Wibjörn Karlén
Dados Biográficos
| ID | 6016997 |
|---|---|
| NOME | Wibjörn Karlén |
| PRENOMES | Wibjörn |
| SOBRENOME | Karlén |
| ASSINATURA | KARLEN W |
| AFILIAÇÕES | Stockholm University |
| VERIFICADO | Não |
| TOTAL DE OBRAS | 21 |
| TOTAL DE CITAÇÕES | 49 |
| TOTAL COMO AUTOR | 21 |
| TOTAL COMO EDITOR | 0 |
| PRIMEIRO ANO DE PUBLICAÇÃO | 1973 |
| ANO MAIS RECENTE DE PUBLICAÇÃO | 2011 |
| ÍNDICE H | 5 |
The Schmidt hammer as a Holocene calibrated-age dating technique
Most recent developments of Schmidt-hammer exposure-age dating (SHD) as a calibrated-age dating tool have been limited by the use of locations at two age control points. This has necessitated: (1) making assumptions about a linear R-value—age relationship; and (2) basing predictions of age errors only on R-value variance at the two age control points. This paper analyses 9900 R-values obtained from multiple-age control points on a sequence of gla…
Recent Changes in the Climate
Humanity has always lived under the threat of disasters such as famine. Now that these threats have diminished considerably in the West, it seems like people need a new scare that can be shared, thereby having a uniting effect. The possible impact of an increased atmospheric greenhouse gas concentration seems to have taken over this role. However, new dating techniques and numerous new studies have now added information that can bring about a ree…
Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data
Recent Global Warming
Recent Global Warming
Holocene climate variability
Although the dramatic climate disruptions of the last glacial period have received considerable attention, relatively little has been directed toward climate variability in the Holocene (11,500 cal yr B.P. to the present). Examination of ?50 globally distributed paleoclimate records reveals as many as six periods of significant rapid climate change during the time periods 9000"8000, 6000"5000, 4200"3800, 3500"2500, 1200"1000, and 600"150 cal yr B…
A 7400-year tree-ring chronology in northern Swedish Lapland
Tree-ring widths from 880 living, dry dead, and subfossil northern Swedish pines (Pinus syl vestris L.) have been assembled into a continuous and precisely dated chronology (the Torneträsk chronology) covering the period 5407 BC to ad 1997. Biological trends in the data were removed with autoregressive standardization (ARS) to emphasize year-to-year variability, and with regional curve stan dardization (RCS) to emphasize variability on timescales…
Holocene climatic change in Swedish Lapland inferred from an oxygen-isotope record of lacustrine biogenic silica
Holocene climatic variability was studied in a 9500-year lake-sediment sequence from the Abisko region in Swedish Lapland, using the oxygen-isotope ratio in diatom biogenic silica (d 18 O si ). Oxygen-and hydrogen-isotope ratios of waters from the Abisko area suggest that in this region the evaporative flux is small and the isotopic composition of most lakes reflects that of the local precipitation. The hydrological setting of the region and sens…
Global Temperature Forced by Solar Irradiation and Greenhouse Gases
Global Temperature Forced by Solar Irradiation and Greenhouse Gases
A 3000-year high-resolution stalagmitebased record of palaeoclimate for northeastern South Africa
High-resolution stable isotope variations and growth structure analyses of the last three millennia of a 6600-year stalagmite record at Cold Air Cave, Makapansgat Valley, South Africa, are presented. Growth layers, which are measurable over the last 250 years, are shown to be annual. The correlation between the width of growth layers and precipitation is strongly positive. Changes inδ 18 O andδ 13 C are positively correlated and inversely correla…
Interpretation of the glacio lacustrine record in northern Sweden
Interpretation of the glaciolacustrine record in northern Sweden: a comment on Snowball and Sandgren
On solar forcing of Holocene climate
The focus of this study is the possible correlation between changes in the climate of Scandinavian and changes in solar irradiation. Reliable information about Holocene climatic change in Sweden and Norway is currently available from two main sources: the 14 C dating of pine wood retrieved from above the present pine-tree limit and studies of glacier variations based on proglacial lacustrine sediments and on moraines. The reconstructed alpine tre…
Paleoclimatic Significance of the Stable Isotopic Composition and Petrology of a Late Pleistocene Stalagmite from Botswana
High-resolution δ 18 O and δ 13 C analyses of a stalagmite from Lobatse II Cave reveal late Pleistocene environmental changes in Botswana. Large shifts in δ 18 O and δ 13 C are observed between two main periods of deposition. The first period, between 51,000 and 43,000 yr B.P., was warm and humid and may have been associated with some C 3 vegetation. The second period, between 27,000 and 21,000 yr B.P., had temperatures approximately 2°C lower, a…
Fennoscandian summers from ad 500
A 1,400-year tree-ring record of summer temperatures in Fennoscandia
Global Ice-Sheet System Interlocked by Sea Level
