Motion Of Lithospheric Plates Research Articles

1Al-Farabi Kazakh National University, Almaty, Kazakhstan

The article examines the distribution of current surface movements and changes due to the movement of lithospheric plates. Due to the proximity of the city of Almaty to the earthquake center, the occurrence of earthquakes, tectonic belts, geodynamic polygon zones, features of underground movement are described.

Theory of continental drift – causes of the motion. Outline of the theory

The theory of mantle convection currents as the cause of lithospheric plate movements has several major problems, including the absence of an adequate energy source. As shown in our previous contribution, an unbiased interpretation of geochemical data does not support the assumptions of a significant amount of radionuclides in the lower mantle or even in the core. It is our assertion that solar radiation is the primary energy source in the lithosphere. This energy is converted into mechanical energy via thermoelastic waves, even in depths with minimal temperature fluctuations. This has been confirmed by various methods of continuous stress measurement. The periodic and quasiperiodic thermoelastic reversible deformations, such as the circadian and annual cycles (including tidal periods), can also cause irreversible deformations due to the ratcheting mechanism. The 2D model showed that the strength limit is exceeded in 0.3 % of all diurnal cycles during the year. As a consequence, continents tend to extend while the oceanic lithosphere is pushed and overthrusted between continents. The middle-ocean ridges, similar to continental rifts, are filled by ascending magma which is one example of the ratcheting mechanism. The final plate movements are determined by the distribution of major continents and the overall westward drift of the lithosphere, which is slower for deep-rooted plates like the Indian one. Large asteroid impacts are important triggers (and possibly significant energy sources) of discrete events, like the formation of hotspots and large igneous provinces.

Impact of tidal friction on the motion of lithospheric plates and earthquake activity

AbstractThis paper draws attention to the contribution of tidal friction (TF) to plate tectonic processes. Our proposed model supports recent geodetic observations and geodynamic models highlighting exogenous local contributions to plate motions. The TF has a westward effect on lithospheric plates and the lithosphere as a whole. To determine the extent of this effect, we use the asthenospheric viscosity estimated using the Eötvös force. We also show that TF has a detectable impact on the latitudinal distribution of earthquake activity.

Theory of continental drift – causes of the motion. Historical review and observations

The theory of continental drift was published as early as 1912, but the mechanism and energy source of this motion has not yet been elucidated. In many cases, the generally accepted model of convection currents in the mantle contradicts observations such as the spreading of the ocean floor, the extension of rifts from triple points to all sides, the more or less unilateral movement of the lithosphere relative to the mantle, and others. In the first part of the double article, the evolution of views on this issue is shown, as well as measured data that document the important role of extraterrestrial energy sources for the movement of lithospheric plates in daily, annual and long-term climate cycles. In the second part of the two-part article, the entire theory of the mechanism of lithospheric plate motion will be outlined, based on the accumulation of incoming energy from the Sun in crustal rocks, the ratcheting mechanism, and the thermoelastic wave penetrating from the Earth's surface through the entire crust.

Lithospheric Plate Motion Model: Development and Current Status

Lithospheric Plate Motion Model: Development and Current Status

Zircon Dates Long‐Lived Plume Dynamics in Oceanic Islands

AbstractIn this contribution we report the first systematic study of zircon U‐Pb geochronology and δ18O‐εHf(t) isotope geochemistry from 10 islands of the hot‐spot related Galapagos Archipelago. The data extracted from the zircons allow them to be grouped into three types: (a) young zircons (0–∼4 Ma) with εHf(t) (∼5–13) and δ18O (∼4–7) isotopic mantle signature with crystallization ages dating the islands, (b) zircons with εHf(t) (∼5–13) and δ18O (∼5–7) isotopic mantle signature (∼4–164 Ma) which are interpreted to date the time of plume activity below the islands (∼164 Ma is the minimum time of impingement of the plume below the lithosphere), and (c) very old zircons (∼213–3,000 Ma) with mostly continental (but also juvenile) εHf(t) (∼−28–8) and δ18O (∼5–11) isotopic values documenting potential contamination from a number of sources. The first two types with similar isotopic mantle signature define what we call the Galápagos Plume Array (GPA). Given lithospheric plate motion, this result implies that GPA zircon predating the Galápagos lithosphere (i.e., >14–164 Ma) formed and were stored at sublithospheric depths for extended periods of time. In order to explain these observations, we performed 2D and 3D thermo‐mechanical numerical experiments of plume‐lithosphere interaction which show that dynamic plume activity gives rise to complex asthenospheric flow patterns and results in distinct long‐lasting mantle domains beneath a moving lithosphere. This demonstrates that it is physically plausible that old plume‐derived zircons survive at asthenospheric depths below ocean islands.

