Torbjörn E Törnqvist
Biographic Data
| ID | 5599473 |
|---|---|
| NAME | Torbjörn E Törnqvist |
| GIVEN NAMES | Torbjörn E |
| FAMILY NAME | Törnqvist |
| SIGNATURE | TÖRNQVIST T E |
| AFFILIATIONS | Tulane University |
| ORCID | 0000-0002-1563-1716 |
| VERIFIED | Yes |
| TOTAL WORKS | 9 |
| TOTAL CITATIONS | 34 |
| WORKS AS AUTHOR | 9 |
| WORKS AS EDITOR | 0 |
| FIRST PUBLICATION YEAR | 1991 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 3 |
Climate-driven depopulation and adaptation realities in America’s coastal ground zero
A river delta in transition
Fluvial responses to climate and sea‐level change
Fluvial landforms and deposits provide one of the most readily studied Quaternary continental records, and alluvial strata represent an important component in most ancient continental interior and continental margin successions. Moreover, studies of the long‐term dynamics of fluvial systems and their responses to external or ‘allogenic' controls, can play important roles in research concerning both global change and sequence‐stratigraphy, as well…
Improving Methodology for High-Resolution Reconstruction of Sea-Level Rise and Neotectonics by Paleoecological Analysis and AMS 14 C Dating of Basal Peats
Sea-level research in several submerging coastal regions has traditionally been based on 14 C dating of basal peats that overlie a compaction-free substratum and can be related to paleo-(ground)water levels. Provided that an unequivocal relationship between (ground)water level and sea level can be assumed, this approach contains two sources of uncertainty: (1) the paleoenvironmental interpretation of samples is usually based on inherently inaccur…
Paleoecological Studies of a Holocene Lacustrine Record from the Kangerlussuaq (Søndre Strømfjord) Region of West Greenland
A lacustrine sediment record from the Kangerlussuaq region, West Greenland, has resulted in a pollen, macrofossil, and sediment stratigraphy that encompasses the last 5000 14 C yr. Deglaciation of the area and subsequent development of a nearby floodplain occurred before 5000 yr B.P. Since that time eolian sand and silt deposition appear to have been continuous, with a significant increase ca. 1000 14 C yr B.P. Pollen analysis shows little change…
Calibration of 14 C Histograms
The interpretation of 14 C histograms is complicated by the non-linearity of the 14 C time scale in terms of calendar years, which may result in clustering of 14 C ages in certain time intervals unrelated to the (geologic or archaeologic) phenomenon of interest. One can calibrate 14 C histograms for such distortions using two basic approaches. The KORHIS method constructs a 14 C histogram before calibration is performed by means of a correction f…
How Smooth Should Curves Be for Calibrating Radiocarbon Ages
We show that smoothed versions of the high-resolution calibration curve should be used when 14 C ages are calibrated with large (> ∼30 14 C yr) measurement errors (represented by standard deviation δ m ) or are mixtures of elements of variable age (natural sample error with standard deviation δ n ). The degree of smoothing should agree with the standard deviation of total sample error, δ t , the square root of the quadratic sum of δ m and δ n . H…
Accurate Dating of Organic Deposits by AMS 14 C Measurement of Macrofossils
We made a comparative study of AMS 14 C ages of organic deposits (minerotrophic peats and gyttjas) and macrofossils in order to evaluate the magnitude of a number of sources of error that may be present in bulk sediment samples. The consistency of 14 C ages found for coexisting macrofossils suggests that they are unlikely to record disturbances. Some of our gyttja samples yielded an age 0.2–0.6 ka 14 C years too old due to hardwater effect. We al…
The role of scale in the biostratigraphy and chronostratigraphy of the Holocene Series in The Netherlands
In this paper the diachronous nature of some chronostratigraphic boundaries which are derived from the standard biostratigraphic subdivision of the Holocene Series in The Netherlands is discussed. Diachroneity is illustrated with an example from the fluvial area in The Netherlands and with relevant results of recent palynological research in other parts of the country. In explaining the time-transgressive nature of pollen zones it is argued that …
Accurate Dating of Organic Deposits by AMS 14 C Measurement of Macrofossils
We made a comparative study of AMS 14 C ages of organic deposits (minerotrophic peats and gyttjas) and macrofossils in order to evaluate the magnitude of a number of sources of error that may be present in bulk sediment samples. The consistency of 14 C ages found for coexisting macrofossils suggests that they are unlikely to record disturbances. Some of our gyttja samples yielded an age 0.2–0.6 ka 14 C years too old due to hardwater effect. We al…
Calibration of 14 C Histograms