Denton and Hughes (1983, Quaternary Research 20, 125–144) postulated that sea level linked a global ice-sheet system with both terrestrial and grounded marine components during late Quaternary ice ages. Summer temperature changes near Northern Hemisphere melting margins initiated sea-level fluctuations that controlled marine components in both polar hemispheres. It was further proposed that variations of this ice-sheet system amplified and transm…
Deglaciation Dates from Northern Swedish Lappland
Holocene Glacial and Tree-Line Variations in the White River Valley and Skolai Pass, Alaska and Yukon Territory
Complex glacier and tree-line fluctuations in the White River valley on the northern flank of the St. Elias and Wrangell Mountains in southern Alaska and Yukon Territory are recognized by detailed moraine maps and drift stratigraphy, and are dated by dendrochronology, lichenometry, 14 C ages, and stratigraphic relations of drift to the eastern (1230 14 C yr BP) and northern (1980 14 C yr BP) lobes of the White River Ash. The results show two majo…
Remnants of Viking Age Tundra in Spitsbergen and Northern Scandinavia
Holocene Climatic Variations—Their Pattern and Possible Cause
In the northeastern St. Elias Mountains in southern Yukon Territory and Alaska, C 14 -dated fluctuations of 14 glacier termini show two major intervals of Holocene glacier expansion, the older dating from 3300-2400 calendar yr BP and the younger corresponding to the Little Ice Age of the last several centuries. Both were about equivalent in magnitude. In addition, a less-extensive and short-lived advance occurred about 1250-1050 calendar yr BP (A…
A 7400-year tree-ring chronology in northern Swedish Lapland
Tree-ring widths from 880 living, dry dead, and subfossil northern Swedish pines (Pinus syl vestris L.) have been assembled into a continuous and precisely dated chronology (the Torneträsk chronology) covering the period 5407 BC to ad 1997. Biological trends in the data were removed with autoregressive standardization (ARS) to emphasize year-to-year variability, and with regional curve stan dardization (RCS) to emphasize variability on timescales…
A 3000-year high-resolution stalagmitebased record of palaeoclimate for northeastern South Africa
High-resolution stable isotope variations and growth structure analyses of the last three millennia of a 6600-year stalagmite record at Cold Air Cave, Makapansgat Valley, South Africa, are presented. Growth layers, which are measurable over the last 250 years, are shown to be annual. The correlation between the width of growth layers and precipitation is strongly positive. Changes inδ 18 O andδ 13 C are positively correlated and inversely correla…
On solar forcing of Holocene climate
The focus of this study is the possible correlation between changes in the climate of Scandinavian and changes in solar irradiation. Reliable information about Holocene climatic change in Sweden and Norway is currently available from two main sources: the 14 C dating of pine wood retrieved from above the present pine-tree limit and studies of glacier variations based on proglacial lacustrine sediments and on moraines. The reconstructed alpine tre…
The Schmidt hammer as a Holocene calibrated-age dating technique
Most recent developments of Schmidt-hammer exposure-age dating (SHD) as a calibrated-age dating tool have been limited by the use of locations at two age control points. This has necessitated: (1) making assumptions about a linear R-value—age relationship; and (2) basing predictions of age errors only on R-value variance at the two age control points. This paper analyses 9900 R-values obtained from multiple-age control points on a sequence of gla…
Holocene climatic change in Swedish Lapland inferred from an oxygen-isotope record of lacustrine biogenic silica
Holocene climatic variability was studied in a 9500-year lake-sediment sequence from the Abisko region in Swedish Lapland, using the oxygen-isotope ratio in diatom biogenic silica (d 18 O si ). Oxygen-and hydrogen-isotope ratios of waters from the Abisko area suggest that in this region the evaporative flux is small and the isotopic composition of most lakes reflects that of the local precipitation. The hydrological setting of the region and sens…
Holocene Climatic Variations—Their Pattern and Possible Cause
In the northeastern St. Elias Mountains in southern Yukon Territory and Alaska, C 14 -dated fluctuations of 14 glacier termini show two major intervals of Holocene glacier expansion, the older dating from 3300-2400 calendar yr BP and the younger corresponding to the Little Ice Age of the last several centuries. Both were about equivalent in magnitude. In addition, a less-extensive and short-lived advance occurred about 1250-1050 calendar yr BP (A…
Remnants of Viking Age Tundra in Spitsbergen and Northern Scandinavia
Holocene Glacial and Tree-Line Variations in the White River Valley and Skolai Pass, Alaska and Yukon Territory
Complex glacier and tree-line fluctuations in the White River valley on the northern flank of the St. Elias and Wrangell Mountains in southern Alaska and Yukon Territory are recognized by detailed moraine maps and drift stratigraphy, and are dated by dendrochronology, lichenometry, 14 C ages, and stratigraphic relations of drift to the eastern (1230 14 C yr BP) and northern (1980 14 C yr BP) lobes of the White River Ash. The results show two majo…
Deglaciation Dates from Northern Swedish Lappland
Global Ice-Sheet System Interlocked by Sea Level