Geodynamic risks of developing rockburst-hazardous deposits in the Far Eastern region

Geodynamic activity of the Earth’s crust depends on the parameters of the movement of lithospheric plates and stress fields, both inherited in aseismic areas and modified in seismic active ones. Geomechanical processes occur in rock mass under the influence of various natural (endogenous and exogenous) and man-made (anthropogenic) factors. The degree of influence of these factors on the change in the energy saturation of blocks of various ranks will depend on various factors. In the geological environment of natural and man-made systems, there are dynamic phenomena of various energy levels from acoustic noise (microseismic) to rockburst and mining-induced earthquakes, that is, there is always a geodynamic risk in the geological environment of natural and man-made systems, especially in mining ones. The conditions of the geodynamic risks occurrence at specific deposits are considered on the example of rockburst hazardous deposits in the Far Eastern region of the Russian Federation. The influence of natural seismic activity on the realization of mining-induced seismicity is shown.

What Is the Impact of Tectonic Plate Movement on Country Size? A Long-Term Forecast

The Earth’s surface is under permanent alteration with the area of some nations growing or shrinking due to natural or man-made processes, for example sea level change. Here, based on the NUVEL 1A model, we forecast (in 10, 25, and 50 years) the changes in area for countries that are located on the border of the major tectonic plates. In the analysis we identify countries that are projected to gain or lose land due to the tectonic plate movement only. Over the next 50 years, the global balance of area gains (0.4 km2) and losses (12.7 km2) is negative. Thus, due to the movements of lithospheric plates, the land surface of the Earth will decrease by 12 km2 in 50 years. Overall, the changes are not that spectacular, as in the case of changes in sea/water levels, but in some smaller countries, projected losses exceed a few thousand square metres a year, e.g., in Nepal the losses exceed 10,000 m2 year−1. Methodologically, this paper finds itself between metric analysis and essay, trying to provoke useful academic discussion and incite educators’ interests to illustrate to students the tectonic movement and its force. Limitations of the used model have been discussed in the methodology section.

Closure of the Proterozoic Mozambique Ocean was instigated by a late Tonian plate reorganization event

Plate reorganization events involve fundamental changes in lithospheric plate-motions and can influence the lithosphere-mantle system as well as both ocean and atmospheric circulation through bathymetric and topographic changes. Here, we compile published data to interpret the geological record of the Neoproterozoic Arabian-Nubian Shield and integrate this with a full-plate tectonic reconstruction. Our model reveals a plate reorganization event in the late Tonian period about 720 million years ago that changed plate-movement directions in the Mozambique Ocean. After the reorganization, Neoproterozoic India moved towards both the African cratons and Australia-Mawson and instigated the future amalgamation of central Gondwana about 200 million years later. This plate kinematic change is coeval with the breakup of the core of Rodinia between Australia-Mawson and Laurentia and Kalahari and Congo. We suggest the plate reorganization event caused the long-term shift of continents to the southern hemisphere and created a pan-northern hemisphere ocean in the Ediacaran.

One Class of Problems of the Theory of Elasticity and Seismology and a Problem of Earthquake Prediction

Spatial quasi-static and dynamic problems of the theory of elasticity, simulating the behavior of lithospheric plates and blocks of Earth’s crust are solved for a layered package. According to the data of seismic stations, GPS, inclinometers, and other measuring instruments, slow (age-related) and transient motions of lithospheric plates are considered. It is shown that by carrying out regular measurements, based on the obtained solutions, it is possible to trace the entire process of preparation and occurrence of earthquakes.

