MATTI SEPPÄLÄ
Datos Biográficos
| ID | 5777036 |
|---|---|
| NOMBRE | MATTI SEPPÄLÄ |
| NOMBRES | MATTI |
| APELLIDO | SEPPÄLÄ |
| FIRMA | SEPPÄLÄ M |
| AFILIACIONES | University of Helsinki |
| ORCID | 0000-0003-2966-6749 |
| VERIFICADO | Sí |
| TOTAL DE OBRAS | 7 |
| TOTAL DE CITAS | 3 |
| OBRAS COMO AUTOR | 7 |
| OBRAS COMO EDITOR | 0 |
| PRIMER AÑO DE PUBLICACIÓN | 1980 |
| AÑO MÁS RECIENTE DE PUBLICACIÓN | 2013 |
| ÍNDICE H | 1 |
Holocene environmental change in subarctic aeolian dune fields
Sand dune stratigraphy, radiocarbon-dated charcoal layers, palaeosol development and luminescence dating are used to reconstruct the Holocene environmental history of the dune fields in Finnish Lapland since deglaciation in the early Holocene (~10,900–10,200 cal. BP). After rapid formation and stabilisation of parabolic dunes and the immigration of Scots pine ( Pinus sylvestris), forest fires are inferred to have played a key role in triggering e…
Synthesis of studies of palsa formation underlining the importance of local environmental and physical characteristics
This review presents a synthesis of four decades of palsa studies based on field experiments and observations mainly in Fennoscandia, as well as laboratory measurements. Palsas are peat-covered mounds with a permanently frozen core; in Finnish Lapland, they range from 0.5 to 7 m in height and from 2 to 150 m in diameter. These small landforms are characteristic of the southern margin of the discontinuous permafrost zone. Palsa formation requires …
Stratigraphy, age and formation of peaty earth hummocks (pounus), Finnish Lapland
Detailed investigations of peaty earth hummocks called pounus were carried out in northemmost Finnish Lapland in the vicinity of the Kevo Subarctic Research Station. Pounus are complex, often vegetated, cryogenic mounds formed partly of peat. Some have a core of mineral soil or several large stones, or just one frost-heaved boulder covered by peat. They belong to the same group of earth hummocks as thufur and non-sorted circles. The typology of p…
Unsatisfactory field data in a calibration model for inferring past temperatures from chironomid assemblages in northern Fennoscandia
Olander et al. (1999) used single temperature measurements of surface water to represent mean July temperatures of lake waters in Lapland. It is emphasized that this is not an appropriate basis for calibration of temperatures indicated by chironomid assemblages and to draw conclusions about past air temperatures. Air temperatures at the study sites were estimated and calculated yet the role of variations in topography has been omitted. The parame…
Summit peats (‘peat cakes’) on the fells of Finnish Lapland
Peat deposits of area up to 50 m 2 and thickness of 10-50 cm on fell summits at 370-622 m a.s.1. in northern Finland have been mapped, analysed and dated. These summit 'peat cakes' are most frequent in northwestern Inari Lapland, in a relatively continental climate and close to the Arctic Ocean. It seems that the most important local factor for their development are irregularities in microtopography, which collect drift snow and shelter plants fr…
Palsarnas periodiska avsmältning i Finska Lappland
Seppälä, Matti: Palsarnas periodiska avsmältning i Finska Lappland. Geografisk Tidsskrift 82: 39–44. København, 1982 Seasonal thawing of paisas in Finnish Lapland. The study investigates the thicknesses of the active layer and the temporal local and regional differences in thawing of paisas in northernmost Finland. The study cover 17 palsabogs. Thermal gradients are measured, and the effect of surface cracks and vegetation is discussed
Stratigraphy of a Silt-cored Palsa, Atlin Region, British Columbia, Canada
Palsas in the Fourth of July Creek valley, B.C., Canada are round- or oval-shaped single hummocks with cores of silty permafrost. Their height ranges from 0.5 to 3 m. The top layer of the studied palsa is only 7 cm peat. In the frozen silt core are found segregated ice lenses up to 15 cm thick. The 0.006-0.02 mm size fraction of the core material of the palsa constitutes 55%. Carbon fourteen datings of the organic material of two different layers…
Holocene environmental change in subarctic aeolian dune fields
Sand dune stratigraphy, radiocarbon-dated charcoal layers, palaeosol development and luminescence dating are used to reconstruct the Holocene environmental history of the dune fields in Finnish Lapland since deglaciation in the early Holocene (~10,900–10,200 cal. BP). After rapid formation and stabilisation of parabolic dunes and the immigration of Scots pine ( Pinus sylvestris), forest fires are inferred to have played a key role in triggering e…
Unsatisfactory field data in a calibration model for inferring past temperatures from chironomid assemblages in northern Fennoscandia
