Heat flow measurements under some lakes in the Superior Province of the Canadian Shield

1979 ◽  
Vol 16 (10) ◽  
pp. 1951-1964 ◽  
Author(s):  
R. G. Allis ◽  
G. D. Garland
Keyword(s):  
Heat Flow ◽  
High Heat ◽  
Flow Measurements ◽  
Average Heat ◽  
Heat Flows ◽  
Climatic Variations ◽  
Northwestern Ontario ◽  
Flow Heat ◽  
Lateral Heat ◽  
Made In

Six heat flow values have been obtained from measurements made in the sediments of thermally-stable lakes in four major structural belts of northwestern Ontario. Each heat flow is the average of measurements from 3–6 neighbouring lakes. Corrections for the thermal history, lateral heat flow, sedimentation, and refraction effects have been applied. High heat flows which were measured in the Quetico gneiss superbelt (77 mW/m2) and on the Indian Lake intrusion in the Wabigoon superbelt (64 mW/m2) are related to above-average heat productivities at these locations, but the extent in depth of the sources is shown to be very different in the two cases. The consistency of the lake results with borehole measurements, on a heat flow – heat productivity plot, strongly suggests that the former are not perturbed by recent climatic variations.

A discussion on the structure and evolution of the Red Sea and the nature of the Red Sea, Gulf of Aden and Ethiopia rift junction - A review of Red Sea heat flow

1970 ◽  
Vol 267 (1181) ◽  
pp. 191-203 ◽  
Keyword(s):  
Heat Flow ◽  
Red Sea ◽  
High Heat ◽  
Temperature Measurements ◽  
High Heat Flow ◽  
Flow Measurements ◽  
The World ◽  
Brine Pools ◽  
Deep Exploration ◽  
Made In

There are now twelve heat flow measurements in the Red Sea made with heat flow probes from survey ships and several sets of temperature measurements made in deep exploration boreholes. The oceanic measurements are in water depths ranging from 0.94 to 2.70 km and all but one of these measurements give values significantly higher than the world mode of 46 mW m -2 (1.1 ). They include the world record high oceanic measurement of more than 3307 mW m -2 (79.0) in the neighbourhood of the hot brine pools. These measurements show that the deep axial trough of the Red Sea is associated with high heat flow, the values being similar to those found in the mid-Indian Ocean rift, the mid-Atlantic rift and over the crest of the East Pacific rise. It is of considerable interest to see if there is also high heat flow over the Red Sea margins and the main purpose of this paper is to examine temperature data from deep exploration boreholes. The boreholes are drilled mainly in rock salt, sandstones and shales. A discussion is given of the thermal conductivities assumed for these rocks. The boreholes have depths of up to 4 km and in some cases the temperature measurements enable an estimate to be made of the heat flow. These are also found to be high. The significance of the high heat flow to ideas concerning the structure and evolution of the Red Sea is discussed.

Some new measurements of heat flow in the Superior Province of the Canadian Shield

1987 ◽  
Vol 24 (7) ◽  
pp. 1486-1489 ◽  
Author(s):  
Malcolm Drury ◽  
Alan Taylor
Keyword(s):  
Standard Deviation ◽  
Heat Flow ◽  
Canadian Shield ◽  
Superior Province ◽  
Flow Measurements ◽  
Radiogenic Heat ◽  
Radiogenic Heat Production ◽  
Climatic Variations ◽  
The Mean ◽  
A Site

Borehole heat-flow measurements are reported from six new sites in the Superior Province of the Canadian Shield. Values adjusted for glaciation effects, but not for Holocene climatic variations, range from 42 to 56 mW/m2. When these new values are combined with 21 previously published borehole values the mean is 42 mW/m2 with a standard deviation of 11 mW/m2. The data for a site on the Lac du Bonnet batholith suggest that the batholith has a thin veneer, less than 3 km, of rock of high radiogenic heat production at the surface.

scholarly journals Terrestrial Heat Flow in New Zealand

2021 ◽  
Author(s):  
◽  
Om Prakash Pandey
Keyword(s):  
New Zealand ◽  
Heat Flow ◽  
Heat Generation ◽  
Plate Tectonics ◽  
High Heat ◽  
The North ◽  
Rock Types ◽  
Flow Heat ◽  
Geophysical Anomalies ◽  
First Time

