Barbara Wohlfarth
Biographic Data
| ID | 5599238 |
|---|---|
| NAME | Barbara Wohlfarth |
| GIVEN NAMES | Barbara |
| FAMILY NAME | Wohlfarth |
| SIGNATURE | WOHLFARTH B |
| AFFILIATIONS | Stockholm University |
| ORCID | 0000-0003-0374-1368 |
| VERIFIED | Yes |
| TOTAL WORKS | 18 |
| TOTAL CITATIONS | 42 |
| AUTHOR COUNT | 18 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1995 |
| LATEST PUBLICATION YEAR | 2017 |
| H-INDEX | 3 |
Societal response to monsoonal fluctuations in NE Thailand during the demise of Angkor Civilisation
This paper investigates the possible social responses to changes in the strength of the southwest monsoon in northeastern Thailand during the currency of the Angkor civilisation. These assessments are based on hydrogen and carbon isotope records of leaf waxes (δD wax and δ 13 C wax ) from a 2000-year-long wetland sequence of Pa Kho in northeastern Thailand, a region that formed the northern boundary of the Angkor Kingdom. Our data indicate anthro…
Human adaptation to mid- to late-Holocene climate change in Northeast Thailand
This article integrates palaeoenvironmental and archaeological sequences covering the mid- to late-Holocene in Northeast Thailand. The former reveal the fluctuating intensity of the Asian summer monsoon, leading to periods of higher moisture availability with intervals of relative aridity. The latter are founded on a series of new radiocarbon determinations that provide a basic chronological framework, from the initial Neolithic settlements by ri…
A Late Glacial paleolake record from an up-dammed river valley in northern Transylvania, Romania
Lake Kumphawapi revisited – The complex climatic and environmental record of a tropical wetland in NE Thailand
Kumphawapi, which is Thailand’s largest natural freshwater lake, contains a >10,000-year-long climatic and environmental archive. New data sets (stratigraphy, chronology, hydrogen isotopes, plant macrofossil and charcoal records) for two sedimentary sequences are here combined with earlier multi-proxy studies to provide a comprehensive reconstruction of past climatic and environmental changes for Northeast Thailand. Gradually higher moisture avai…
High‐resolution X‐ray fluorescence core scanning analysis of Les Echets (France) sedimentary sequence
The Les Echets sediment sequence has recently been the subject of a high‐resolution, multi‐proxy study which revealed shifts in lake productivity linked to Greenland stadials and interstadials over the last 40 ka (Wohlfarth et al. , 2008 . Rapid ecosystem response to abrupt climate changes during the last glacial period in western Europe, 40–16 ka. Geology 36 : 407–410). Here we present new elemental data for this sequence as acquired using an X‐…
The Last Glacial Maximum
The Melting Is in the Details Global sea level rises and falls as ice sheets and glaciers melt and grow, providing an integrated picture of the changes in ice volume but little information about how much individual ice fields are contributing to those variations. Knowing the regional structure of ice variability during glaciations and deglaciations will clarify the mechanisms of the glacial cycle. Clark et al. (p. 710 ) compiled and analyzed more…
Cryptotephra sedimentation processes within two lacustrine sequences from west central Sweden
Distal tephra horizons, particularly within lacustrine sequences, are increasingly being used as time-synchronous marker horizons within palaeoclimatic and palaeoenvironmental investigations. As sedimentary features marking the presence of these so-called cryptotephras are absent to the naked eye, it is of some importance that the stratigraphic position representing primary airfall, and likewise the timing of the volcanic event, is accurately and…
Palaeolimnological and sedimentary responses to Holocene forest retreat in the Scandes Mountains, west-central Sweden
A suite of analyses was performed on sediments accumulated during the last 10 700 years in Lake Spaime, a small, hydrologically open water body in the modem alpine tundra zone of the Scandes Mountains, west-central Sweden. The study aimed to evaluate (1) the nature of climate changes that forced the late-Holocene lowering of altitudinal tree limit in the region, the timing of which is known from prior studies based on radiocarbon dating of subfos…
