The relationship between heat flow and seismicity in global tectonically active zones

AbstractThis study aims to analyze the complex relationship between heat flow and seismicity in tectonically active zones worldwide. The problem was quantitatively analyzed by using a geographic detector method, which is well suited for analyzing nonlinear relationships in geography. Moreover, β-value that describes the frequency-magnitude distribution is used to represent the seismicity. The results showed that heat flow (HF) = 84 mW/m2 is a critical point for the relevant mechanisms of heat flow with seismicity in these zones. When HF < 84 mW/m2, the heat flow correlates negatively with the β-value, with a correlation degree of 0.394. Within this interval, buoyant is a primary control on the stress state and earthquake size distribution. Large earthquakes occur more frequently in subduction zones with younger slabs that are more buoyant. Due to zones with a high ratio of large earthquake corresponds to low β-values, high heat flow values correspond to low β-values. When HF > 84 mW/m2, the heat flow correlates positively with the β-value, with a correlation degree of 0.463. Within this interval, the increased heat flow decreases the viscosity of the rock plate and then reduces the stress. Lower stress would correspond to a smaller earthquake and then a higher β-value. Therefore, high heat flow values correspond to high β-values. This research would be conducive to understand the geologic activity and be helpful to determine the accuracy and timeliness of seismic hazard assessment.

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Thermal regime and hydrodynamics in Tunisia and Algeria

Geophysics ◽

10.1190/1.1443121 ◽

1991 ◽

Vol 56 (7) ◽

pp. 1093-1102 ◽

Cited By ~ 2

Author(s):

Hamed Ben Dhia

Keyword(s):

Heat Flow ◽

Transition Zone ◽

Thermal Regime ◽

High Heat ◽

Hydrodynamic Regime ◽

High Heat Flow ◽

Normal Heat ◽

Tectonically Active ◽

Potential Recharge ◽

Hydrodynamic Perturbation

The thermal regime of Algeria and Tunisia and its relation to hydrodynamics is studied by means of available geological and geothermal, and petroleum data. Heat flow densities in the area range from [Formula: see text] to [Formula: see text]. Several Paleozoic to Tertiary aquifers have been identified, together with potential recharge and discharge areas. The area is a transition zone between the African and European plates. The more tectonically active northern Alpine domain does not exhibit an obvious geothermal trend, and high heat flow anomalies that occur there may be related to structure rather than hydrodynamics. The more stable southern Saharan tectonic domain, with background heat flow of approximately [Formula: see text], exhibits anomalous zones correlated to the hydrodynamic regime with low values in recharge areas (Algerian Tinrhert and High Plateaux) and values in discharge areas (Tunisian Jeffara and Algerian Tademait). The hydrodynamic perturbation to the normal heat flow is estimated to be as great as [Formula: see text] in recharge and discharge zones.

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High heat flow under Deccan Traps causes uplift of Western India

Nature India ◽

10.1038/nindia.2009.87 ◽

2009 ◽

Keyword(s):

Heat Flow ◽

High Heat ◽

Deccan Traps ◽

Western India ◽

High Heat Flow

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High heat flow at the SW passive margin of the Gulf of California

Terra Nova ◽

10.1111/ter.12569 ◽

2021 ◽

Author(s):

Rosa Maria Prol‐Ledesma ◽

Juan Luis Carrillo De La Cruz ◽

Marco‐Antonio Torres‐Vera ◽

Alejandro Estradas‐Romero

Keyword(s):

Heat Flow ◽

Gulf Of California ◽

High Heat ◽

Passive Margin ◽

High Heat Flow

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A heat-flow reconnaissance of southeastern Alaska

Canadian Journal of Earth Sciences ◽

10.1139/e85-040 ◽

1985 ◽

Vol 22 (3) ◽

pp. 416-421 ◽

Cited By ~ 8

Author(s):

J. H. Sass ◽

L. A. Lawver ◽

R. J. Munroe

Keyword(s):

