen post-date the regional LGM and some of them originated soon after the glacier withdrawal from adjacent valleys. Furthermore, systematic decrease of scarp ages with their increasing altitude suggests a direct link between sackung origin and post-LGM glacier thinning. However, substantial lag (>5 ka) of some sackungen in respect to glacier retreat im- plies complex relationships between sackung onset and deglaciation where retreat of glaciers acted predominantly as a preparatory, not a triggering factor during the genesis of these slope deformations. They originated either as a consequence of stress relaxation within the rock mass lasting several ka or alternatively could be triggered by climatic processes or seismicity. Indeed, a significant part of sackung activity took place during predominantly warmer and more humid periods, with some dates coinciding with the Bølling e Allerød chronozone, but especially with the onset of the Holocene and the Holocene Climatic Optimum. Earthquake triggering is less probable, as the Tatra Mts. lack significant modern and historic seismic activity and there is no geomorphic evidence of fault offsets on the Late Quaternary landforms. In concert with other recent studies, we propose that large rock slope failures in high mountains seldom react immediately to glacier withdrawal, but could display temporal delay lasting up to several millennia.
A detailed geomorphological map of the surroundings of Prasilske Lake, Bohemian Forest, Czech Rep... more A detailed geomorphological map of the surroundings of Prasilske Lake, Bohemian Forest, Czech Republic is presented. A layer of elementary forms (segments of relief nearing constant values of fundamental morphometric variables) holistically covering the whole mapped area was used as a base for mapping. Elementary forms were delineated by: i) analysis of contour lines and a DEM; ii) verification on orthophotomaps and iii) field mapping, where boundaries of each form were verified (195 elementary forms were mapped). Elementary forms were grouped according to their genesis to form geomorphologically homogenous landforms. The geomorphological map covering a 955 ha previously glaciated area is focused on morphogenesis and morphochronology. Additional maps at 1:20,000 provide information about geological characteristics and their interrelations with the main relief features. A map of the scientific reliability of landform origins presents the degrees of uncertainty in geomorphological knowledge. The mapping of elementary forms and the map of scientific reliability provide a holistic view of the mapped area (fundamental for comprehensive analysis of relief), a base for systematization of the relief and a platform for the evaluation and planning of research.
Comprehensive geomorphological and sedimentological analyses confirmed three phases of Würm glaci... more Comprehensive geomorphological and sedimentological analyses confirmed three phases of Würm glaciation in the surroundings of Prášilské Lake and Stará Jímka, in the Bohemian Forest (Šumava Mountains). Glaciations were affected by a steep east-facing slope, by plateaus on the adjacent ridges and by local geological conditions. A small valley glacier (about 2 km long and 50 m thick) occurred during the first phase. In the second phase, a glacier–rock glacier developed, probably based on remnants of the valley glacier. During the last phase glacial activity was divided into Stará Jímka and the stepped cirque of Prášilské Lake. A further shallow ( 3 m deep) lake in Stará Jímka was dammed by slope movements after deglaciation ( 14 cal. ka BP) and survived until 4 cal. ka BP. The Late Pleistocene chronology of the Bohemian Forest seems to be related more closely to the Alps than to northern Europe. In the mid-mountains of central Europe, Pleistocene glaciation decreases significantly eastward, because of increasing continentality. The presence of plateaus (deflation areas), around 1300 m altitude, across the approach of westerly winds was important for the development of glaciers in the Bohemian Forest. The termination of glaciation before the Younger Dryas is specific to the Bohemian Forest in comparison with the Vosges and Krkonoše Mountains.