Unstable early-Holocene climatic and environmental conditions in northwestern Russia derived from a multidisciplinary study of a lake-sediment sequence from Pichozero, southeastern Russian Karelia
A sediment core from Lake Pichozero (6146'; N, 3725'; E 118 m a.s.l.) provides information on the environmental and climatic conditions in southeastern Russian Karelia during the Lateglacial and early Holocene (12 800-9300 cal. BP). The chronology of the sequence is constrainied by varve counting and AMS 14 C measurement of terrestrial plant macrofossils. Multiproxy analyses (magnetic susceptibility, grain size, TOC, TN, TS, Rock Eval, pollen and…
Extending the limits of the Borrobol Tephra to Scandinavia and detection of new early Holocene tephras
Analyses of two infilled lakes in Blekinge, southeast Sweden, indicate the presence of at least three tephra horizons of Termination 1 and early Holocene age. Geochemical analyses confirm the presence of the Borrobol Tephra, the Askja Tephra (10,000 14 C yr B.P.), and one previously unreported tephra of Icelandic origin. Extending the limits of the Borrobol Tephra to Scandinavia illustrates that this ash is far more widespread than previously rea…
Late-Glacial and Early Holocene Environmental and Climatic Change at Lake Tambichozero, Southeastern Russian Karelia
High-resolution lithostratigraphy, mineral magnetic, carbon, pollen, and macrofossil analyses, and accelerator mass spectrometry 14 C measurements were performed in the study of a sediment sequence from Lake Tambichozero, southeastern Russian Karelia, to reconstruct late-glacial and early Holocene aquatic and terrestrial environmental changes. The lake formed ca. 14,000 cal yr B.P. and the area around the lake was subsequently colonized by arctic…
The First Dated Eemian Lacustrine Deposit in Romania
A complex interglacial sequence of lacustrine sediments has been found near the village of Turbuta in NW Romania. Mollusk, plant macrofossil, and pollen analyses reflect climatic and environmental changes around the last interglacial climatic optimum. U-Th TIMS dating of snails strongly indicates an Eemian age of the organic sediments.
AMS Radiocarbon Measurements from the Swedish Varved Clays
The Swedish varve chronology, or Swedish Time Scale, is an annual chronology based upon the successive correlation of more than 1000 varve-thickness diagrams. The Late Glacial-Early Holocene varved clays were deposited as glaciolacustrine sediments in the Baltic Sea during the recession of the Scandinavian ice sheet. Formation of varved clays continued throughout the Holocene and is still going on in the estuary of River ångermanälven in northern…
Timing of the Last-Interglacial High Sea Level on the Seychelles Islands, Indian Ocean
Corals from the Seychelles Islands, Indian Ocean, occur mainly as small coralline algae–vermetid remnants found in cavities adhering to the rock surface, and they rarely attain more than 2 m 2 in area. Samples of Goniastrea and Porites from elevations between 1.7 and 6 m above present mean sea level were dated by TIMS 238 U– 234 U– 230 Th techniques. The ages from well-preserved corals lie between 131,000 and 122,000 yr B.P., in agreement with mo…
The climatic significance of clastic varves in the Ångermanälven Estuary, northern Sweden, AD 1860 to 1950
Multiple regression analyses were applied to decipher the correlation between monthly discharge, precipitation and temperature records and annual varve-thickness data from river Ångermanälven north-central Sweden between 1860 and 1950. Over the whole 90-year period we found generally a strong correlation between spring/summer precipitation and annual varve thickness. However, there are clear indications that precipitation during the months of Jan…
Synchronized Terrestrial Atmospheric Deglacial Records Around the North Atlantic
On the basis of synchronization of three carbon-14 ( 14 C)-dated lacustrine sequences from Sweden with tree ring and ice core records, the absolute age of the Younger Dryas-Preboreal climatic shift was determined to be 11,450 to 11,390 ± 80 years before the present. A 150-year-long cooling in the early Preboreal, associated with rising Δ 14 C values, is evident in all records and indicates an ocean ventilation change. This cooling is similar to e…
C AMS measurements from the Late Weichselian part of the Swedish Time Scale
The Swedish Time Scale