Olander et al. (1999) used single temperature measurements of surface water to represent mean July temperatures of lake waters in Lapland. It is emphasized that this is not an appropriate basis for calibration of temperatures indicated by chironomid assemblages and to draw conclusions about past air temperatures. Air temperatures at the study sites were estimated and calculated yet the role of variations in topography has been omitted. The parame…
Summit peats (‘peat cakes’) on the fells of Finnish Lapland
Peat deposits of area up to 50 m 2 and thickness of 10-50 cm on fell summits at 370-622 m a.s.1. in northern Finland have been mapped, analysed and dated. These summit 'peat cakes' are most frequent in northwestern Inari Lapland, in a relatively continental climate and close to the Arctic Ocean. It seems that the most important local factor for their development are irregularities in microtopography, which collect drift snow and shelter plants fr…
Stratigraphy of a Silt-cored Palsa, Atlin Region, British Columbia, Canada
Palsas in the Fourth of July Creek valley, B.C., Canada are round- or oval-shaped single hummocks with cores of silty permafrost. Their height ranges from 0.5 to 3 m. The top layer of the studied palsa is only 7 cm peat. In the frozen silt core are found segregated ice lenses up to 15 cm thick. The 0.006-0.02 mm size fraction of the core material of the palsa constitutes 55%. Carbon fourteen datings of the organic material of two different layers…
Palsarnas periodiska avsmältning i Finska Lappland
Seppälä, Matti: Palsarnas periodiska avsmältning i Finska Lappland. Geografisk Tidsskrift 82: 39–44. København, 1982 Seasonal thawing of paisas in Finnish Lapland. The study investigates the thicknesses of the active layer and the temporal local and regional differences in thawing of paisas in northernmost Finland. The study cover 17 palsabogs. Thermal gradients are measured, and the effect of surface cracks and vegetation is discussed
Summit peats (‘peat cakes’) on the fells of Finnish Lapland
Peat deposits of area up to 50 m 2 and thickness of 10-50 cm on fell summits at 370-622 m a.s.1. in northern Finland have been mapped, analysed and dated. These summit 'peat cakes' are most frequent in northwestern Inari Lapland, in a relatively continental climate and close to the Arctic Ocean. It seems that the most important local factor for their development are irregularities in microtopography, which collect drift snow and shelter plants fr…
Unsatisfactory field data in a calibration model for inferring past temperatures from chironomid assemblages in northern Fennoscandia
Olander et al. (1999) used single temperature measurements of surface water to represent mean July temperatures of lake waters in Lapland. It is emphasized that this is not an appropriate basis for calibration of temperatures indicated by chironomid assemblages and to draw conclusions about past air temperatures. Air temperatures at the study sites were estimated and calculated yet the role of variations in topography has been omitted. The parame…
Stratigraphy, age and formation of peaty earth hummocks (pounus), Finnish Lapland
Detailed investigations of peaty earth hummocks called pounus were carried out in northemmost Finnish Lapland in the vicinity of the Kevo Subarctic Research Station. Pounus are complex, often vegetated, cryogenic mounds formed partly of peat. Some have a core of mineral soil or several large stones, or just one frost-heaved boulder covered by peat. They belong to the same group of earth hummocks as thufur and non-sorted circles. The typology of p…
Synthesis of studies of palsa formation underlining the importance of local environmental and physical characteristics
This review presents a synthesis of four decades of palsa studies based on field experiments and observations mainly in Fennoscandia, as well as laboratory measurements. Palsas are peat-covered mounds with a permanently frozen core; in Finnish Lapland, they range from 0.5 to 7 m in height and from 2 to 150 m in diameter. These small landforms are characteristic of the southern margin of the discontinuous permafrost zone. Palsa formation requires …
Holocene environmental change in subarctic aeolian dune fields
Sand dune stratigraphy, radiocarbon-dated charcoal layers, palaeosol development and luminescence dating are used to reconstruct the Holocene environmental history of the dune fields in Finnish Lapland since deglaciation in the early Holocene (~10,900–10,200 cal. BP). After rapid formation and stabilisation of parabolic dunes and the immigration of Scots pine ( Pinus sylvestris), forest fires are inferred to have played a key role in triggering e…
Physical geography (7 obras) · Geography (6 obras) · Geology (6 obras) · Geology and Paleoclimatology Research (5 obras) · Geomorphology (5 obras) · Climate change and permafrost (4 obras) · Oceanography (4 obras) · Peat (4 obras) · Archaeology (3 obras) · Geology (3 obras)