Heat Flow ◽

Plate Boundary ◽

Thermal Spring ◽

High Heat ◽

Transform Fault ◽

High Heat Flow ◽

Queen Charlotte Islands ◽

Late Tertiary ◽

The Mean ◽

Strain Heating

Heat flow was measured at nine sites in crystalline and sedimentary rocks of southeastern Alaska. Seven of the sites, located between 115 and 155 km landward of the Queen Charlotte – Fairweather transform fault, have an average heat flow of 59 ± 6 mW m−2. This value is significantly higher than the mean of 42 mW m−2 in the coastal provinces between Cape Mendocino and the Queen Charlotte Islands, to the south, and is lower than the mean of 72 ± 2 mW m−2 for 81 values within 100 km of the San Andreas transform fault, even farther south. This intermediate value suggests the absence of significant heat sinks associated with Cenozoic subduction and of heat sources related to either late Cenozoic tectono-magmatic events or significant shear-strain heating. At Warm Springs Bay, 75 km from the plate boundary, an anomalously high heat flow of 150 mW m−2 can most plausibly be ascribed to the thermal spring activity from which its name is derived. At Quartz Hill, 240 km landward of the plate boundary, a value of 115 mW m−2 might indicate a transition to a province of high heat flow resulting from late Tertiary and Quaternary extension and volcanism.

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High heat flow in the trans-Hudson Orogen, Central Canadian Shield

Geophysical Research Letters ◽

10.1029/96gl02895 ◽

1996 ◽

Vol 23 (21) ◽

pp. 3027-3030 ◽

Cited By ~ 29

Author(s):

L. Guillou-Frottier ◽

C. Jaupart ◽

J. C. Mareschal ◽

C. Gariépy ◽

G. Bienfait ◽

...

Keyword(s):

Heat Flow ◽

High Heat ◽

Canadian Shield ◽

High Heat Flow

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Gold in Irish Coal: Palaeo-Concentration from Metalliferous Groundwaters

Minerals ◽

10.3390/min10070635 ◽

2020 ◽

Vol 10 (7) ◽

pp. 635

Author(s):

Liam A. Bullock ◽

John Parnell ◽

Joseph G.T. Armstrong ◽

Magali Perez ◽

Sam Spinks

Keyword(s):

Heat Flow ◽

Low Temperature ◽

Precious Metals ◽

High Heat ◽

Selenium Content ◽

Foreland Basins ◽

High Heat Flow ◽

South Wales ◽

First Time ◽

Very High

Gold grains, up to 40 μm in size and containing variable percentages of admixed platinum, have been identified in coals from the Leinster Coalfield, Castlecomer, SE Ireland, for the first time. Gold mineralisation occurs in sideritic nodules in coals and in association with pyrite and anomalous selenium content. Mineralisation here may have reflected very high heat flow in foreland basins north of the emerging Variscan orogenic front, responsible for gold occurrence in the South Wales Coalfield. At Castlecomer, gold (–platinum) is attributed to precipitation with replacive pyrite and selenium from groundwaters at redox interfaces, such as siderite nodules. Pyrite in the cores of the nodules indicates fluid ingress. The underlying Caledonian basement bedrock is mineralised by gold, and thus likely provided a source for gold. The combination of the gold occurrences in coal in Castlecomer and in South Wales, proximal to the Variscan orogenic front, suggests that these coals along the front could comprise an exploration target for low-temperature concentrations of precious metals.

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Possible interrelation between the lead time of precursory seismic electric signals (SES) and geodynamics in Aegean Sea

Natural Hazards and Earth System Science ◽

10.5194/nhess-11-1599-2011 ◽

2011 ◽

Vol 11 (6) ◽

pp. 1599-1603 ◽

Cited By ~ 1

Author(s):

E. Dologlou

Keyword(s):

Heat Flow ◽

Flow Rate ◽

Lead Time ◽

Aegean Sea ◽

High Heat ◽

Heat Flow Rate ◽

Seismic Signals ◽

High Heat Flow ◽

Area North ◽

Electric Signals

Abstract. The seismicity of the last 15 years in the Aegean Sea revealed that earthquakes (Mw > 5) with epicentres falling within the Sporades basin and the confined area north of Samos island were preceded by electric seismic signals (SES) with a remarkably long lead time. A possible explanation of this behaviour by means of specific tectonics and geodynamics which characterise these two regions, such as a significant small crustal thickness and a high heat flow rate, has been attempted. New data seem to strengthen the above hypothesis.

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