Evolution of stress fields during the supercontinent cycle
We investigate the evolution of stress fields during the supercontinent cycle using the 2D Cartesian geometry model of thermochemical convection with the non-Newtonian rheology in the presence of floating deformable continents. In the course of the simulation, the supercontinent cycle is implemented...
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| Format: | Article |
| Language: | English |
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KeAi Communications Co., Ltd.
2022-06-01
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| Series: | Geodesy and Geodynamics |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1674984722000180 |
| _version_ | 1817977468862070784 |
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| author | Alexander Bobrov Alexey Baranov Robert Tenzer |
| author_facet | Alexander Bobrov Alexey Baranov Robert Tenzer |
| author_sort | Alexander Bobrov |
| collection | DOAJ |
| description | We investigate the evolution of stress fields during the supercontinent cycle using the 2D Cartesian geometry model of thermochemical convection with the non-Newtonian rheology in the presence of floating deformable continents. In the course of the simulation, the supercontinent cycle is implemented several times. The number of continents considered in our model as a function of time oscillates around 3. The lifetime of a supercontinent depends on its dimension. Our results suggest that immediately before a supercontinent breakup, the over-lithostatic horizontal stresses in it (referring to the mean value by the computational area) are tensile and can reach −250 MPa. At the same time, a vast area beneath a supercontinent with an upward flow exhibits clearly the over-lithostatic compressive horizontal stresses of 50–100 МРа. The reason for the difference in stresses in the supercontinent and the underlying mantle is a sharp difference in their viscosity. In large parts of the mantle, the over-lithostatic horizontal stresses are in the range of ±25 MPa, while the horizontal stresses along subduction zones and continental margins are significantly larger. During the process of continent-to-continent collisions, the compressive stresses can approximately reach 130 MPa, while within the subcontinental mantle, the tensile over-lithostatic stresses are about −50 MPa. The dynamic topography reflects the main features of the supercontinent cycle and correlates with real ones. Before the breakup and immediately after the disintegration of the supercontinent, continents experience maximum uplift. During the supercontinent cycle, topographic heights of continents typically vary within the interval of about ±1.5 km, relatively to a mean value. Topographic maxima of orogenic formations to about 2–4 km are detected along continent-to-continent collisions as well as when adjacent subduction zones interact with continental margins. |
| first_indexed | 2024-04-13T22:16:51Z |
| format | Article |
| id | doaj.art-d1c52c048f0f420da797bbb53146bb9d |
| institution | Directory Open Access Journal |
| issn | 1674-9847 |
| language | English |
| last_indexed | 2024-04-13T22:16:51Z |
| publishDate | 2022-06-01 |
| publisher | KeAi Communications Co., Ltd. |
| record_format | Article |
| series | Geodesy and Geodynamics |
| spelling | doaj.art-d1c52c048f0f420da797bbb53146bb9d2022-12-22T02:27:30ZengKeAi Communications Co., Ltd.Geodesy and Geodynamics1674-98472022-06-01134363375Evolution of stress fields during the supercontinent cycleAlexander Bobrov0Alexey Baranov1Robert Tenzer2Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, RussiaSchmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia; Institute of Earthquake Prediction Theory and Mathematical Geophysics, Russian Academy of Sciences, Moscow, Russia; Corresponding author. Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia.Department of Land Surveying and Geo-Informatics, Hong Kong Polytechnic University, Hong Kong, ChinaWe investigate the evolution of stress fields during the supercontinent cycle using the 2D Cartesian geometry model of thermochemical convection with the non-Newtonian rheology in the presence of floating deformable continents. In the course of the simulation, the supercontinent cycle is implemented several times. The number of continents considered in our model as a function of time oscillates around 3. The lifetime of a supercontinent depends on its dimension. Our results suggest that immediately before a supercontinent breakup, the over-lithostatic horizontal stresses in it (referring to the mean value by the computational area) are tensile and can reach −250 MPa. At the same time, a vast area beneath a supercontinent with an upward flow exhibits clearly the over-lithostatic compressive horizontal stresses of 50–100 МРа. The reason for the difference in stresses in the supercontinent and the underlying mantle is a sharp difference in their viscosity. In large parts of the mantle, the over-lithostatic horizontal stresses are in the range of ±25 MPa, while the horizontal stresses along subduction zones and continental margins are significantly larger. During the process of continent-to-continent collisions, the compressive stresses can approximately reach 130 MPa, while within the subcontinental mantle, the tensile over-lithostatic stresses are about −50 MPa. The dynamic topography reflects the main features of the supercontinent cycle and correlates with real ones. Before the breakup and immediately after the disintegration of the supercontinent, continents experience maximum uplift. During the supercontinent cycle, topographic heights of continents typically vary within the interval of about ±1.5 km, relatively to a mean value. Topographic maxima of orogenic formations to about 2–4 km are detected along continent-to-continent collisions as well as when adjacent subduction zones interact with continental margins.http://www.sciencedirect.com/science/article/pii/S1674984722000180Supercontinent cycleFloating deformable continentsThermochemical convectionHorizontal stressesDynamic topography |
| spellingShingle | Alexander Bobrov Alexey Baranov Robert Tenzer Evolution of stress fields during the supercontinent cycle Geodesy and Geodynamics Supercontinent cycle Floating deformable continents Thermochemical convection Horizontal stresses Dynamic topography |
| title | Evolution of stress fields during the supercontinent cycle |
| title_full | Evolution of stress fields during the supercontinent cycle |
| title_fullStr | Evolution of stress fields during the supercontinent cycle |
| title_full_unstemmed | Evolution of stress fields during the supercontinent cycle |
| title_short | Evolution of stress fields during the supercontinent cycle |
| title_sort | evolution of stress fields during the supercontinent cycle |
| topic | Supercontinent cycle Floating deformable continents Thermochemical convection Horizontal stresses Dynamic topography |
| url | http://www.sciencedirect.com/science/article/pii/S1674984722000180 |
| work_keys_str_mv | AT alexanderbobrov evolutionofstressfieldsduringthesupercontinentcycle AT alexeybaranov evolutionofstressfieldsduringthesupercontinentcycle AT roberttenzer evolutionofstressfieldsduringthesupercontinentcycle |