The interpretation of 14 C histograms is complicated by the non-linearity of the 14 C time scale in terms of calendar years, which may result in clustering of 14 C ages in certain time intervals unrelated to the (geologic or archaeologic) phenomenon of interest. One can calibrate 14 C histograms for such distortions using two basic approaches. The KORHIS method constructs a 14 C histogram before calibration is performed by means of a correction f…
How Smooth Should Curves Be for Calibrating Radiocarbon Ages
We show that smoothed versions of the high-resolution calibration curve should be used when 14 C ages are calibrated with large (> ∼30 14 C yr) measurement errors (represented by standard deviation δ m ) or are mixtures of elements of variable age (natural sample error with standard deviation δ n ). The degree of smoothing should agree with the standard deviation of total sample error, δ t , the square root of the quadratic sum of δ m and δ n . H…
The role of scale in the biostratigraphy and chronostratigraphy of the Holocene Series in The Netherlands
In this paper the diachronous nature of some chronostratigraphic boundaries which are derived from the standard biostratigraphic subdivision of the Holocene Series in The Netherlands is discussed. Diachroneity is illustrated with an example from the fluvial area in The Netherlands and with relevant results of recent palynological research in other parts of the country. In explaining the time-transgressive nature of pollen zones it is argued that …
Accurate Dating of Organic Deposits by AMS 14 C Measurement of Macrofossils
We made a comparative study of AMS 14 C ages of organic deposits (minerotrophic peats and gyttjas) and macrofossils in order to evaluate the magnitude of a number of sources of error that may be present in bulk sediment samples. The consistency of 14 C ages found for coexisting macrofossils suggests that they are unlikely to record disturbances. Some of our gyttja samples yielded an age 0.2–0.6 ka 14 C years too old due to hardwater effect. We al…
Calibration of 14 C Histograms
The interpretation of 14 C histograms is complicated by the non-linearity of the 14 C time scale in terms of calendar years, which may result in clustering of 14 C ages in certain time intervals unrelated to the (geologic or archaeologic) phenomenon of interest. One can calibrate 14 C histograms for such distortions using two basic approaches. The KORHIS method constructs a 14 C histogram before calibration is performed by means of a correction f…
How Smooth Should Curves Be for Calibrating Radiocarbon Ages
We show that smoothed versions of the high-resolution calibration curve should be used when 14 C ages are calibrated with large (> ∼30 14 C yr) measurement errors (represented by standard deviation δ m ) or are mixtures of elements of variable age (natural sample error with standard deviation δ n ). The degree of smoothing should agree with the standard deviation of total sample error, δ t , the square root of the quadratic sum of δ m and δ n . H…
Paleoecological Studies of a Holocene Lacustrine Record from the Kangerlussuaq (Søndre Strømfjord) Region of West Greenland
A lacustrine sediment record from the Kangerlussuaq region, West Greenland, has resulted in a pollen, macrofossil, and sediment stratigraphy that encompasses the last 5000 14 C yr. Deglaciation of the area and subsequent development of a nearby floodplain occurred before 5000 yr B.P. Since that time eolian sand and silt deposition appear to have been continuous, with a significant increase ca. 1000 14 C yr B.P. Pollen analysis shows little change…
Improving Methodology for High-Resolution Reconstruction of Sea-Level Rise and Neotectonics by Paleoecological Analysis and AMS 14 C Dating of Basal Peats
Sea-level research in several submerging coastal regions has traditionally been based on 14 C dating of basal peats that overlie a compaction-free substratum and can be related to paleo-(ground)water levels. Provided that an unequivocal relationship between (ground)water level and sea level can be assumed, this approach contains two sources of uncertainty: (1) the paleoenvironmental interpretation of samples is usually based on inherently inaccur…
Fluvial responses to climate and sea‐level change
Fluvial landforms and deposits provide one of the most readily studied Quaternary continental records, and alluvial strata represent an important component in most ancient continental interior and continental margin successions. Moreover, studies of the long‐term dynamics of fluvial systems and their responses to external or ‘allogenic' controls, can play important roles in research concerning both global change and sequence‐stratigraphy, as well…
A river delta in transition
Climate-driven depopulation and adaptation realities in America’s coastal ground zero
Geology and Paleoclimatology Research (8 works) · Geological formations and processes (4 works) · Geology (4 works) · Physical geography (4 works) · Radiocarbon dating (4 works) · Climate change (3 works) · Geography (3 works) · Geology (3 works) · Holocene (3 works) · Macrofossil (3 works)