Constraints on lithospheric thermal structure for the Indian Ocean from depth and heat flow data

1993 ◽  
Vol 20 (11) ◽  
pp. 1095-1098 ◽  
Author(s):  
Tom Shoberg ◽  
Carol A. Stein ◽  
Seth Stein
Keyword(s):  
Indian Ocean ◽  
Heat Flow ◽  
Thermal Structure ◽  
Flow Data ◽  
The Indian Ocean ◽  
Lithospheric Thermal Structure

scholarly journals Adjoint inversion of the thermal structure of Southeastern Australia

2019 ◽  
Vol 219 (3) ◽  
pp. 1648-1659 ◽  
Author(s):  
B Mather ◽  
L Moresi ◽  
P Rayner
Keyword(s):  
Thermal Properties ◽  
Heat Flow ◽  
Heat Production ◽  
Thermal Structure ◽  
Surface Heat ◽  
Flow Data ◽  
Data Set ◽  
Surface Heat Flow ◽  
Southeastern Australia ◽  
Curie Depth

SUMMARY The variation of temperature in the crust is difficult to quantify due to the sparsity of surface heat flow observations and lack of measurements on the thermal properties of rocks at depth. We examine the degree to which the thermal structure of the crust can be constrained from the Curie depth and surface heat flow data in Southeastern Australia. We cast the inverse problem of heat conduction within a Bayesian framework and derive its adjoint so that we can efficiently find the optimal model that best reproduces the data and prior information on the thermal properties of the crust. Efficiency gains obtained from the adjoint method facilitate a detailed exploration of thermal structure in SE Australia, where we predict high temperatures within Precambrian rocks of 650 °C due to relatively high rates of heat production (0.9–1.4 μW m−3). In contrast, temperatures within dominantly Phanerozoic crust reach only 520 °C at the Moho due to the low rates of heat production in Cambrian mafic volcanics. A combination of the Curie depth and heat flow data is required to constrain the uncertainty of lower crustal temperatures to ±73 °C. We also show that parts of the crust are unconstrained if either data set is omitted from the inversion.

Towards a global lithospheric thermal model

2020 ◽  
Author(s):  
Sheona Masterton ◽  
Samuel Cheyney ◽  
Chris Green ◽  
Peter Webb
Keyword(s):  
Heat Flow ◽  
Curie Temperature ◽  
Thermal Structure ◽  
Magnetic Layer ◽  
Surface Heat ◽  
Local Context ◽  
Magnetic Data ◽  
Flow Data ◽  
Surface Heat Flow ◽  
Temperature Depth

<p>Temperature and heat flow are key parameters for understanding the potential for source rock maturation in sedimentary basins. Knowledge of the thermal structure of the lithosphere in both a regional and local context can provide important constraints for modelling basin evolution through time.</p><p>In recent years, global coverage of heat flow data constraints have enhanced scientific understanding of the thermal state of the lithosphere. However, sample bias and variability in sampling methods continues to be a major obstacle to heat flow-derived isotherm prediction, particularly in frontier areas where data are often sparse or poorly constrained. Consideration and integration of alternative approaches to predict temperature at depth may allow interpolation of surface heat flow in such data poor areas.   </p><p>We have attempted to integrate three independent approaches to modelling temperature with depth. The first approach is based on heat flow observations, in which a 1D steady-state model of the lithosphere is constructed from quality-assessed surface heat flow data, crustal thickness estimates and associated lithospheric thermal properties. The second approach is based on terrestrial (airborne, ground and shipborne) magnetic data, in which the maximum depth of magnetisation within the lithosphere is estimated using a de-fractal method and used as a proxy for Curie temperature depth. The third approach is based on satellite magnetic data and estimates the thickness of the magnetic layer within the lithosphere based on the varying amplitudes of satellite magnetic data, accounting for global variations in crustal magnetisation. Curie temperature depth results from each of these approaches have been integrated into a single global grid, then used to calculate temperature-depth variations through the crust.</p><p>We have evaluated our isotherm predictions by comparing them with temperature-depth control points and undertook qualitative and quantitative analyses of discrepancies that exist between different modelling approaches; this has provided insights into the origin of such discrepancies that can be integrated into our models to generate a better controlled global temperature-depth result.  </p><p>We present details of our methodology and the results of our integrated studies. We demonstrate areas where the independent results are in good agreement, providing vital information for high-level basin screening. We also highlight areas of disagreement and suggest possible causes for these discrepancies and potential resolutions.</p>

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

<p>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 “Thermal Data Collection in and around Japan”, 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.</p>

Thermal structure of the crust in the Black Sea: comparative analysis of magnetic and heat flow data

2014 ◽  
Vol 35 (4) ◽  
pp. 345-359 ◽  
Author(s):  
V. I. Starostenko ◽  
M. N. Dolmaz ◽  
R. I. Kutas ◽  
O. M. Rusakov ◽  
E. Oksum ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Heat Flow ◽  
Black Sea ◽  
Thermal Structure ◽  
The Black Sea ◽  
Flow Data

Heat flow and deep lithospheric thermal structure at Lac de Gras, Slave Province, Canada

2004 ◽  
Vol 31 (12) ◽  
pp. n/a-n/a ◽  
Author(s):  
J. C. Mareschal ◽  
A. Nyblade ◽  
H. K. C. Perry ◽  
C. Jaupart ◽  
G. Bienfait
Keyword(s):  
Heat Flow ◽  
Thermal Structure ◽  
Slave Province ◽  
Lithospheric Thermal Structure

A discussion concerning the floor of the northwest Indian Ocean - Heat flow in the northwest Indian Ocean and Red Sea

1966 ◽  
Vol 259 (1099) ◽  
pp. 271-278 ◽  
Keyword(s):  
Indian Ocean ◽  
Heat Flow ◽  
Red Sea ◽  
Deep Structure ◽  
Geothermal Gradient ◽  
Mean Value ◽  
Flow Measurements ◽  
Bottom Water Temperature ◽  
The Indian Ocean ◽  
Flow Through

Twenty-four measurements of the heat flow through the ocean floor were made in the Indian Ocean and three in the Red Sea. A critical analysis of the effects of fluctuations of bottom-water temperature on the geothermal gradient in the Red Sea shows that these fluctuations do not invalidate the measurements of heat flow. The mean value for the Gulf of Aden (this includes five previous measurements) is 3.89 + 0.49 /tcal cm -2 s -1 . This high value, combined with the shape of a profile across the Gulf, suggests a region of unusually high temperature at a depth of less than 10 km below the bottom. The seventeen heat flow measurements made by R.R.S. Discovery and R. V. Vema between the African coast and the Seychelles show little variation about a mean value of 1.17 /tcal cm -2 s -1 . The comparison of these observations and the deep structure, as determined by a series of seismic lines, shows a constant heat flow across the continental margin. The author is indebted to Mr R. Belderson of the National Institute of Oceanography for a brief description of the cores taken on the cruise.

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