Deep Drill 1972. Heat Flow and Heat Production in Bermuda

1974 ◽  
Vol 11 (6) ◽  
pp. 809-818 ◽  
Author(s):  
R. D. Hyndman ◽  
G. K. Muecke ◽  
F. Aumento
Keyword(s):  
Heat Flux ◽  
Heat Flow ◽  
Heat Production ◽  
Land Surface ◽  
Gamma Ray ◽  
Gamma Ray Spectrometry ◽  
Geothermal Heat ◽  
Sea Floor ◽  
Average Value ◽  
The Mean

The geothermal heat flux determined in a borehole on Bermuda is 1.36 μcal/cm2 s (57 mW/m2). The value is corrected for the topographic effect of the Bermuda sea-mount and the difference between sea floor and land surface temperatures. Radioactive heat production in the borehole core determined by gamma-ray spectrometry has an average value of 1.45 × 10−13 cal/cm3 s (6.11 × 10−7 W/m3). Of the altered tholeiite flows and intrusive lamprophyric sheets which make up the section to 800 m, the sheets have 10 times the heat production of the flows. If the heat production attributable to the Bermuda seamount is subtracted from the measured heat flux a value of 1.26 μcal/cm2 s (53 mW/m2) is obtained which is in good agreement with the mean of surrounding sea floor measurements and with the mean for Cretaceous ocean floor. The low heat flow and the small amount of subsidence substantiates the radioactive dating data which indicates the present seamount structure was produced about 33 m.y. ago by intrusion and uplift of a much older structure.

Average annual committed effective dose and threshold consumption rate of bovine samples collected from a government owned abattoir, Ikpoba slope, Benin City, Nigeria

2020 ◽  
Vol 98 (8) ◽  
pp. 742-751
Author(s):  
K.W. Giwa ◽  
O.D. Osahon
Keyword(s):  
Consumption Rate ◽  
Gamma Ray ◽  
Absorbed Dose ◽  
The Body ◽  
Gamma Ray Spectrometry ◽  
Absorbed Dose Rate ◽  
Benin City ◽  
Average Value ◽  
The Mean ◽  
Meat Samples

The activity concentrations of 40K, 232Th, and 238U in five different organs of bovine meat commonly eaten by the Nigerian populace were measured using gamma ray spectrometry. The meat samples were collected from a Government owned abattoir at Ikpoba slope, Benin City. The essence of the study was to estimate the internal radiation dose incurred by a population due to the ingestion of radionuclides from meat consumption. The mean absorbed dose rate was 12.60 ± 1.51 nGy h−1, which is far lower than the recommended value of 55 nGy h−1. The AACED obtained in this study differs for each organ, thereby making the threshold consumption rate different, but the mean dose, 0.171 ± 0.07 mSv yr−1, is below the 0.3 mSv yr−1 reported to be the recommended average value. The mean threshold consumption rate for meat intake for the samples under study was calculated to be 107.5 ± 6.22 kg yr–1. Thus, this study has contributed to the body of knowledge and data that can lead to the formulation of regulations related to radiological healthcare in the study area.

Heat flow and surface radioactivity in the Quirke Lake Syncline near Elliot Lake, Ontario, Canada

1968 ◽  
Vol 5 (6) ◽  
pp. 1417-1428 ◽  
Author(s):  
J. H. Sass ◽  
P. G. Killeen ◽  
E. D. Mustonen
Keyword(s):  
Heat Flow ◽  
Heat Production ◽  
Gamma Ray ◽  
Average Rate ◽  
Structural Effects ◽  
Gamma Ray Spectrometer ◽  
A Value ◽  
The Mean ◽  
Data Yield ◽  
Ore Zones

Heat flow was measured in seven diamond-drilled holes, ranging in depth from 300 to 900 m, in the Quirke Lake Syncline (82° 30′ W, 46° 30′ N, mean elevation 370 m), Values for individual holes vary from 1.20 to 1.40 with a mean of 1.32 ± 0.02 μcal/cm2s, and no systematic variation was detected within the 50 km2 area studied. Radiometric measurements with a portable, three-channel, gamma-ray spectrometer show a downward concentration (stratigraphically) of Th, U, and K within the lower part of the syncline, with mean concentrations of 12.7 ppm, 3.3 ppm, and 1.9%, respectively. These data yield an average rate of heat production of 4.5 heat generation units (1 hgu = 10−13 cal/cm3s). Taking account of the ore zones, the mean heat production from the syncline is about 6 hgu. Corrections for structural effects and heat production from the ore result in a value of 1.2 for the regional heat flow. This is within the range of other shield values, although somewhat higher than the average for the Canadian Shield. The high value is readily explained if the observed mean surface radioactivity persists to a depth of 7 to 10 km.

ADDITIONAL HEAT FLOW DETERMINATIONS IN THE AREA OF MOULD BAY, ARCTIC CANADA

1966 ◽  
Vol 3 (2) ◽  
pp. 237-246 ◽  
Author(s):  
W. S. B. Paterson ◽  
L. K. Law
Keyword(s):  
Heat Flow ◽  
Canadian Arctic ◽  
The Arctic ◽  
Canadian Arctic Archipelago ◽  
General Area ◽  
Geothermal Heat ◽  
Field Methods ◽  
The Mean ◽  
Water Depths ◽  
Made In

Seven determinations of geothermal heat flow were made in the general area of southern Prince Patrick Island in the Canadian Arctic Archipelago. Measurements were made from sea ice in water depths of between 200 and 600 m. The mean heat flow for the two stations on the continental shelf in the Arctic Ocean was 0.46 ± 0.08 μcal cm−2 s−1. The mean heat flow for the five stations in the channels to the east of Mould Bay was 1.46 ± 0.16 μcal cm−2 s−1. The instrument and field methods are described. Errors due to the instrument and to the environment are discussed.