Geomorphological information system – idea and option of practical implementation
An information ... more Geomorphological information system – idea and option of practical implementation An information system storing relevant geomorphological data and equipped with special analytical tools for geomorphological research can be termed a Geomorphological information system (GmIS). GmIS should maintain a complex geomorphological database, allow the user to generate specific geomorphologic information and create (carto)graphic, statistic and other outputs. An attempt to create conceptual and logical models of GmIS is presented here. The proposed GmIS is based on GIS technology with layered database structure, divided into three main parts. Adopted layers imply existing geomorphologically relevant information from non-geomorphological sources. The basic geomorphological layers represent the most frequently used immanent geomorphological data: DEM and its derivates, documentation materials, elementary forms, basins, groups of genetic landforms, morphodynamic phenomena and geomorphic network. The special geomorphological layers are based on the above and are created by processing them. From many possible two examples of geomorphological and morphostructural analysis are outlined. ESRI ArcGIS is suggested as the management system for geomorphological data.
The paper has two main aims. Firstly, to postulate a physical geodatabase model of a geomorpholog... more The paper has two main aims. Firstly, to postulate a physical geodatabase model of a geomorphological information system based on the already existing logical geodatabase model. Secondly, to define processes of geomorphological analysis based on the physical geodatabase model. The structure of the physical model follows the logical model and is divided into three parts: adopted layers (hydrology, geology, topography and others), basic layers (elementary forms, digital elevation model and derivatives, documentation materials, genetic groups of landforms, morphodynamic phenomena, basin based features and geomorphic network) and special layers (morphostructural analysis, comprehensive geomorphological analysis and so on). The geodatabase modelling methodology was used for developing the physical geodatabase model. The geomorphological analysis is based mainly on the layer of elementary forms (defined according to their morphology and morphometry) and the derived layer of morphogenetical forms (determined by genesis of landforms). The traditional methods of geomorphological mapping and also more recent concepts of geomorphological analysis were used. The concept is presented in the context of research in the surroundings of Prasilske jezero (lake) in the äumava (Mts.). ESRI products were used to carry out the project.
This study analyses selected morphometric characteristics of seven glacial cirques in the Bohemia... more This study analyses selected morphometric characteristics of seven glacial cirques in the Bohemian Forest. Firstly, a glacial system of a glacial cirque typical of the Bohemian Forest was postulated. Then, morphometric characteristics were counted and compared for components of the system (cirque floor, headwall, deflation plateau, etc.). It is probable that the total altitude (mainly the position of deflation plateaus) was an important factor for the development of glaciers. The following hypothesis was postulated based on connections between morphometric characteristics and genesis of the cirques: (1) the lengthening of the cirques occurred primarily during the cold stages of the Pleistocene depending on the size and position of the deflation plateau, (2) development of the cirques continued after the disappearance of the glaciers by other (particularly periglacial) processes, and (3) fluvial and gravitational processes reshaped the cirques during the warmer stages of the Pleistocene. Two types of ELA (equilibrium line altitude) were calculated: the TP-ELA was probably ca. 1290 m a.s.l and the TPW-ELA in ca. 1021 m a.s.l.
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Papers by Pavel Mentlik
of their temporal and causal relationship to extrinsic factors such as climatic changes, glacier retreat or
seismic activity remains elusive. Based on the terrestrial cosmogenic nuclide (TCN) dating of 18 sackung
scarps supported by one radiocarbon-dated scarp, we reconstructed the post-glacial chronology of
sackungen in the Tatra Mts. (central Europe, Slovakia and Poland), the highest part of the Carpathians.
The obtained ages (~15.7 e 4.3 ka) indicate that sackungen post-date the regional LGM and some of them
originated soon after the glacier withdrawal from adjacent valleys. Furthermore, systematic decrease of
scarp ages with their increasing altitude suggests a direct link between sackung origin and post-LGM
glacier thinning. However, substantial lag (>5 ka) of some sackungen in respect to glacier retreat im-
plies complex relationships between sackung onset and deglaciation where retreat of glaciers acted
predominantly as a preparatory, not a triggering factor during the genesis of these slope deformations.
