B G Mcfadgen
Biographic Data
| ID | 1150766 |
|---|---|
| NAME | B G Mcfadgen |
| GIVEN NAMES | B G |
| FAMILY NAME | Mcfadgen |
| SIGNATURE | MCFADGEN B G |
| AFFILIATIONS | Department of Conservation |
| VERIFIED | No |
| TOTAL WORKS | 9 |
| TOTAL CITATIONS | 65 |
| WORKS AS AUTHOR | 9 |
| WORKS AS EDITOR | 0 |
| FIRST PUBLICATION YEAR | 1971 |
| LATEST PUBLICATION YEAR | 2004 |
| H-INDEX | 4 |
Radiocarbon/Tree-Ring Calibration, Solar Activity, and Upwelling of Ocean Water
Least-squares fitted smooth curves to radiocarbon versus tree-ring calibration data for the period AD 1140 to 1950 are compared with climatic warming and cooling of the North Atlantic (Little Ice Age), and with recorded sunspot numbers over the period AD 1670 to 1950. Calibration curves from different parts of the globe are not identical, and appear to be determined by a combination of variable solar activity and variable oceanic upwelling of 14 …
Least-Squares Fitting Smooth Curves to Decadal Radiocarbon Calibration Data from AD 1145 to AD 1945
Smoothed curves are least-squares fitted to three sets of decadal radiocarbon calibration data from New Zealand and British Isles (AD 1725–1935) and western North America (AD 1145–1945). The curves are compared with each other and with a curve previously calculated from New Zealand data (AD 1335–1745). The smoothing procedure results in reduced standard deviations of the curves, but at the expense of time resolution. The comparison shows a variab…
Catastrophic seismic-related events and their impact on prehistoric human occupation, coastal New Zealand
The catastrophic 1855 AD Wellington earthquake is used to predict likely environmental impacts of earlier seismic events (earthquake and tsunami) that have been reported for the Cook Strait region in the period following first human settlement 700 years ago. Environmental changes around Palliser Bay in prehistoric Maori times, inferred from archaeological research, parallel those that occurred in 1855 AD. We consider that devastation caused by ea…
Tephras and New Zealand Archaeology
Radiocarbon age of the Kaharoa Tephra, a key marker for late-Holocene stratigraphy and archaeology in New Zealand
The Kaharoa eruption, the most recent rhyolitic volcanic event in New Zealand, resulted in the deposition of the compositionally distinctive Kaharoa Tephra over at least 30 000 km 2 of northern and eastern North Island. The tephra forms an isochronous marker bed for various late-Holocene stratigraphic and palaeoen vironmental studies but is particularly important for evaluating the chronology of New Zealand's notably short prehistory because it w…
Least-Squares Fitting A Smooth Curve to Radiocarbon Calibration Data
We Fourier transformed and filtered calibration curve data to compensate for the averaging effect of radiocarbon-dating sets of adjacent tree rings. A Wiener Filter was also applied to minimize the effects of the counting errors of the dates on the resulting calibration curve and to produce a least-squares curve through the data. The method is illustrated using a short 14 C-dated tree-ring sequence from New Zealand to produce a calibration curve …
Radiocarbon Calibration Curve Variations and Their Implications for the Interpretation of New Zealand Prehistory
The shape of a distribution of calibrated 14 C dates displays spurious peaks and troughs, brought about by changes in the slope of the calibration curve interacting with the spreading effect of the stochastic distribution of counting errors. The distortion results in a positive correlation between the numbers of dates per calendar year and the slopes of the calibration curves, for assemblages of archaeological dates from such widely separated are…
Calibrating New Zealand Radiocarbon Dates of Marine Shells
Radiocarbon activity of 11 modern marine shell samples from the New Zealand region is enhanced compared with the surface layers of the average world ocean. The measured enhancement, δR, is equivalent to −31 ± 13 years. On this basis, the Institute of Nuclear Sciences will now use a value of −30 years in reporting calibrated ages for marine shell samples
An Application of Stereophotogrammetry to Archaeological Recording
Radiocarbon Calibration Curve Variations and Their Implications for the Interpretation of New Zealand Prehistory
The shape of a distribution of calibrated 14 C dates displays spurious peaks and troughs, brought about by changes in the slope of the calibration curve interacting with the spreading effect of the stochastic distribution of counting errors. The distortion results in a positive correlation between the numbers of dates per calendar year and the slopes of the calibration curves, for assemblages of archaeological dates from such widely separated are…
Tephras and New Zealand Archaeology
Calibrating New Zealand Radiocarbon Dates of Marine Shells
Radiocarbon activity of 11 modern marine shell samples from the New Zealand region is enhanced compared with the surface layers of the average world ocean. The measured enhancement, δR, is equivalent to −31 ± 13 years. On this basis, the Institute of Nuclear Sciences will now use a value of −30 years in reporting calibrated ages for marine shell samples
Radiocarbon age of the Kaharoa Tephra, a key marker for late-Holocene stratigraphy and archaeology in New Zealand
The Kaharoa eruption, the most recent rhyolitic volcanic event in New Zealand, resulted in the deposition of the compositionally distinctive Kaharoa Tephra over at least 30 000 km 2 of northern and eastern North Island. The tephra forms an isochronous marker bed for various late-Holocene stratigraphic and palaeoen vironmental studies but is particularly important for evaluating the chronology of New Zealand's notably short prehistory because it w…
Least-Squares Fitting Smooth Curves to Decadal Radiocarbon Calibration Data from AD 1145 to AD 1945
