... Two exceptions are a Diploastrea coral head from Vanuatu which lived during the Younger Dryas... more ... Two exceptions are a Diploastrea coral head from Vanuatu which lived during the Younger Dryas (Burr et al., 1998) and a Goniastrea coral from Papua New Guinea which lived approximately 13,000 years ago, according to U Th dating. This subannual record (Fig. ...
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2000
The cosmic-ray flux incident upon the Earth during the late Pleistocene, 20–60 kyr B.P., was stud... more The cosmic-ray flux incident upon the Earth during the late Pleistocene, 20–60 kyr B.P., was studied by measuring the cosmogenic radionuclide 10Be from a marine sediment core at site CH88-10P on the Blake Outer Ridge. The paleointensity of the geomagnetic field for this core was determined by various methods. The variance in the concentration of 10Be in the authigenic fraction
The long-lived radionuclide 129I is well known as a useful environmental tracer. At present, the ... more The long-lived radionuclide 129I is well known as a useful environmental tracer. At present, the global 129I in surface water is about 1-2 orders of magnitude higher than pre-1990 levels. The anthropogenic 129I signal produced from industrial nuclear fuel reprocessing plants is known to be the primary source of 129I in marine surface waters of the Atlantic, and elevated 129I
An Accelerator Mass Spectrometry (AMS) facility has been operated at the University of Arizona si... more An Accelerator Mass Spectrometry (AMS) facility has been operated at the University of Arizona since 1982. This is an excellent example of a facility which has benefitted from the NSF Earth Sciences Instrumentation and Facilities Program. AMS has many applications to the fields of geochronology, geoarchaeology, paleoclimatology. A wide range of climatic, geologic and archeological records can be characterized by
129I occurs naturally in extremely low abundance via cosmic ray interactions in the atmosphere as... more 129I occurs naturally in extremely low abundance via cosmic ray interactions in the atmosphere as well as by spontaneous fission of uranium. Oceanic concentrations of 129I have risen by several orders of magnitude during the last half century largely from environmental pollution coming from several point-source nuclear fuel reprocessing plants. In the Pacific basin, much of the increase has apparently
... Two exceptions are a Diploastrea coral head from Vanuatu which lived during the Younger Dryas... more ... Two exceptions are a Diploastrea coral head from Vanuatu which lived during the Younger Dryas (Burr et al., 1998) and a Goniastrea coral from Papua New Guinea which lived approximately 13,000 years ago, according to U Th dating. This subannual record (Fig. ...
... AJ Timothy Jull Corresponding Author Contact Information , a , E-mail The Corresponding Autho... more ... AJ Timothy Jull Corresponding Author Contact Information , a , E-mail The Corresponding Author , George S. Burr a , J. Warren Beck a , Gregory WL Hodgins a , Dana L. Biddulph a , Lanny R. McHargue a and Todd E. Lange a. ...
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2000
The cosmic-ray flux incident upon the Earth during the late Pleistocene, 20–60 kyr B.P., was stud... more The cosmic-ray flux incident upon the Earth during the late Pleistocene, 20–60 kyr B.P., was studied by measuring the cosmogenic radionuclide 10Be from a marine sediment core at site CH88-10P on the Blake Outer Ridge. The paleointensity of the geomagnetic field for this core was determined by various methods. The variance in the concentration of 10Be in the authigenic fraction
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2000
Accelerator mass spectrometry (AMS) measurements of environmental 14C have been employed during t... more Accelerator mass spectrometry (AMS) measurements of environmental 14C have been employed during the past decade at the several micromole level (tens of μg carbon), but advanced research in the atmospheric and marine sciences demands still higher (μg) sensitivity, an extreme example being the determination of 14C in elemental or “black” carbon (BC) at levels of 2–10 μg per kg of
... Two exceptions are a Diploastrea coral head from Vanuatu which lived during the Younger Dryas... more ... Two exceptions are a Diploastrea coral head from Vanuatu which lived during the Younger Dryas (Burr et al., 1998) and a Goniastrea coral from Papua New Guinea which lived approximately 13,000 years ago, according to U Th dating. This subannual record (Fig. ...
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2000
The cosmic-ray flux incident upon the Earth during the late Pleistocene, 20–60 kyr B.P., was stud... more The cosmic-ray flux incident upon the Earth during the late Pleistocene, 20–60 kyr B.P., was studied by measuring the cosmogenic radionuclide 10Be from a marine sediment core at site CH88-10P on the Blake Outer Ridge. The paleointensity of the geomagnetic field for this core was determined by various methods. The variance in the concentration of 10Be in the authigenic fraction
The long-lived radionuclide 129I is well known as a useful environmental tracer. At present, the ... more The long-lived radionuclide 129I is well known as a useful environmental tracer. At present, the global 129I in surface water is about 1-2 orders of magnitude higher than pre-1990 levels. The anthropogenic 129I signal produced from industrial nuclear fuel reprocessing plants is known to be the primary source of 129I in marine surface waters of the Atlantic, and elevated 129I
An Accelerator Mass Spectrometry (AMS) facility has been operated at the University of Arizona si... more An Accelerator Mass Spectrometry (AMS) facility has been operated at the University of Arizona since 1982. This is an excellent example of a facility which has benefitted from the NSF Earth Sciences Instrumentation and Facilities Program. AMS has many applications to the fields of geochronology, geoarchaeology, paleoclimatology. A wide range of climatic, geologic and archeological records can be characterized by
129I occurs naturally in extremely low abundance via cosmic ray interactions in the atmosphere as... more 129I occurs naturally in extremely low abundance via cosmic ray interactions in the atmosphere as well as by spontaneous fission of uranium. Oceanic concentrations of 129I have risen by several orders of magnitude during the last half century largely from environmental pollution coming from several point-source nuclear fuel reprocessing plants. In the Pacific basin, much of the increase has apparently
... Two exceptions are a Diploastrea coral head from Vanuatu which lived during the Younger Dryas... more ... Two exceptions are a Diploastrea coral head from Vanuatu which lived during the Younger Dryas (Burr et al., 1998) and a Goniastrea coral from Papua New Guinea which lived approximately 13,000 years ago, according to U Th dating. This subannual record (Fig. ...
... AJ Timothy Jull Corresponding Author Contact Information , a , E-mail The Corresponding Autho... more ... AJ Timothy Jull Corresponding Author Contact Information , a , E-mail The Corresponding Author , George S. Burr a , J. Warren Beck a , Gregory WL Hodgins a , Dana L. Biddulph a , Lanny R. McHargue a and Todd E. Lange a. ...
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2000
The cosmic-ray flux incident upon the Earth during the late Pleistocene, 20–60 kyr B.P., was stud... more The cosmic-ray flux incident upon the Earth during the late Pleistocene, 20–60 kyr B.P., was studied by measuring the cosmogenic radionuclide 10Be from a marine sediment core at site CH88-10P on the Blake Outer Ridge. The paleointensity of the geomagnetic field for this core was determined by various methods. The variance in the concentration of 10Be in the authigenic fraction
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2000
Accelerator mass spectrometry (AMS) measurements of environmental 14C have been employed during t... more Accelerator mass spectrometry (AMS) measurements of environmental 14C have been employed during the past decade at the several micromole level (tens of μg carbon), but advanced research in the atmospheric and marine sciences demands still higher (μg) sensitivity, an extreme example being the determination of 14C in elemental or “black” carbon (BC) at levels of 2–10 μg per kg of
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