They originated either as a consequence of stress relaxation within the rock mass lasting several ka or
alternatively could be triggered by climatic processes or seismicity. Indeed, a significant part of sackung
activity took place during predominantly warmer and more humid periods, with some dates coinciding
with the Bølling e Allerød chronozone, but especially with the onset of the Holocene and the Holocene
Climatic Optimum. Earthquake triggering is less probable, as the Tatra Mts. lack significant modern and
historic seismic activity and there is no geomorphic evidence of fault offsets on the Late Quaternary
landforms. In concert with other recent studies, we propose that large rock slope failures in high
mountains seldom react immediately to glacier withdrawal, but could display temporal delay lasting up
to several millennia.
An information system storing relevant geomorphological data and equipped with special analytical tools for geomorphological research can be termed a Geomorphological information system (GmIS). GmIS should maintain a complex geomorphological database, allow the user to generate specific geomorphologic information and create (carto)graphic, statistic and other outputs. An attempt to create conceptual and logical models of GmIS is presented here. The proposed GmIS is based on GIS technology with layered database structure, divided into three main parts. Adopted layers imply existing geomorphologically relevant information from non-geomorphological sources. The basic geomorphological layers represent the most frequently used immanent geomorphological data: DEM and its derivates, documentation materials, elementary forms, basins, groups of genetic landforms, morphodynamic phenomena and geomorphic network. The special geomorphological layers are based on the above and are created by processing them. From many possible two examples of geomorphological and morphostructural analysis are outlined. ESRI ArcGIS is suggested as the management system for geomorphological data.
project.
of their temporal and causal relationship to extrinsic factors such as climatic changes, glacier retreat or
seismic activity remains elusive. Based on the terrestrial cosmogenic nuclide (TCN) dating of 18 sackung
scarps supported by one radiocarbon-dated scarp, we reconstructed the post-glacial chronology of
sackungen in the Tatra Mts. (central Europe, Slovakia and Poland), the highest part of the Carpathians.
The obtained ages (~15.7 e 4.3 ka) indicate that sackungen post-date the regional LGM and some of them
originated soon after the glacier withdrawal from adjacent valleys. Furthermore, systematic decrease of
scarp ages with their increasing altitude suggests a direct link between sackung origin and post-LGM
glacier thinning. However, substantial lag (>5 ka) of some sackungen in respect to glacier retreat im-
plies complex relationships between sackung onset and deglaciation where retreat of glaciers acted
predominantly as a preparatory, not a triggering factor during the genesis of these slope deformations.
They originated either as a consequence of stress relaxation within the rock mass lasting several ka or
alternatively could be triggered by climatic processes or seismicity. Indeed, a significant part of sackung
activity took place during predominantly warmer and more humid periods, with some dates coinciding
with the Bølling e Allerød chronozone, but especially with the onset of the Holocene and the Holocene
Climatic Optimum. Earthquake triggering is less probable, as the Tatra Mts. lack significant modern and
historic seismic activity and there is no geomorphic evidence of fault offsets on the Late Quaternary
landforms. In concert with other recent studies, we propose that large rock slope failures in high
mountains seldom react immediately to glacier withdrawal, but could display temporal delay lasting up
to several millennia.
An information system storing relevant geomorphological data and equipped with special analytical tools for geomorphological research can be termed a Geomorphological information system (GmIS). GmIS should maintain a complex geomorphological database, allow the user to generate specific geomorphologic information and create (carto)graphic, statistic and other outputs. An attempt to create conceptual and logical models of GmIS is presented here. The proposed GmIS is based on GIS technology with layered database structure, divided into three main parts. Adopted layers imply existing geomorphologically relevant information from non-geomorphological sources. The basic geomorphological layers represent the most frequently used immanent geomorphological data: DEM and its derivates, documentation materials, elementary forms, basins, groups of genetic landforms, morphodynamic phenomena and geomorphic network. The special geomorphological layers are based on the above and are created by processing them. From many possible two examples of geomorphological and morphostructural analysis are outlined. ESRI ArcGIS is suggested as the management system for geomorphological data.
project.