Pattern of Global Crustal Stresses of the Earth

The results of tectonophysical inversion of the global tectonic stress field are considered from the position of explaining the active forces that cause the lithospheric plate movements. The analysis of regularities of the stress state of the main structural elements of Earth’s lithosphere—ocean spreading, transformations, active continental margins, and intracontinental orogeny—is performed. It is shown that the stresses in most of the ocean lithosphere, including subduction zones, correspond to active traction forces from the submerged and weighted part of the lithosphere. A low level of deviatoric stresses in subduction zones and the presence of dynamo pair with sharply different mode of stress state were found. Horizontal compression is observed in the crust of the continental slope, and horizontal tension is observed in the ocean lithosphere, so the boundaries of lithospheric plates should not be considered as a source of increased horizontal compressive stress in the crust of continents. The formation of a horizontal compression regime in the crust of intracontinental orogens, as well as in the crust of active continental margins orogens, is associated with residual stresses of rocks that have been exhumed from the depths of the crust. A generalizing scheme for the formation of the global crustal stress field of the Earth is proposed, which corresponds to modern data on the movements of lithospheric plates and the deep structure of the upper mantle.

Hot Times in Tectonophysics: Mantle Plume Dynamics and Magmatic Perturbances

Earth’s dynamic lithospheric (plate) motions often are not obvious when considered in relation to the temporal stability of the crust. Seismic radiology experiments confirm that the extreme pressures and temperatures in the mantle, and to a lesser extent the asthenosphere, result in a heterogeneously viscous rheology. Occasionally, magmatic fluid makes its way through the lithospheric plate to the surface, appearing typically as a volcano, fissure eruption, or lava flow. When occurring away from the edges of plate boundaries, these long-lasting suppliers of lava, present over millions of years, are called mantle plumes, or ‘hotspots.’ Conventional definitions of mantle plumes note that they are stationary with respect to each other and the motion of the plates, passively tracing historical plate motion in volcanic formations such as the Hawaiian-Emperor island arc – the Plate Model. In this model, mantle plumes primarily occur as a consequence of lithospheric extension.Recent empirical studies, however, have demonstrated that hotspots are not as geographically consistent as previously thought. They may move in relation to each other, as well as contribute actively toward lithospheric plate motions – the Plume Model. There is a lively, ongoing debate between the Plate and Plume hypotheses, essentially seeking to determine if mantle flow is merely a passive reaction to lithospheric plate motion (Plate Model), or whether plume activity in part drives this motion (Plume Model). More likely, it is a combination of passive and active mantle plume components that better describe the comprehensive behavior of these important and distinctive landscape forming features.

О возможных океанических явлениях при горизонтальных движениях литосферных плит

О возможных океанических явлениях при горизонтальных движениях литосферных плит

Subduction tectonics vs. Plume tectonics—Discussion on driving forces for plate motion

Plate tectonics describes the horizontal motions of lithospheric plates, the Earth’s outer shell, and interactions among them across the Earth’s surface. Since the establishment of the theory of plate tectonics about half a century ago, considerable debates have remained regarding the driving forces for plate motion. The early “Bottom up” view, i.e., the convecting mantle-driven mechanism, states that mantle plumes originating from the core-mantle boundary act at the base of plates, accelerating continental breakup and driving plate motion. Toward the present, however, the “Top down” idea is more widely accepted, according to which the negative buoyancy of oceanic plates is the dominant driving force for plate motion, and the subducting slabs control surface tectonics and mantle convection. In this regard, plate tectonics is also known as subduction tectonics. “Top down” tectonics has received wide supports from numerous geological and geophysical observations. On the other hand, recent studies indicate that the acceleration/deceleration of individual plates over the million-year timescale may reflect the effects of mantle plumes. It is also suggested that surface uplift and subsidence within stable cratonic areas are correlated with plume-related magmatic activities over the hundred-million-year timescale. On the global scale, the cyclical supercontinent assembly and breakup seem to be coupled with superplume activities during the past two billion years. These correlations over various spatial and temporal scales indicate the close relationship and intensive interactions between plate tectonics and plume tectonics throughout the history of the Earth and the considerable influence of plumes on plate motion. Indeed, we can acquire a comprehensive understanding of the driving forces for plate motion and operation mechanism of the Earth’s dynamic system only through joint analyses and integrated studies on plate tectonics and plume tectonics.