<p>In this regional heat flow study of New Zealand temperatures have been measured in available boreholes using a specially constructed thermistor probe, and existing temperature information has been incorporated from various sources including oil prospecting boreholes. Thermal conductivity has been measured in the laboratory on 581 samples. Newly determined values of heat flow are given for 105 locations; values for the South Island are here presented for the first time. Most of the heat flow values have been grouped in eight regions based on the level of heat flow. This classification can be related to the occurrence of certain surface manifestations and geophysical anomalies, and to regional plate tectonics. High heat flow in three regions is consistent with melting conditions being reached at depths between 35km and 45km. These are the Taranaki Region, the West Coast Region and the Great South Basin. The average regional heat flow for these regions varies from 86.4 mW/m2 to 110.7 mW/m2. Much lower heat flow is obtained in the Hikurangi and Marlborough-Canterbury Regions; these may possibly be interconnected. Elsewhere the heat flow is low to normal with isolated highs. The broad distribution of heat flow in the North Island is typical for an active subduction region. Radioactive heat generation has been measured on rock types from various localities, and large variations have been found. The heat flow - heat generation relationship has been studied for 42 sites. A linear relationship is found only in the Taranaki and Hikurangi Regions. Temperature calculations show large differences in the deep-seated temperature distribution beneath New Zealand, and this has also been reflected in the distribution of "reduced heat flow". Temperature and heat flow can be correlated with upper mantle inhomogeneity. The inferred variation of radioactive heat generation with depth has been studied for areas beneath the Western Canterbury Region. A mean heat generation of 1.56 plus-minus .07 muW/m3 has been found in a sequence which has been inferred to occur between 17km and 30km in depth under the region; this is very much higher than the usually adopted values for the lower crust. Normal heat flow observed in the Western Cook Strait Region, and the existence of good seismic wave transmission beneath the same region, can be attributed to crustal and lithospheric thickening. The relevance of present study to petroleum occurrences has been examined and it is found that in areas of proven hydrocarbon potential the heat flow is high.</p>

scholarly journals Terrestrial Heat Flow in New Zealand

2021 ◽  
Author(s):  
◽  
Om Prakash Pandey
Keyword(s):  
New Zealand ◽  
Heat Flow ◽  
Heat Generation ◽  
Plate Tectonics ◽  
High Heat ◽  
The North ◽  
Rock Types ◽  
Flow Heat ◽  
Geophysical Anomalies ◽  
First Time

<p>In this regional heat flow study of New Zealand temperatures have been measured in available boreholes using a specially constructed thermistor probe, and existing temperature information has been incorporated from various sources including oil prospecting boreholes. Thermal conductivity has been measured in the laboratory on 581 samples. Newly determined values of heat flow are given for 105 locations; values for the South Island are here presented for the first time. Most of the heat flow values have been grouped in eight regions based on the level of heat flow. This classification can be related to the occurrence of certain surface manifestations and geophysical anomalies, and to regional plate tectonics. High heat flow in three regions is consistent with melting conditions being reached at depths between 35km and 45km. These are the Taranaki Region, the West Coast Region and the Great South Basin. The average regional heat flow for these regions varies from 86.4 mW/m2 to 110.7 mW/m2. Much lower heat flow is obtained in the Hikurangi and Marlborough-Canterbury Regions; these may possibly be interconnected. Elsewhere the heat flow is low to normal with isolated highs. The broad distribution of heat flow in the North Island is typical for an active subduction region. Radioactive heat generation has been measured on rock types from various localities, and large variations have been found. The heat flow - heat generation relationship has been studied for 42 sites. A linear relationship is found only in the Taranaki and Hikurangi Regions. Temperature calculations show large differences in the deep-seated temperature distribution beneath New Zealand, and this has also been reflected in the distribution of "reduced heat flow". Temperature and heat flow can be correlated with upper mantle inhomogeneity. The inferred variation of radioactive heat generation with depth has been studied for areas beneath the Western Canterbury Region. A mean heat generation of 1.56 plus-minus .07 muW/m3 has been found in a sequence which has been inferred to occur between 17km and 30km in depth under the region; this is very much higher than the usually adopted values for the lower crust. Normal heat flow observed in the Western Cook Strait Region, and the existence of good seismic wave transmission beneath the same region, can be attributed to crustal and lithospheric thickening. The relevance of present study to petroleum occurrences has been examined and it is found that in areas of proven hydrocarbon potential the heat flow is high.</p>

scholarly journals Crustal heat flow measurements in western Anatolia from borehole equilibrium temperatures