The Swedish Time Scale (STS) is a ca. 13,300-yr-long varve chronology that has been established for the Swedish east coast from >1000 overlapping clay-varve diagrams. We describe the present state of the STS and illustrate the application of this worldwide unique varve chronology for AMS radiocarbon measurements. The results are compared to other 14 C-dated calendar-year chronologies: dendrochronology, laminated lake sediments and U/Th. Our data …
Human adaptation to mid- to late-Holocene climate change in Northeast Thailand
This article integrates palaeoenvironmental and archaeological sequences covering the mid- to late-Holocene in Northeast Thailand. The former reveal the fluctuating intensity of the Asian summer monsoon, leading to periods of higher moisture availability with intervals of relative aridity. The latter are founded on a series of new radiocarbon determinations that provide a basic chronological framework, from the initial Neolithic settlements by ri…
Cryptotephra sedimentation processes within two lacustrine sequences from west central Sweden
Distal tephra horizons, particularly within lacustrine sequences, are increasingly being used as time-synchronous marker horizons within palaeoclimatic and palaeoenvironmental investigations. As sedimentary features marking the presence of these so-called cryptotephras are absent to the naked eye, it is of some importance that the stratigraphic position representing primary airfall, and likewise the timing of the volcanic event, is accurately and…
The Swedish Time Scale
The Swedish Time Scale (STS) is a ca. 13,300-yr-long varve chronology that has been established for the Swedish east coast from >1000 overlapping clay-varve diagrams. We describe the present state of the STS and illustrate the application of this worldwide unique varve chronology for AMS radiocarbon measurements. The results are compared to other 14 C-dated calendar-year chronologies: dendrochronology, laminated lake sediments and U/Th. Our data …
Societal response to monsoonal fluctuations in NE Thailand during the demise of Angkor Civilisation
This paper investigates the possible social responses to changes in the strength of the southwest monsoon in northeastern Thailand during the currency of the Angkor civilisation. These assessments are based on hydrogen and carbon isotope records of leaf waxes (δD wax and δ 13 C wax ) from a 2000-year-long wetland sequence of Pa Kho in northeastern Thailand, a region that formed the northern boundary of the Angkor Kingdom. Our data indicate anthro…
AMS Radiocarbon Measurements from the Swedish Varved Clays
The Swedish varve chronology, or Swedish Time Scale, is an annual chronology based upon the successive correlation of more than 1000 varve-thickness diagrams. The Late Glacial-Early Holocene varved clays were deposited as glaciolacustrine sediments in the Baltic Sea during the recession of the Scandinavian ice sheet. Formation of varved clays continued throughout the Holocene and is still going on in the estuary of River ångermanälven in northern…
Lake Kumphawapi revisited – The complex climatic and environmental record of a tropical wetland in NE Thailand
Kumphawapi, which is Thailand’s largest natural freshwater lake, contains a >10,000-year-long climatic and environmental archive. New data sets (stratigraphy, chronology, hydrogen isotopes, plant macrofossil and charcoal records) for two sedimentary sequences are here combined with earlier multi-proxy studies to provide a comprehensive reconstruction of past climatic and environmental changes for Northeast Thailand. Gradually higher moisture avai…
Unstable early-Holocene climatic and environmental conditions in northwestern Russia derived from a multidisciplinary study of a lake-sediment sequence from Pichozero, southeastern Russian Karelia
A sediment core from Lake Pichozero (6146'; N, 3725'; E 118 m a.s.l.) provides information on the environmental and climatic conditions in southeastern Russian Karelia during the Lateglacial and early Holocene (12 800-9300 cal. BP). The chronology of the sequence is constrainied by varve counting and AMS 14 C measurement of terrestrial plant macrofossils. Multiproxy analyses (magnetic susceptibility, grain size, TOC, TN, TS, Rock Eval, pollen and…
C AMS measurements from the Late Weichselian part of the Swedish Time Scale
The Swedish Time Scale
