Ole Humlum - Academia.edu (original) (raw)
Papers by Ole Humlum
Geografisk Tidsskrift-danish Journal of Geography, 1995
Geografisk Tidsskrift-danish Journal of Geography, 1996
Geografisk Tidsskrift-danish Journal of Geography, 1983
Bulletin of The Geological Society of Denmark, Feb 23, 2023
Bony fishes are among the best represented macrofossils from the earliest Eocene Fur Formation, n... more Bony fishes are among the best represented macrofossils from the earliest Eocene Fur Formation, northern Denmark. The most abundant fish of the formation has never been formally described, in spite of its abundance throughout the formation, and only referred to as an 'argentinoid'. This work provides a taxonomic study of this argentinoid taxon, which is described herein as Surlykus longigracilis gen. et sp. nov. The caudal skeleton shows separated first preural and first ural centra, a unique condition within the Argentiniformes. In addition, it is characterised by having a large mouth and a single supramaxilla, which suggest that Surlykus gen. nov. occupies a basal position within the Argentiniformes, representing the sister-group to all the other lineages of this clade ([Argentinidae + Opisthoproctidae] + [Bathylagidae + Microstomatidae]), and, consequently, a stem-group Argentiniformes. Mass-mortality assemblages may indicate that Surlykus longigracilis gen. et sp. nov. formed large schools in the ancient North Sea Basin, where it probably represented the trophic nucleus of the fish communities.
Geografisk Tidsskrift-danish Journal of Geography, 1997
Geografisk Tidsskrift-danish Journal of Geography, 1996
In October 1990 an automatic meteorological station was established at the Arctic Station (69°15&... more In October 1990 an automatic meteorological station was established at the Arctic Station (69°15'N, 53°31'W), Qeqertarsuaq (Godhavn), Central West Greenland, The station register parameters each 20 min, and the parameters have been described in an earlier paper in this journal by Nielsen et al. (1995). The present paper summarises main points of the climate during 1995. Concentrational agriculture, defined as types of agriculture based on local concentration of plant nutrients, encompasses two main types: shifting cultivation and infield-outfield systems. They may ecologically be characterised by their mode of concentration: either by a vertical or a horisontal transfer (‘pumping’) of nutrients, respectively. The use of the general term ‘concentrational agriculture’ for the two forms is advocated by demonstrating that functional substitution of one by the other is possible, and by showing that the one type theoretically can be derived from the other. Historically, infield-outfield systems are supposed to ...
Geografisk Tidsskrift-danish Journal of Geography, 1984
Humlum. Ole: Altitudinal trends of talus-derived lobate rock glaciers on Disko, central West Gree... more Humlum. Ole: Altitudinal trends of talus-derived lobate rock glaciers on Disko, central West Greenland. Geografisk Tidsskrift 84: 35–39, Copenhagen. January 1984. Talus-derived lobate (TDL) rock glaciers follow the altitudinal trend of the equilibrium line (ELA) on contemporary glaciers, and based on an analysis of a cross-section, North Disko, it is suggested that the vertical distance between the zone of TDL-rock glaciers and the lowermost occurrence of tongue-shaped rock glaciers relate to the amount of precipitation.
Bulletin of The Geological Society of Denmark, Dec 31, 1980
Small-scale deformations of glaciofluvial sediments is described from a Greenland outwash plain p... more Small-scale deformations of glaciofluvial sediments is described from a Greenland outwash plain partly covered by icings (Aufeis, naleds). On the sudace these deformations takes the form of small ridges, parallel to the margin of the icings. Formation of the ridges is ascribed to processes during disintegration of icings, and the genetic term » Icing-ridge« is proposed. Icing ridges produced in a braided river environment are considered as most likely to be preserved at the base of small-scale coarsening upward sequences.