2014 ◽  
Vol 6 (1) ◽  
pp. 403-426 ◽  
Author(s):  
K. Erkan
Keyword(s):  
Heat Flow ◽  
Flow Analysis ◽  
Aegean Sea ◽  
High Heat ◽  
Quality Data ◽  
Western Anatolia ◽  
High Heat Flow ◽  
Flow Measurements ◽  
Water Wells ◽  
Direct Measurements

Abstract. Results of a crustal heat flow analysis in western Anatolia based on borehole equilibrium temperatures and rock thermal conductivity data are reported. The dataset comprises 113 borehole sites that were collected in Southern Marmara and Aegean regions of Turkey in 1995–1999. The measurements are from abandoned water wells with depths of 100–150 m. Data were first classed in terms of quality, and the low quality data, including data showing effects of hydrologic disturbances on temperatures, were eliminated. For the remaining 34 sites, one meter resolution temperature-depth curves were carefully analyzed for determination of the background geothermal gradients, and any effects of terrain topography and intra-borehole fluid flow were corrected when necessary. Thermal conductivities were determined either by direct measurements on representative surface outcrop or estimated from the borehole lithologic records. The calculated heat flow values are 85–90 mW m−2 in the northern and central parts of the Menderes horst-graben system. Within the system, the highest heat flow values (> 100 mW m−2) are observed in the northeastern part of Gediz Graben, near Kula active volcanic center. The calculated heat flow values are also in agreement with the results of studies on the maximum depth of seismicity in the region. In the Menderes horst-graben system, surface heat flow is expected to show significant variations as a result of active sedimentation and thermal refraction in grabens, and active erosion on horst detachment zones. High heat flow values (90–100 mW m−2) are also observed in the peninsular (western) part of Çanakkale province. The heat flow anomaly here may be an extension of the high heat flow zone previously observed in the northern Aegean Sea. Moderate heat flow values (60–70 mW m−2) are observed in eastern part of Çanakkale and central part of Balıkesir provinces.

Surface heat flow measurements at the Puhimau hot spot

Geophysics ◽  
1985 ◽  
Vol 50 (7) ◽  
pp. 1108-1112 ◽  
Author(s):  
J. C. Dunn ◽  
H. C. Hardee
Keyword(s):  
Heat Flow ◽  
Hot Spot ◽  
Local Area ◽  
High Heat ◽  
High Heat Flux ◽  
Flow Sensors ◽  
Flow Measurements ◽  
Geophysical Technique ◽  
Geophysical Measurements ◽  
High Output

The Puhimau hot spot, on Kilauea Volcano, Hawaii, was thermally mapped using new high‐output thermopile heat flow sensors. This thermal geophysical technique allows rapid measurement of surficial heat flow, especially in regions of high heat flux where shallow burial depths can be used. Heat flow measurements ranged from 200 to [Formula: see text] over the central portion of the Puhimau hot spot. Analysis of the heat flow data combined with other geophysical measurements suggests that the Puhimau hot spot could be caused by a shallow and perhaps still molten body of magma beneath the local area. These geophysical measurements, along with a proposed shallow scientific drillhole, can provide valuable evaluation of geophysical techniques for locating magma bodies in the crust.

Estimates of terrestrial heat flow in offshore eastern Canada

1985 ◽  
Vol 22 (10) ◽  
pp. 1503-1517 ◽  
Author(s):  
Marshall Reiter ◽  
Alan M. Jessop
Keyword(s):  
Heat Flow ◽  
Heat Generation ◽  
Newfoundland And Labrador ◽  
High Heat ◽  
Magmatic Activity ◽  
Shelf Edge ◽  
Eastern Canada ◽  
Heat Flows ◽  
Bottom Hole ◽  
Outer Half

From available bottom-hole temperatures and conductivities estimated from lithologic descriptions, heat-flow estimates are calculated for 72 sites on the Canadian Atlantic Shelf. The resulting data suggest a pattern of low heat flow (~055 mW/m2) within the Paleozoic basins in proximity to land areas and generally intermediate heat flow (~60–80 mW/m2) along the outer half of the continental shelf. Higher heat flows (~90 mW/m2) are estimated along the shelf edge in some areas, e.g., the southwestern Scotian Shelf and the eastern Newfoundland and Labrador shelves. Radioactive heat generation in sediments that thicken seawards probably does not account for the observed increase in heat flow. The possibility that higher heat flows in some areas may arise because of fluid movement from depth is suggested. Various other causes for the high heat flows, e.g., tectonic or magmatic activity, are considered less likely.