Smoothed curves are least-squares fitted to three sets of decadal radiocarbon calibration data from New Zealand and British Isles (AD 1725–1935) and western North America (AD 1145–1945). The curves are compared with each other and with a curve previously calculated from New Zealand data (AD 1335–1745). The smoothing procedure results in reduced standard deviations of the curves, but at the expense of time resolution. The comparison shows a variab…
Least-Squares Fitting A Smooth Curve to Radiocarbon Calibration Data
We Fourier transformed and filtered calibration curve data to compensate for the averaging effect of radiocarbon-dating sets of adjacent tree rings. A Wiener Filter was also applied to minimize the effects of the counting errors of the dates on the resulting calibration curve and to produce a least-squares curve through the data. The method is illustrated using a short 14 C-dated tree-ring sequence from New Zealand to produce a calibration curve …
Catastrophic seismic-related events and their impact on prehistoric human occupation, coastal New Zealand
The catastrophic 1855 AD Wellington earthquake is used to predict likely environmental impacts of earlier seismic events (earthquake and tsunami) that have been reported for the Cook Strait region in the period following first human settlement 700 years ago. Environmental changes around Palliser Bay in prehistoric Maori times, inferred from archaeological research, parallel those that occurred in 1855 AD. We consider that devastation caused by ea…
Radiocarbon/Tree-Ring Calibration, Solar Activity, and Upwelling of Ocean Water
Least-squares fitted smooth curves to radiocarbon versus tree-ring calibration data for the period AD 1140 to 1950 are compared with climatic warming and cooling of the North Atlantic (Little Ice Age), and with recorded sunspot numbers over the period AD 1670 to 1950. Calibration curves from different parts of the globe are not identical, and appear to be determined by a combination of variable solar activity and variable oceanic upwelling of 14 …
An Application of Stereophotogrammetry to Archaeological Recording
An Application of Stereophotogrammetry to Archaeological Recording
Calibrating New Zealand Radiocarbon Dates of Marine Shells
Radiocarbon activity of 11 modern marine shell samples from the New Zealand region is enhanced compared with the surface layers of the average world ocean. The measured enhancement, δR, is equivalent to −31 ± 13 years. On this basis, the Institute of Nuclear Sciences will now use a value of −30 years in reporting calibrated ages for marine shell samples
Radiocarbon Calibration Curve Variations and Their Implications for the Interpretation of New Zealand Prehistory
The shape of a distribution of calibrated 14 C dates displays spurious peaks and troughs, brought about by changes in the slope of the calibration curve interacting with the spreading effect of the stochastic distribution of counting errors. The distortion results in a positive correlation between the numbers of dates per calendar year and the slopes of the calibration curves, for assemblages of archaeological dates from such widely separated are…
Least-Squares Fitting A Smooth Curve to Radiocarbon Calibration Data
We Fourier transformed and filtered calibration curve data to compensate for the averaging effect of radiocarbon-dating sets of adjacent tree rings. A Wiener Filter was also applied to minimize the effects of the counting errors of the dates on the resulting calibration curve and to produce a least-squares curve through the data. The method is illustrated using a short 14 C-dated tree-ring sequence from New Zealand to produce a calibration curve …
Radiocarbon age of the Kaharoa Tephra, a key marker for late-Holocene stratigraphy and archaeology in New Zealand
The Kaharoa eruption, the most recent rhyolitic volcanic event in New Zealand, resulted in the deposition of the compositionally distinctive Kaharoa Tephra over at least 30 000 km 2 of northern and eastern North Island. The tephra forms an isochronous marker bed for various late-Holocene stratigraphic and palaeoen vironmental studies but is particularly important for evaluating the chronology of New Zealand's notably short prehistory because it w…
Tephras and New Zealand Archaeology
Least-Squares Fitting Smooth Curves to Decadal Radiocarbon Calibration Data from AD 1145 to AD 1945
Smoothed curves are least-squares fitted to three sets of decadal radiocarbon calibration data from New Zealand and British Isles (AD 1725–1935) and western North America (AD 1145–1945). The curves are compared with each other and with a curve previously calculated from New Zealand data (AD 1335–1745). The smoothing procedure results in reduced standard deviations of the curves, but at the expense of time resolution. The comparison shows a variab…
Catastrophic seismic-related events and their impact on prehistoric human occupation, coastal New Zealand
The catastrophic 1855 AD Wellington earthquake is used to predict likely environmental impacts of earlier seismic events (earthquake and tsunami) that have been reported for the Cook Strait region in the period following first human settlement 700 years ago. Environmental changes around Palliser Bay in prehistoric Maori times, inferred from archaeological research, parallel those that occurred in 1855 AD. We consider that devastation caused by ea…
Radiocarbon/Tree-Ring Calibration, Solar Activity, and Upwelling of Ocean Water
Least-squares fitted smooth curves to radiocarbon versus tree-ring calibration data for the period AD 1140 to 1950 are compared with climatic warming and cooling of the North Atlantic (Little Ice Age), and with recorded sunspot numbers over the period AD 1670 to 1950. Calibration curves from different parts of the globe are not identical, and appear to be determined by a combination of variable solar activity and variable oceanic upwelling of 14 …
Geology (8 works) · Archaeology and ancient environmental studies (7 works) · Geology and Paleoclimatology Research (7 works) · Radiocarbon dating (7 works) · Archaeology (6 works) · Geography (6 works) · Pacific and Southeast Asian Studies (6 works) · Paleontology (6 works) · Calibration (4 works) · Prehistory (4 works)