The Western Swiss Alps are located at approximately 46°N 7.5°E and cover around 3,000 km 2 of typ... more The Western Swiss Alps are located at approximately 46°N 7.5°E and cover around 3,000 km 2 of typical high-mountain terrain with a predominantly continental climate. They consist of nine south-north catchments located on the orographic left side of the Rhône River with altitudes ranging between 500 m (Rhône Valley) and 4,634 m a.s.l. (Dufourspitze). Along the suspended valleys, the vertical slope extent typically ranges between 1,250 m and more than 3,000 m a.s.l.. The periglacial belt-defined as the sparsely-vegetated portion of the mountain slope in between the tree line up to the bottom of the glaciated area-ranges from approximately from 2,300 m to 3,000 m a.s.l. and is characterized by many different Alpine geomorphological processes (Barboux et al., 2015). Moving zones related to the creep of frozen debris (e.g., rock glaciers, push-moraines) and shallow to deep-seated landslides affecting frozen as well as unfrozen debris or rocks are widespread. In the Western Swiss Alps, the lower limit of discontinuous permafrost is estimated to be at an altitude of about 2,400 m a.s.l. for north-facing slopes and 2,700 m a.s.l. for southern exposures (Lambiel and Reynard, 2003). The area encompasses about 800 active rock glaciers with typical velocities on the order of 0.1 to 2 m/yr. Among them, at least eleven rock glaciers have experienced changes in their kinematics, geometry and topography over recent decades (Delaloye et al., 2010). These features, displaying exceptionally high velocities up to 10 m/yr and often showing distinct cracks as well as significant changes at their fronts, have been identified as destabilized (Delaloye et al., 2010). When located on steep slopes, they may be the source for other mass movement such as rock falls or debris flows (Delaloye et al., 2010). The additional data used on this region consists of: © Swissimages orthoimages at 0.25 m spatial resolution; © SwissAlti3D high resolution DTM at 2 m spatial resolution (https://www.swisstopo.admin.ch; last access: 2 October 2021). A2 Southern Venosta, Italy The study area occupies the northeastern portion of Ortles-Cevedale massif in South Tyrol, Central-Eastern Italian Alps (46.5°N, 10.9°E). It extends over about 970 km 2 and includes the southern side of the lower Venosta valley, as well as five tributary valleys: Ultental (Val d'Ultimo), Martelltal (Val Martello), Laasertal (Val di Lasa), and Suldental (Val di Solda). Elevation ranges from 3,905 m a.s.l. on Mount Ortles, down to about 500 m at Southern Venosta outlet. Bedrock geology is dominated by metamorphic lithologies (chiefly paragneiss, micaschists, and orthogneiss), with granite outcropping locally in lower Martelltal, and limestones and dolostones in upper Suldental. Climate is dry, with mean annual precipitation ranging from less than 600 mm in Venosta valley floor (Schlanders station) to more than 1,200 mm in upland cirque valleys (Weissbrunn station). According to Permanet modelling (www.permanet.eu; last access: 20 June 2021) and field-based evidence, discontinuous mountain permafrost occurs above threshold elevations varying between 2,300 and 2,700 m a.s.l.,
Geografisk Tidsskrift-danish Journal of Geography, 1995
Geografisk Tidsskrift-Danish Journal of Geography, 1995
Danish Journal of Geography 95: 92–96, 1995. Three cores collected from a proglacial lake with an... more Danish Journal of Geography 95: 92–96, 1995. Three cores collected from a proglacial lake with an Axelsson corer are x-rayed. The stratification is interpreted as varves. The cores cover periods of sedimentation with a duration from 5—23 years. The average thickness of the varves vary from 1.9—20.0 mm indicating a tenfold variation in the sedimentation rate. Geografisk Tidsskrift 96: 97–104, 1995. In October 1990 a new automatic meteorological station was established at the Arctic Station, Qeqertarsuaq (Godhavn), managed by the University of Copenhagen. It is the purpose of this note to draw the attention to the existence of this meteorological station, the character of climate parameter monitored and to the environment in which the station is functioning. Examples of climate data measured during 1994 are presented, and general trends in the fluctuation of the selected parameters are annotated. Furthermore, it is mentioned how users may obtain the climate data. In the years to come we plan to publish a si...
Permafrost and Periglacial Processes, 2011
Rapport Grønlands Geologiske Undersøgelse, 1992
The application of multi-model photogrammetry to steep cliff faces is described and examples give... more The application of multi-model photogrammetry to steep cliff faces is described and examples given of the manipulation of the digitised data to produce three-dimensional terrain models, and by using other software models to estimate surface radiation balance.
HAL (Le Centre pour la Communication Scientifique Directe), 2019
Permafrost and Periglacial Processes, Oct 1, 1997
... Conductive as well as non-conductive heat transfer processes appear to be important in the ac... more ... Conductive as well as non-conductive heat transfer processes appear to be important in the active layer on both rock glacier types. ... Meteorological controls on this variation are discussed, and thus the environmental controls on rock glacier formation. ...
