Heat flow in the western abyssal plain of the Gulf of Mexico: Implications for thermal evolution of the old oceanic lithosphere

1996 ◽  
Vol 101 (B2) ◽  
pp. 2895-2913 ◽  
Author(s):  
S. Nagihara ◽  
J. G. Sclater ◽  
J. D. Phillips ◽  
E. W. Behrens ◽  
T. Lewis ◽  
...  
Keyword(s):  
Heat Flow ◽  
Gulf Of Mexico ◽  
Thermal Evolution ◽  
Oceanic Lithosphere ◽  
Abyssal Plain

scholarly journals Oceanic strike-slip faults represent active fluid conduits in the abyssal sub-seafloor

Geology ◽  
2021 ◽  
Author(s):  
Christian Hensen ◽  
Florian Scholz ◽  
Volker Liebetrau ◽  
Norbert Kaul ◽  
Marianne Nuzzo ◽  
...  
Keyword(s):  
Heat Flow ◽  
Plate Boundary ◽  
Oceanic Lithosphere ◽  
Strike Slip ◽  
Abyssal Plain ◽  
Transport Reaction ◽  
Sea Mud ◽  
The One ◽  
Restraining Bend ◽  
Flower Structures

We present pore-fluid geochemistry and heat-flow data along the SWIM1 fault in the Horseshoe Abyssal Plain (northeastern Atlantic Ocean). The SWIM1 fault is part of the transcurrent plate boundary between Africa and Eurasia and cuts through as much as 5-km-thick sediments overlying >140 Ma oceanic lithosphere. In a number of places, restraining segments (as long as 15 km) of the SWIM1 fault generate anticlines (positive flower structures) that protrude as ~100-m-high hills above the abyssal plain. Heat flow and gradients of dissolved constituents in pore water are enhanced at these seafloor highs. Transport-reaction modeling confirms that slow advection of deep-seated fluids, depleted in Mg and enriched in Sr and CH4, can explain the observations. The geochemical signature is similar to the one observed at deep-sea mud volcanoes located eastward on the SWIM1 fault. The upward-migrating fluids have interacted with carbonate rocks at maximum 5 km depth, which represent the oldest sedimentary unit on top of the basement. We argue that deep-rooted fluids can generally be mobilized and transported upward along flower structures that formed in restraining-bend segments of long strike-slip faults. Such tectonic settings represent largely unrecognized corridors for mass exchange between lithosphere and ocean.

Adiabatic Heat Flow in Mercury with a Fe-8.5wt%Si Core

2021 ◽  
Author(s):  
Meryem Berrada ◽  
Richard Secco ◽  
Wenjun Yong
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Internal Structure ◽  
High Pressures ◽  
Inner Core ◽  
Thermal Evolution ◽  
The Core ◽  
Thermally Driven ◽  
Wire Method ◽  
Core Conditions

<p>Recent theoretical studies have tried to constrain Mercury’s internal structure and composition using thermal evolution models. The presence of a thermally stratified layer of Fe-S at the top of an Fe-Si core has been suggested, which implies a sub-adiabatic heat flow on the core side of the CMB. In this work, the adiabatic heat flow at the top of the core was estimated using the electronic component of thermal conductivity (k<sub>el</sub>), a lower bound for thermal conductivity. Direct measurements of electrical resistivity (ρ) of Fe-8.5wt%Si at core conditions can be related to k<sub>el</sub> using the Wiedemann-Franz law. Measurements were carried out in a 3000 ton multi-anvil press using a 4-wire method. The integrity of the samples at high pressures and temperatures was confirmed with electron-microprobe analysis of quenched samples at various conditions. Unexpected behaviour at low temperatures between 6-8 GPa may indicate an undocumented phase transition. Measurements of ρ at melting seem to remain constant at 127 µΩ·cm from 10-24 GPa, on both the solid and liquid side of the melting boundary. The adiabatic heat flow at the core side of Mercury’s core-mantle boundary is estimated between 21.8-29.5 mWm<sup>-2</sup>, considerably higher than most models of an Fe-S or Fe-Si core yet similar to models of an Fe core. Comparing these results with thermal evolution models suggests that Mercury’s dynamo remained thermally driven up to 0.08-0.22 Gyr, at which point the core became sub-adiabatic and stimulated a change from dominant thermal convection to dominant chemical convection arising from the growth of an inner core. Simply considering the internal structure of Mercury, these results support the capture of Mercury into a 3:2 resonance orbit during the thermally driven era of the dynamo.</p>

Thermal evolution of the Sierra Nevada: Tectonic implications of new heat flow data

Tectonics ◽  
1991 ◽  
Vol 10 (2) ◽  
pp. 325-344 ◽  
Author(s):  
Richard W. Saltus ◽  
Arthur H. Lachenbruch
Keyword(s):  
Heat Flow ◽  
Sierra Nevada ◽  
Thermal Evolution ◽  
Flow Data ◽  
Tectonic Implications

Planetary heat flow measurements

2005 ◽  
Vol 363 (1837) ◽  
pp. 2777-2791 ◽  
Author(s):  
Axel Hagermann
Keyword(s):  
Heat Flow ◽  
Thermal Evolution ◽  
Tectonic Activity ◽  
Heat Sources ◽  
Flow Measurements ◽  
Planetary Body ◽  
Ocean Ridges ◽  
Heat Engines ◽  
Rosetta Mission ◽  
History Of

The year 2005 marks the 35th anniversary of the Apollo 13 mission, probably the most successful failure in the history of manned spaceflight. Naturally, Apollo 13's scientific payload is far less known than the spectacular accident and subsequent rescue of its crew. Among other instruments, it carried the first instrument designed to measure the flux of heat on a planetary body other than Earth. The year 2005 also should have marked the launch of the Japanese LUNAR-A mission, and ESA's Rosetta mission is slowly approaching comet Churyumov-Gerasimenko. Both missions carry penetrators to study the heat flow from their target bodies. What is so interesting about planetary heat flow? What can we learn from it and how do we measure it? Not only the Sun, but all planets in the Solar System are essentially heat engines. Various heat sources or heat reservoirs drive intrinsic and surface processes, causing ‘dead balls of rock, ice or gas’ to evolve dynamically over time, driving convection that powers tectonic processes and spawns magnetic fields. The heat flow constrains models of the thermal evolution of a planet and also its composition because it provides an upper limit for the bulk abundance of radioactive elements. On Earth, the global variation of heat flow also reflects the tectonic activity: heat flow increases towards the young ocean ridges, whereas it is rather low on the old continental shields. It is not surprising that surface heat flow measurements, or even estimates, where performed, contributed greatly to our understanding of what happens inside the planets. In this article, I will review the results and the methods used in past heat flow measurements and speculate on the targets and design of future experiments.

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