MOUNTAINS AS STABILIZERS FOR EARTH FROM THE QURANIC AND MODERN SCIENCE PERSPECTIVES

The main thought and foundation in Islamic civilization is based from the teaching and learning of Quran. There are many secrets and mysteries in Quran and the only way to uncover it is by reading, understanding and researching its content. Among the miracles stated in the Quran, there are 49 times mentioned about mountain in different form of words and sentence structure hence its meaning. Therefore, this study will discuss and uncover the scientific evidence related to the mountain that is mentioned in the Quran. The method of this study is qualitative approach which most of the data are collected from library and literary materials that related to the word ‘mountain’. In Quran, it has mentioned mountain as the pillar of earth which strengthen its ground and enable other being to inhabit it. Meanwhile, from the perspectives of scientific evidences claimed that when two continents collide, stronger plates will slip beneath the other plate and creating a platform that restrict the movement of the continent to avoid shaking. Then, the upper one folds and will form the mountain plate. This depicts that without mountains, the lithospheric plate movements will be eroded drastically. All this information has been mentioned in Quran as the word ‘rawasiya’ and will be discussed along in this paper accordingly Keywords: Mountain, Quran, stabilizer.

Comparative analysis of modern deformation and the newest motions of the Earth surface in the territory of Ukraine

Currently, the data of the Global Navigation Satellite Systems (GNSS) are widely used in the field of navigation, geodesy, cartography and regional geodynamic studies, in particular, in monitoring the movement of lithospheric plates, etc. Further development and creation of local GNSS networks, as well as the long-term replenishment of databases regarding the determination of the coordinates of individual stations and the speeds of their movement allows obtaining reliable more detailed information on the current deformation of the Earth's surface. The article discusses the current deformation of the Earth’s surface based on the analysis of the Global Navigation Satellite Systems data from the GAO NAS of Ukraine in comparison with the heights of the UGK2012 quasi-geoid and the latest lineament zones and faults, as well as with the late Pliocene-Quaternary vertical movements of the Earth’s crust. According to the results of the analysis of high-precision coordinates of displacement vectors of permanent GNSS stations in the territory of Ukraine, deformation parameters of the Earth’s surface were obtained, areas of prevailing compression values — tension and left-right-side rotation of the Earth’s surface were identified, the boundaries between which can be drawn along the latest lineament zones and faults. The areas of the predominant stretching of the Earth’s surface correspond to the zones of the newest tectonic uplifts (Volyn-Podolsk and Periazov hills) and maximum amplitudes of the Pliocene-Quaternary movements and positive geoid anomalies, and the areas of prevailing compression are zones of tectonic descents (Polissian and Peridnieper lowland), minimal amplitudes of Pliocene-Quarternary movements and minor heights of the geoid. Four large modern geoblocks have been identified: North-West and North-East, which rotate clockwise, and South-West and South-East rotating counterclockwise. At a qualitative level, the mechanism of interconnection of modern and newest movements of the Earth’s crust, namely, the presence of the latest tectonic zones of uplifting and lowering with corresponding tensions and movements of its surface, on which modern tensions (and corresponding movements) are imposed that are associated with the tectonic movement of the Eurasian Plate in northeastern direction and the irregular rotation of the Earth.

Mantle flow and deep electrical anisotropy in a main gateway: MT study in Tierra del Fuego

Asthenospheric mantle flow drives lithospheric plate motion and constitutes a relevant feature of Earth gateways. It most likely influences the spatial pattern of seismic velocity and deep electrical anisotropies. The Drake Passage is a main gateway in the global pattern of mantle flow. The separation of the South American and Antarctic plates since the Oligocene produced this oceanic and mantle gateway connecting the Pacific and Atlantic oceans. Here we analyze the deep crustal and upper mantle electrical anisotropy of its northern margin using long period magnetotelluric data from Tierra del Fuego (Argentina). The influence of the surrounding oceans was taken into account to constrain the mantle electrical conductivity features. 3D electrical models were calculated to fit 18 sites responses in this area. The phase tensor pattern for the longest periods reveals the existence of a well-defined NW-SE electrical conductivity anisotropy in the upper mantle. This anisotropy would result from the mantle flow related to the 30 to 6 Ma West Scotia spreading, constricted by the subducted slab orientation of the Pacific plate, rather than the later eastward mantle flow across the Drake Passage. Deep electrical anisotropy proves to be a key tool for a better understanding of mantle flow.