Geografisk Tidsskrift-danish Journal of Geography, 1978
Geografisk Tidsskrift-danish Journal of Geography, 1995
Geografisk Tidsskrift-danish Journal of Geography, 1996
Geografisk Tidsskrift-danish Journal of Geography, 1983
Bulletin of The Geological Society of Denmark, Feb 23, 2023
Bony fishes are among the best represented macrofossils from the earliest Eocene Fur Formation, n... more Bony fishes are among the best represented macrofossils from the earliest Eocene Fur Formation, northern Denmark. The most abundant fish of the formation has never been formally described, in spite of its abundance throughout the formation, and only referred to as an 'argentinoid'. This work provides a taxonomic study of this argentinoid taxon, which is described herein as Surlykus longigracilis gen. et sp. nov. The caudal skeleton shows separated first preural and first ural centra, a unique condition within the Argentiniformes. In addition, it is characterised by having a large mouth and a single supramaxilla, which suggest that Surlykus gen. nov. occupies a basal position within the Argentiniformes, representing the sister-group to all the other lineages of this clade ([Argentinidae + Opisthoproctidae] + [Bathylagidae + Microstomatidae]), and, consequently, a stem-group Argentiniformes. Mass-mortality assemblages may indicate that Surlykus longigracilis gen. et sp. nov. formed large schools in the ancient North Sea Basin, where it probably represented the trophic nucleus of the fish communities.
Geografisk Tidsskrift-danish Journal of Geography, 1997
Geografisk Tidsskrift-danish Journal of Geography, 1996
In October 1990 an automatic meteorological station was established at the Arctic Station (69°15&... more In October 1990 an automatic meteorological station was established at the Arctic Station (69°15'N, 53°31'W), Qeqertarsuaq (Godhavn), Central West Greenland, The station register parameters each 20 min, and the parameters have been described in an earlier paper in this journal by Nielsen et al. (1995). The present paper summarises main points of the climate during 1995. Concentrational agriculture, defined as types of agriculture based on local concentration of plant nutrients, encompasses two main types: shifting cultivation and infield-outfield systems. They may ecologically be characterised by their mode of concentration: either by a vertical or a horisontal transfer (‘pumping’) of nutrients, respectively. The use of the general term ‘concentrational agriculture’ for the two forms is advocated by demonstrating that functional substitution of one by the other is possible, and by showing that the one type theoretically can be derived from the other. Historically, infield-outfield systems are supposed to ...
Geografisk Tidsskrift-danish Journal of Geography, 1984
Humlum. Ole: Altitudinal trends of talus-derived lobate rock glaciers on Disko, central West Gree... more Humlum. Ole: Altitudinal trends of talus-derived lobate rock glaciers on Disko, central West Greenland. Geografisk Tidsskrift 84: 35–39, Copenhagen. January 1984. Talus-derived lobate (TDL) rock glaciers follow the altitudinal trend of the equilibrium line (ELA) on contemporary glaciers, and based on an analysis of a cross-section, North Disko, it is suggested that the vertical distance between the zone of TDL-rock glaciers and the lowermost occurrence of tongue-shaped rock glaciers relate to the amount of precipitation.
Bulletin of The Geological Society of Denmark, Dec 31, 1980
Small-scale deformations of glaciofluvial sediments is described from a Greenland outwash plain p... more Small-scale deformations of glaciofluvial sediments is described from a Greenland outwash plain partly covered by icings (Aufeis, naleds). On the sudace these deformations takes the form of small ridges, parallel to the margin of the icings. Formation of the ridges is ascribed to processes during disintegration of icings, and the genetic term » Icing-ridge« is proposed. Icing ridges produced in a braided river environment are considered as most likely to be preserved at the base of small-scale coarsening upward sequences.
