scholarly journals Regional estimation of Curie-point depths and succeeding geothermal parameters from recently acquired high-resolution aeromagnetic data of the entire Bida Basin, north-central Nigeria

2017 ◽  
Vol 5 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Levi I. Nwankwo ◽  
Abayomi J. Sunday
Keyword(s):  
High Resolution ◽  
Heat Flow ◽  
Curie Point ◽  
Thermal Structure ◽  
Geothermal Gradient ◽  
North Central ◽  
Geodynamic Processes ◽  
Regional Estimation ◽  
Heat Flow Variations ◽  
Geothermal Parameters

<p><strong>Abstract.</strong> A regional estimation of Curie-point depths (CPDs) and succeeding geothermal gradients and subsurface crustal heat flow has been carried out from the spectral centroid analysis of the recently acquired high-resolution aeromagnetic (HRAM) data of the entire Bida Basin in north-central Nigeria. The HRAM data were divided into 28 overlapping blocks, and each block was analysed to obtain depths to the top, centroid, and bottom of the magnetic sources. The depth values were then used to assess the CPD, geothermal gradient, and subsurface crustal heat flow in the basin. The result shows that the CPD varies between 15.57 and 29.62<span class="thinspace"></span>km with an average of 21.65<span class="thinspace"></span>km, the geothermal gradient varies between 19.58 and 37.25<span class="thinspace"></span>°C<span class="thinspace"></span>km<sup>−1</sup> with an average of 27.25<span class="thinspace"></span>°C<span class="thinspace"></span>km<sup>−1</sup>, and the crustal heat flow varies between 48.41 and 93.12<span class="thinspace"></span>mW<span class="thinspace"></span>m<sup>−2</sup> with an average of 68.80<span class="thinspace"></span>mW<span class="thinspace"></span>m<sup>−2</sup>. Geodynamic processes are mainly controlled by the thermal structure of the Earth's crust; therefore this study is important for appraisal of the geo-processes, rheology, and understanding of the heat flow variations in the Bida Basin, north-central Nigeria.</p>

scholarly journals Evaluation of geothermal energy resources in parts of southeastern sedimentary basin, Nigeria

2021 ◽  
Vol 23 (1) ◽  
pp. 195-211
Author(s):  
I.M. Okiyi ◽  
S.I. Ibeneme ◽  
E.Y. Obiora ◽  
S.O. Onyekuru ◽  
A.I. Selemo ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Heat Flow ◽  
Curie Point ◽  
Geothermal Energy ◽  
Sedimentary Basin ◽  
Geothermal Gradient ◽  
Geothermal System ◽  
Magnetic Vector ◽  
Geothermal Gradients ◽  
Vector Inversion

Residual aeromagnetic data of parts of Southeastern Nigerian sedimentary basin were reduced to the equator and subjected to magnetic vector inversion and spectral analysis. Average depths of source ensembles from spectral analysis were used to compute depth to magnetic tops (Z), base of the magnetic layer (Curie Point t Depth (CPD)), and estimate geothermal gradient and heat flow required for the evaluation of the geothermal resources of the study area. Results from spectral analysis showed depths to the top of the magnetic source ranging between 0.45 km and 1.90 km; centroid depths of 4 km - 7.87 km and CPD of between 6.15 km and 14.19 km. The CPD were used to estimate geothermal gradients which ranged from 20.3°C/km to 50.0°C/km 2 2 and corresponding heat flow values of 34.9 mW/m to 105 mW/m , utilizing an average thermal conductivity -1 -1 of 2.15 Wm k . Ezzagu (Ogboji), Amanator-Isu, Azuinyaba, Nkalagu, Amagunze, Nta-Nselle, Nnam, Akorfornor environs are situated within regions of high geothermal gradients (>38°C/Km) with models delineated beneath these regions using 3D Magnetic Vector Inversion, having dominant NW-SE and NE-SW trends at shallow and greater depths of <1km to >7 km bsl. Based on VES and 2D imaging models the geothermal system in Alok can be classified as Hot Dry Rock (HDR) type, which may likely have emanated from fracture systems. There is prospect for the development of geothermal energy in the study area. Keywords: Airborne Magnetics, Magnetic Vector Inversion, Geothermal Gradient, Heat Flow, Curie Point Depth, Geothermal Energy.

scholarly journals Estimation of Geothermal Gradient and Heat Flow for Determination of Geothermal Energy Sources in Monguno Area of Northeastern Nigeria

2019 ◽  
pp. 1-8
Author(s):  
B. C. Udochukwu ◽  
M. Akiishi ◽  
A. A. Tyovenda
Keyword(s):  
Heat Flow ◽  
Curie Point ◽  
Geothermal Energy ◽  
Geothermal Gradient ◽  
High Heat ◽  
Curie Point Depth ◽  
The South ◽  
Geothermal Resources ◽  
North East ◽  
Curie Depth

The aeromagnetic data of Monguno area northeastern Nigeria have been used to estimate Curie point depth, geothermal gradients and heat flow using spectral analysis. These geothermal parameters were subsequently employed to identify areas of geothermal resources. First order polynomial fitting was applied in Regional-residual separation. The Curie point depth obtained in this area ranges from 10.318 to 24.476 km with an average of 13.387 km, the geothermal gradient of the area varies from 23.697 to 56.212°C /km, with an average of 46.195°C /km, while the heat flow ranges from 59.242 to 136.176 mWm-2, with an average value of about 112.364 mWm-2. It was also observed that the deepest Curie depth in the area is identified in the south, while the shallow depth is located in the northeast and spread toward the southwest. On the other hand, the highest geothermal gradient in the area is identified in the northern part of Moguno, while in the south,                    the lowest, geothermal gradient is located. The highest heat flow in the area is seen in the south-west and north-east, while the lowest heat flow is observed in the south. The high heat flow and geothermal gradient in the area show that geothermal energy could be found in Monguno region of the northeastern Nigeria.

Thermal data collection in and around Japan and its implications for lithospheric rheology and deformation

2020 ◽  
Author(s):  
Akiko Tanaka
Keyword(s):  
Heat Flow ◽  
Data Collection ◽  
Depth Distribution ◽  
Thermal State ◽  
Thermal Structure ◽  
Geothermal Gradient ◽  
Geological Processes ◽  
Thermal Data ◽  
Lithospheric Thermal Structure ◽  
Geochemical Constraints

&lt;p&gt;Heat flow data contribute to the imaging the lithospheric thermal structure, which greatly influences tectonic and geological processes and constrains the strength of the lithosphere, the modes of deformation, and the depth distribution of earthquakes. To provide more reliable estimation of the lithospheric thermal structure, some complementary approaches are possible. One of approaches is to update and incorporate the existing thermal data. A new version of database &amp;#8220;Thermal Data Collection in and around Japan&amp;#8221;, which contains continuously updated of heat flow and geothermal gradient data and adds thermal conductivity data in and around Japan, has been released in March 2019 [https://www.gsj.jp/data/G01M/GSJ_MAP_TDCJ_2019.zip]. This provides an opportunity to revisit the thermal state of the lithosphere along with other geophysical/geochemical constraints and on the lithospheric rheology and deformation, which is sensitive to temperature.&lt;/p&gt;

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