The Swedish Time Scale (STS) is a ca. 13,300-yr-long varve chronology that has been established for the Swedish east coast from >1000 overlapping clay-varve diagrams. We describe the present state of the STS and illustrate the application of this worldwide unique varve chronology for AMS radiocarbon measurements. The results are compared to other 14 C-dated calendar-year chronologies: dendrochronology, laminated lake sediments and U/Th. Our data …
Synchronized Terrestrial Atmospheric Deglacial Records Around the North Atlantic
On the basis of synchronization of three carbon-14 ( 14 C)-dated lacustrine sequences from Sweden with tree ring and ice core records, the absolute age of the Younger Dryas-Preboreal climatic shift was determined to be 11,450 to 11,390 ± 80 years before the present. A 150-year-long cooling in the early Preboreal, associated with rising Δ 14 C values, is evident in all records and indicates an ocean ventilation change. This cooling is similar to e…
The climatic significance of clastic varves in the Ångermanälven Estuary, northern Sweden, AD 1860 to 1950
Multiple regression analyses were applied to decipher the correlation between monthly discharge, precipitation and temperature records and annual varve-thickness data from river Ångermanälven north-central Sweden between 1860 and 1950. Over the whole 90-year period we found generally a strong correlation between spring/summer precipitation and annual varve thickness. However, there are clear indications that precipitation during the months of Jan…
Timing of the Last-Interglacial High Sea Level on the Seychelles Islands, Indian Ocean
Corals from the Seychelles Islands, Indian Ocean, occur mainly as small coralline algae–vermetid remnants found in cavities adhering to the rock surface, and they rarely attain more than 2 m 2 in area. Samples of Goniastrea and Porites from elevations between 1.7 and 6 m above present mean sea level were dated by TIMS 238 U– 234 U– 230 Th techniques. The ages from well-preserved corals lie between 131,000 and 122,000 yr B.P., in agreement with mo…
AMS Radiocarbon Measurements from the Swedish Varved Clays
The Swedish varve chronology, or Swedish Time Scale, is an annual chronology based upon the successive correlation of more than 1000 varve-thickness diagrams. The Late Glacial-Early Holocene varved clays were deposited as glaciolacustrine sediments in the Baltic Sea during the recession of the Scandinavian ice sheet. Formation of varved clays continued throughout the Holocene and is still going on in the estuary of River ångermanälven in northern…
The First Dated Eemian Lacustrine Deposit in Romania
A complex interglacial sequence of lacustrine sediments has been found near the village of Turbuta in NW Romania. Mollusk, plant macrofossil, and pollen analyses reflect climatic and environmental changes around the last interglacial climatic optimum. U-Th TIMS dating of snails strongly indicates an Eemian age of the organic sediments.
Late-Glacial and Early Holocene Environmental and Climatic Change at Lake Tambichozero, Southeastern Russian Karelia
High-resolution lithostratigraphy, mineral magnetic, carbon, pollen, and macrofossil analyses, and accelerator mass spectrometry 14 C measurements were performed in the study of a sediment sequence from Lake Tambichozero, southeastern Russian Karelia, to reconstruct late-glacial and early Holocene aquatic and terrestrial environmental changes. The lake formed ca. 14,000 cal yr B.P. and the area around the lake was subsequently colonized by arctic…
Extending the limits of the Borrobol Tephra to Scandinavia and detection of new early Holocene tephras
Analyses of two infilled lakes in Blekinge, southeast Sweden, indicate the presence of at least three tephra horizons of Termination 1 and early Holocene age. Geochemical analyses confirm the presence of the Borrobol Tephra, the Askja Tephra (10,000 14 C yr B.P.), and one previously unreported tephra of Icelandic origin. Extending the limits of the Borrobol Tephra to Scandinavia illustrates that this ash is far more widespread than previously rea…
Palaeolimnological and sedimentary responses to Holocene forest retreat in the Scandes Mountains, west-central Sweden
A suite of analyses was performed on sediments accumulated during the last 10 700 years in Lake Spaime, a small, hydrologically open water body in the modem alpine tundra zone of the Scandes Mountains, west-central Sweden. The study aimed to evaluate (1) the nature of climate changes that forced the late-Holocene lowering of altitudinal tree limit in the region, the timing of which is known from prior studies based on radiocarbon dating of subfos…