scholarly journals Assessment of the interval heat flow and thermal resistance at the Faltu-1 well, Borno basin, NE Nigeria

2021 ◽  
Vol 27 (2) ◽  
pp. 153-169
Author(s):  
S. Ali ◽  
K. Mosto-Onuoha
Keyword(s):  
Heat Flow ◽  
Oil And Gas ◽  
Thermal Resistivity ◽  
Reservoir Rocks ◽  
Heat Flows ◽  
Vertical Heat ◽  
Fluid Convection ◽  
Flow Heat ◽  
Magmatic Intrusions ◽  
Migration Pathways

The heat flowing through horizons in the Faltu-1 well, Borno Basin, NE Nigeria was calculated from their thermal conductivities and geothermal gradients with the aim of determining whether or not it is uniform, and if not, the depths where it is diverted, and the possible heat diversion process. The interval heat flow was assessed to be non-uniform. While fluid convection is adjudged to be the major heat diversion mechanism within the Chad Formation with minor heat refraction, the reversed is adjudged to be the situation for the underlying Kerri Kerri Formaton within which increasing sand content with depth is also predicted, with the lower interval predicted to be the Gombe Formation. Patterns of disruptions to the vertical heat flow within the Fika Formation were inferred to suggest rhythmic bedding of shale and sand beds that could serve as both source and reservoir rocks. Magmatic intrusions that impacted the maturation of organic matter into oil and gas also provided necessary entrapment structures and possible migration pathways. The Gongila and Bima Formations each has single disruption of the heat flows that are attributed to refraction. In the case of the Gongila Formation, the disruption is between the early-deposited more sandy and laterdeposited more shaley lithologies in the marine transgression of the area, while in the case of the Bima, it is between the more shaley Upper and more sandy Middle Bima Formations. Analysis of the Bullard plots also revealed disruptions to the vertical heat flow that are attributed either to convecting fluids or to heat refraction and diffraction. Two such disrupting heat advections were identified within the Chad Formation with the first being attributed to convection, while the other is attributed to a combination of both. Two similar disruptions for the Kerri Kerri Formation were attributed largely to lithological variations with minor contributions from convection of fluids. While unable to discern the rhythmic bedding, the five disruptions of the Bullard plot for the Fika Formation and one each for the Gongila and Bima Formations were interpreted to indicate similar features inferred from interval heat flow plots. Keywords: Interval heat flow, heat convection, heat diffraction, thermal resistivity, shaliness

The flow of heat through the floor of the Atlantic Ocean

1954 ◽  
Vol 222 (1150) ◽  
pp. 408-429 ◽  
Keyword(s):  
Heat Flow ◽  
Atlantic Ocean ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
High Heat ◽  
Unexpected Result ◽  
Heat Flows ◽  
The North ◽  
The Mean ◽  
The Individual

The measurement of the temperature gradient and thermal conductivity in the sediments beneath the floor of the North Atlantic Ocean is described. Measurements were made at five stations. The mean heat flow and conductivity were found to be 0·98 × 10 -6 cal/cm 2 s and 25 × 10 -4 cal/cm °Cs. The heat flows at the individual stations range from 0·58 to 1·42 × 10 -6 cal/cm 2 s. The high heat flow is an unexpected result, and it is difficult to find a source for so much heat.

Shallow Water Heat Flow Measurements in Bras D'or Lake, Nova Scotia

1971 ◽  
Vol 8 (1) ◽  
pp. 96-101 ◽  
Author(s):  
Douglas S. Rankin ◽  
Roy D. Hyndman
Keyword(s):  
Heat Flux ◽  
Nova Scotia ◽  
Heat Flow ◽  
Surface Temperature ◽  
Shallow Water ◽  
Thermal Gradient ◽  
Light Weight ◽  
Flow Measurements ◽  
Made In ◽  
Conductivity Contrast

A light-weight oceanic thermal gradient probe was used for heat flow studies in Bras d'Or Lake, Nova Scotia. The measurements were made in St. Andrew's Channel, an elongated trough 270 m deep and 540 m wide. The heat flux of 1.50 μcal/cm2 s (63 mW/m2) is corrected for sedimentation, conductivity contrast, topography, and surface temperature differences.

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