Denton and Hughes (1983, Quaternary Research 20, 125–144) postulated that sea level linked a global ice-sheet system with both terrestrial and grounded marine components during late Quaternary ice ages. Summer temperature changes near Northern Hemisphere melting margins initiated sea-level fluctuations that controlled marine components in both polar hemispheres. It was further proposed that variations of this ice-sheet system amplified and transm…
A 1,400-year tree-ring record of summer temperatures in Fennoscandia
Fennoscandian summers from ad 500
Paleoclimatic Significance of the Stable Isotopic Composition and Petrology of a Late Pleistocene Stalagmite from Botswana
High-resolution δ 18 O and δ 13 C analyses of a stalagmite from Lobatse II Cave reveal late Pleistocene environmental changes in Botswana. Large shifts in δ 18 O and δ 13 C are observed between two main periods of deposition. The first period, between 51,000 and 43,000 yr B.P., was warm and humid and may have been associated with some C 3 vegetation. The second period, between 27,000 and 21,000 yr B.P., had temperatures approximately 2°C lower, a…
On solar forcing of Holocene climate
The focus of this study is the possible correlation between changes in the climate of Scandinavian and changes in solar irradiation. Reliable information about Holocene climatic change in Sweden and Norway is currently available from two main sources: the 14 C dating of pine wood retrieved from above the present pine-tree limit and studies of glacier variations based on proglacial lacustrine sediments and on moraines. The reconstructed alpine tre…
Interpretation of the glacio lacustrine record in northern Sweden
Interpretation of the glaciolacustrine record in northern Sweden: a comment on Snowball and Sandgren
A 3000-year high-resolution stalagmitebased record of palaeoclimate for northeastern South Africa
High-resolution stable isotope variations and growth structure analyses of the last three millennia of a 6600-year stalagmite record at Cold Air Cave, Makapansgat Valley, South Africa, are presented. Growth layers, which are measurable over the last 250 years, are shown to be annual. The correlation between the width of growth layers and precipitation is strongly positive. Changes inδ 18 O andδ 13 C are positively correlated and inversely correla…
Holocene climatic change in Swedish Lapland inferred from an oxygen-isotope record of lacustrine biogenic silica
Holocene climatic variability was studied in a 9500-year lake-sediment sequence from the Abisko region in Swedish Lapland, using the oxygen-isotope ratio in diatom biogenic silica (d 18 O si ). Oxygen-and hydrogen-isotope ratios of waters from the Abisko area suggest that in this region the evaporative flux is small and the isotopic composition of most lakes reflects that of the local precipitation. The hydrological setting of the region and sens…
Global Temperature Forced by Solar Irradiation and Greenhouse Gases
Global Temperature Forced by Solar Irradiation and Greenhouse Gases
A 7400-year tree-ring chronology in northern Swedish Lapland
Tree-ring widths from 880 living, dry dead, and subfossil northern Swedish pines (Pinus syl vestris L.) have been assembled into a continuous and precisely dated chronology (the Torneträsk chronology) covering the period 5407 BC to ad 1997. Biological trends in the data were removed with autoregressive standardization (ARS) to emphasize year-to-year variability, and with regional curve stan dardization (RCS) to emphasize variability on timescales…
Holocene climate variability
Although the dramatic climate disruptions of the last glacial period have received considerable attention, relatively little has been directed toward climate variability in the Holocene (11,500 cal yr B.P. to the present). Examination of ?50 globally distributed paleoclimate records reveals as many as six periods of significant rapid climate change during the time periods 9000"8000, 6000"5000, 4200"3800, 3500"2500, 1200"1000, and 600"150 cal yr B…
Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data
Recent Global Warming
Recent Global Warming
Recent Changes in the Climate
Humanity has always lived under the threat of disasters such as famine. Now that these threats have diminished considerably in the West, it seems like people need a new scare that can be shared, thereby having a uniting effect. The possible impact of an increased atmospheric greenhouse gas concentration seems to have taken over this role. However, new dating techniques and numerous new studies have now added information that can bring about a ree…
The Schmidt hammer as a Holocene calibrated-age dating technique
Most recent developments of Schmidt-hammer exposure-age dating (SHD) as a calibrated-age dating tool have been limited by the use of locations at two age control points. This has necessitated: (1) making assumptions about a linear R-value—age relationship; and (2) basing predictions of age errors only on R-value variance at the two age control points. This paper analyses 9900 R-values obtained from multiple-age control points on a sequence of gla…
Geology and Paleoclimatology Research (17 obras) · Geology (15 obras) · Climate change (14 obras) · Geography (14 obras) · Physical geography (14 obras) · Climatology (12 obras) · Oceanography (10 obras) · Archaeology (9 obras) · Geology (9 obras) · Holocene (9 obras)