Unstable early-Holocene climatic and environmental conditions in northwestern Russia derived from a multidisciplinary study of a lake-sediment sequence from Pichozero, southeastern Russian Karelia
A sediment core from Lake Pichozero (6146'; N, 3725'; E 118 m a.s.l.) provides information on the environmental and climatic conditions in southeastern Russian Karelia during the Lateglacial and early Holocene (12 800-9300 cal. BP). The chronology of the sequence is constrainied by varve counting and AMS 14 C measurement of terrestrial plant macrofossils. Multiproxy analyses (magnetic susceptibility, grain size, TOC, TN, TS, Rock Eval, pollen and…
Cryptotephra sedimentation processes within two lacustrine sequences from west central Sweden
Distal tephra horizons, particularly within lacustrine sequences, are increasingly being used as time-synchronous marker horizons within palaeoclimatic and palaeoenvironmental investigations. As sedimentary features marking the presence of these so-called cryptotephras are absent to the naked eye, it is of some importance that the stratigraphic position representing primary airfall, and likewise the timing of the volcanic event, is accurately and…
The Last Glacial Maximum
The Melting Is in the Details Global sea level rises and falls as ice sheets and glaciers melt and grow, providing an integrated picture of the changes in ice volume but little information about how much individual ice fields are contributing to those variations. Knowing the regional structure of ice variability during glaciations and deglaciations will clarify the mechanisms of the glacial cycle. Clark et al. (p. 710 ) compiled and analyzed more…
High‐resolution X‐ray fluorescence core scanning analysis of Les Echets (France) sedimentary sequence
The Les Echets sediment sequence has recently been the subject of a high‐resolution, multi‐proxy study which revealed shifts in lake productivity linked to Greenland stadials and interstadials over the last 40 ka (Wohlfarth et al. , 2008 . Rapid ecosystem response to abrupt climate changes during the last glacial period in western Europe, 40–16 ka. Geology 36 : 407–410). Here we present new elemental data for this sequence as acquired using an X‐…
A Late Glacial paleolake record from an up-dammed river valley in northern Transylvania, Romania
Lake Kumphawapi revisited – The complex climatic and environmental record of a tropical wetland in NE Thailand
Kumphawapi, which is Thailand’s largest natural freshwater lake, contains a >10,000-year-long climatic and environmental archive. New data sets (stratigraphy, chronology, hydrogen isotopes, plant macrofossil and charcoal records) for two sedimentary sequences are here combined with earlier multi-proxy studies to provide a comprehensive reconstruction of past climatic and environmental changes for Northeast Thailand. Gradually higher moisture avai…
Human adaptation to mid- to late-Holocene climate change in Northeast Thailand
This article integrates palaeoenvironmental and archaeological sequences covering the mid- to late-Holocene in Northeast Thailand. The former reveal the fluctuating intensity of the Asian summer monsoon, leading to periods of higher moisture availability with intervals of relative aridity. The latter are founded on a series of new radiocarbon determinations that provide a basic chronological framework, from the initial Neolithic settlements by ri…
Societal response to monsoonal fluctuations in NE Thailand during the demise of Angkor Civilisation
This paper investigates the possible social responses to changes in the strength of the southwest monsoon in northeastern Thailand during the currency of the Angkor civilisation. These assessments are based on hydrogen and carbon isotope records of leaf waxes (δD wax and δ 13 C wax ) from a 2000-year-long wetland sequence of Pa Kho in northeastern Thailand, a region that formed the northern boundary of the Angkor Kingdom. Our data indicate anthro…
Geology and Paleoclimatology Research (17 works) · Geography (16 works) · Physical geography (16 works) · Holocene (13 works) · Geology (11 works) · Paleontology (9 works) · Radiocarbon dating (9 works) · Macrofossil (8 works) · Pleistocene-Era Hominins and Archaeology (8 works) · Archaeology and ancient environmental studies (7 works)