The Western Swiss Alps are located at approximately 46°N 7.5°E and cover around 3,000 km 2 of typ... more The Western Swiss Alps are located at approximately 46°N 7.5°E and cover around 3,000 km 2 of typical high-mountain terrain with a predominantly continental climate. They consist of nine south-north catchments located on the orographic left side of the Rhône River with altitudes ranging between 500 m (Rhône Valley) and 4,634 m a.s.l. (Dufourspitze). Along the suspended valleys, the vertical slope extent typically ranges between 1,250 m and more than 3,000 m a.s.l.. The periglacial belt-defined as the sparsely-vegetated portion of the mountain slope in between the tree line up to the bottom of the glaciated area-ranges from approximately from 2,300 m to 3,000 m a.s.l. and is characterized by many different Alpine geomorphological processes (Barboux et al., 2015). Moving zones related to the creep of frozen debris (e.g., rock glaciers, push-moraines) and shallow to deep-seated landslides affecting frozen as well as unfrozen debris or rocks are widespread. In the Western Swiss Alps, the lower limit of discontinuous permafrost is estimated to be at an altitude of about 2,400 m a.s.l. for north-facing slopes and 2,700 m a.s.l. for southern exposures (Lambiel and Reynard, 2003). The area encompasses about 800 active rock glaciers with typical velocities on the order of 0.1 to 2 m/yr. Among them, at least eleven rock glaciers have experienced changes in their kinematics, geometry and topography over recent decades (Delaloye et al., 2010). These features, displaying exceptionally high velocities up to 10 m/yr and often showing distinct cracks as well as significant changes at their fronts, have been identified as destabilized (Delaloye et al., 2010). When located on steep slopes, they may be the source for other mass movement such as rock falls or debris flows (Delaloye et al., 2010). The additional data used on this region consists of: © Swissimages orthoimages at 0.25 m spatial resolution; © SwissAlti3D high resolution DTM at 2 m spatial resolution (https://www.swisstopo.admin.ch; last access: 2 October 2021). A2 Southern Venosta, Italy The study area occupies the northeastern portion of Ortles-Cevedale massif in South Tyrol, Central-Eastern Italian Alps (46.5°N, 10.9°E). It extends over about 970 km 2 and includes the southern side of the lower Venosta valley, as well as five tributary valleys: Ultental (Val d'Ultimo), Martelltal (Val Martello), Laasertal (Val di Lasa), and Suldental (Val di Solda). Elevation ranges from 3,905 m a.s.l. on Mount Ortles, down to about 500 m at Southern Venosta outlet. Bedrock geology is dominated by metamorphic lithologies (chiefly paragneiss, micaschists, and orthogneiss), with granite outcropping locally in lower Martelltal, and limestones and dolostones in upper Suldental. Climate is dry, with mean annual precipitation ranging from less than 600 mm in Venosta valley floor (Schlanders station) to more than 1,200 mm in upland cirque valleys (Weissbrunn station). According to Permanet modelling (www.permanet.eu; last access: 20 June 2021) and field-based evidence, discontinuous mountain permafrost occurs above threshold elevations varying between 2,300 and 2,700 m a.s.l.,
Geografisk Tidsskrift-danish Journal of Geography, 1995
Geografisk Tidsskrift-Danish Journal of Geography, 1995
Danish Journal of Geography 95: 92–96, 1995. Three cores collected from a proglacial lake with an... more Danish Journal of Geography 95: 92–96, 1995. Three cores collected from a proglacial lake with an Axelsson corer are x-rayed. The stratification is interpreted as varves. The cores cover periods of sedimentation with a duration from 5—23 years. The average thickness of the varves vary from 1.9—20.0 mm indicating a tenfold variation in the sedimentation rate. Geografisk Tidsskrift 96: 97–104, 1995. In October 1990 a new automatic meteorological station was established at the Arctic Station, Qeqertarsuaq (Godhavn), managed by the University of Copenhagen. It is the purpose of this note to draw the attention to the existence of this meteorological station, the character of climate parameter monitored and to the environment in which the station is functioning. Examples of climate data measured during 1994 are presented, and general trends in the fluctuation of the selected parameters are annotated. Furthermore, it is mentioned how users may obtain the climate data. In the years to come we plan to publish a si...
Permafrost and Periglacial Processes, 2011
Rapport Grønlands Geologiske Undersøgelse, 1992
The application of multi-model photogrammetry to steep cliff faces is described and examples give... more The application of multi-model photogrammetry to steep cliff faces is described and examples given of the manipulation of the digitised data to produce three-dimensional terrain models, and by using other software models to estimate surface radiation balance.
HAL (Le Centre pour la Communication Scientifique Directe), 2019
Permafrost and Periglacial Processes, Oct 1, 1997
... Conductive as well as non-conductive heat transfer processes appear to be important in the ac... more ... Conductive as well as non-conductive heat transfer processes appear to be important in the active layer on both rock glacier types. ... Meteorological controls on this variation are discussed, and thus the environmental controls on rock glacier formation. ...
Geografisk Tidsskrift-danish Journal of Geography, 1978