Low geothermal heat flow of the Urals fold belt — implication of low heat production, fluid circulation or palaeoclimate?

1997 ◽  
Vol 276 (1-4) ◽  
pp. 63-85 ◽  
Author(s):  
I.T. Kukkonen ◽  
I.V. Golovanova ◽  
Yu.V. Khachay ◽  
V.S. Druzhinin ◽  
A.M. Kosarev ◽  
...  
Keyword(s):  
Heat Flow ◽  
Heat Production ◽  
Fluid Circulation ◽  
Fold Belt ◽  
The Urals ◽  
Geothermal Heat

Assessment of Radiological Significance of the Wastes Generated from the Triple Super Phosphate (TSP) Fertilizer Factory, Chittagong, Bangladesh

2012 ◽  
Vol 36 (1) ◽  
pp. 79-88 ◽  
Author(s):  
MA Samad ◽  
MI Ali ◽  
D Paul ◽  
SMA Islam
Keyword(s):  
Gamma Ray ◽  
Hazard Index ◽  
Liquid Waste ◽  
Radiation Hazard ◽  
Gamma Ray Spectrometry ◽  
Radium Equivalent Activity ◽  
Average Value ◽  
Liquid Samples ◽  
Activity Concentrations ◽  
Academy Of Sciences

The activity concentration of 226Ra, 232Th and 40K was determined in solid and liquid samples collected from the TSP Fertilizer Factory, Chittagong, Bangladesh. A total of 18 samples of seven different kinds (including liquid and solid wastes) were collected and analyzed by gamma ray spectrometry technique using a high purity germanium (HPGe) detector of 40% relative efficiency. The analysis of the liquid waste samples showed that the average activity concentrations of 226Ra and 232Th were 6.26 ± 0.63 and 10.01 ± 1.39 Bq/L, respectively and no 40K was detected in any of the liquid samples. In the solid waste samples the average value of activity concentrations of 226Ra, 232Th and 40K were 187.49 ± 4.88, 70.06 ± 11.76 and 655.94 ± 110.24 Bq/kg, respectively. Considering the stored wastes as a part of the ambient environment of the factory, radium equivalent activity, radiation hazard index and external annual effective dose to the worker and public due to these wastes were also calculated and compared with world average values. DOI: http://dx.doi.org/10.3329/jbas.v36i1.10923 Journal of Bangladesh Academy of Sciences, Vol. 36, No. 1, 79-88, 2012

Analysis of Heat Flow Data–Vertical Variations of Heat Flow and Heat Producing Elements in Sediments

1975 ◽  
Vol 12 (6) ◽  
pp. 996-1005 ◽  
Author(s):  
V. M. Hamza ◽  
A. E. Beck
Keyword(s):  
Heat Flow ◽  
Heat Production ◽  
Gamma Ray ◽  
Detailed Examination ◽  
Uranium Content ◽  
Thermal Resistivity ◽  
Geochemical Reactions ◽  
Vertical Variations ◽  
Heat Flow Variations

Gamma ray spectrometric techniques have been used for the determination of uranium, thorium and potassium contents from cores selected at 3 to 4 m intervals from a 600 m deep borehole in sedimentary formations and the results compared with a similarly detailed examination of heat flow, and some physical properties, from the same borehole.The results indicate a broad positive correlation between thermal resistivity and some of the radio-element parameters and between heat flow and heat production. The heat production variations down the borehole are not quantitatively sufficient to explain the observed heat flow variations. The uranium series appears to be in radioactive equilibrium even in those sections where the uranium content is low, the porosity relatively high and the heat flow low; it is therefore concluded that the depletion of uranium is due to an ancient rather than a recent leaching process and that it is unlikely that the heat flow variations along the borehole are due to existing or recent underground waterflows. Long term geochemical reactions are now thought to be the most likely explanation of the heat flow variations.

scholarly journals Advancement toward coupling of the VAMPER permafrost model within the Earth system model <I>i</I>LOVECLIM (version 1.0): description and validation

2015 ◽  
Vol 8 (5) ◽  
pp. 1445-1460 ◽  
Author(s):  
D. C. Kitover ◽  
R. van Balen ◽  
D. M. Roche ◽  
J. Vandenberghe ◽  
H. Renssen
Keyword(s):  
Heat Flux ◽  
Land Surface ◽  
Organic Soil ◽  
Earth System Model ◽  
System Model ◽  
Earth System ◽  
Geothermal Heat ◽  
Land Surface Temperatures ◽  
Spatially Varying ◽  
Snow Thickness

Abstract. The VU Amsterdam Permafrost (VAMPER) permafrost model has been enhanced with snow thickness and active layer calculations in preparation for coupling within the iLOVECLIM Earth system model of intermediate complexity (EMIC). In addition, maps of basal heat flux and lithology were developed within ECBilt, the atmosphere component of iLOVECLIM, so that VAMPER may use spatially varying parameters of geothermal heat flux and porosity values. The enhanced VAMPER model is validated by comparing the simulated modern-day extent of permafrost thickness with observations. To perform the simulations, the VAMPER model is forced by iLOVECLIM land surface temperatures. Results show that the simulation which did not include the snow cover option overestimated the present permafrost extent. However, when the snow component is included, the simulated permafrost extent is reduced too much. In analyzing simulated permafrost depths, it was found that most of the modeled thickness values and subsurface temperatures fall within a reasonable range of the corresponding observed values. Discrepancies between simulated and observed permafrost depth distribution are due to lack of captured effects from features such as topography and organic soil layers. In addition, some discrepancy is also due to disequilibrium with the current climate, meaning that some observed permafrost is a result of colder states and therefore cannot be reproduced accurately with constant iLOVECLIM preindustrial forcings.

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