ОСОБЕННОСТИ МОРФОЛОГИИ И КИНЕМАТИКИ ВОСТОЧНОГО СЕГМЕНТА ЮГО-ЗАПАДНО-ИНДИЙСКОГО ХРЕБТА МЕЖДУ ТРАНСФОРМНЫМ РАЗЛОМОМ МЕЛВИЛЛ И ТРОЙНЫМ СОЧЛЕНЕНИЕМ РОДРИГЕС

The eastern segment of the Southwest Indian Ridge is a unique wedge-shaped structure. The absence of transform faults in this region is explained by young age, anomalously low crustal power, and ultra slow spreading, at which spatial stresses are compensated by local fracture. The plan shows the presence of two fracture systems: one was probably caused by tensile stresses of global order associated with the movement of lithospheric plates, and the other is an evidence of local stretching processes. The clear longitudinal segmentation of the Southwest Indian Ridge was most likely caused by local planned transformanions that occurred during the wedge opening. Compilation of facts obtained during the voyage of the R/V «Akademik Nikolai Strakhov» and literature data allows us to conclude that the opening of the basin most likely follows the scenario of a passive compensatory gap initiated by the global geodynamic restructuring of the structural plan in the Indian Ocean.

Source Models of the 2012 Haida Gwaii (Canada) and 2015 Illapel (Chile) Earthquakes and Numerical Simulations of Related Tsunamis

Seismological observations provide essential input parameters for numerical tsunami simulations. Here, we present source mechanism parameters, finite-fault source rupture models and numerical tsunami simulation results for the destructive October 28, 2012 Haida Gwaii-Canada (Mw 7.7) and September 16, 2015 Illapel-Chile (Mw 8.3) earthquakes and resulting tsunamis. These two earthquakes were controlled by active tectonic features along the subduction zones that had developed in response to the convergent movements of lithospheric plates. The faulting geometry (strike, dip, and rake angles), focal depth, fault dimensions, average and maximum slip values on the fault planes and seismic moments of the earthquakes are estimated by analyzing teleseismic long-period P- and SH-waves and broadband P-waveforms and using waveform inversion and hybrid back-projection methods. The obtained slip models of the earthquakes reveal heterogeneous slip distributions on fault planes with long source durations (~ 80 s and 150 s) and low stress drop values (10–15 bars). Numerical simulations of tsunami wave propagation are further performed using the uniform and non-uniform slip models and nonlinear long-wave equations in spherical coordinates. The shape and arrival times of leading tsunami waves are adequately constrained particularly with the heterogeneous slip distribution models. The general characteristics of synthetic tsunami waveforms (e.g., amplitude, shape, arrival time) calculated using the non-uniform slip model, are more consistent with the observed tsunami records than those of a uniform slip model. It is further seen that simulation results using preliminary and fast slip models for both earthquakes give only approximate early tsunami estimates; tsunami wave heights and arrival times to the coasts are mostly not well simulated. The results indicate that tsunami simulations based on finite-fault source slip models likely contribute to the determination of tsunamigenic coastal regions by revealing locations, arrival times, amplitudes, and directions of tsunami waves within a close approximation to observed records off-shore and far from the source region. They provide sufficient information to facilitate tsunami warning and mitigation challenges after the destructive earthquakes. We further suggest that joint inversions of GPS, tsunami, teleseismic and strong ground motion records and higher resolution bathymetry data are needed in order to obtain better correlations between observed and synthetic tsunami data, especially for the later arriving waves.

On a mechanical approach to the prediction of earthquakes during horizontal motion of lithospheric plates

The block element method is used to study a static boundary value problem for semi-infinite lithospheric plates interacting with a deformable basement along Conrad boundary. It is assumed that the lithospheric plates have straight line boundaries parallel to each other and are considered in two positions. In the first case, the distance between the ends of the plates does not vanish, whereas in the second case the distance is absent, although the plates do not interact. It is assumed that horizontal action on the plates, which are known to move extremely slowly, is so strong that vertical components of contact stresses can be neglected. Only shift stresses remain in the contact zone. The paper addresses the comparison of numerical simulation and block element approach to investigate this problem. In the first case, appearance of a concentration of contact stresses in the zone of contact of lithospheric plates is found, while in the second case the stress concentration turns out to be singular and leads to destruction of the base or edges of the lithospheric plates. In the second case, it is possible to determine the influence of various parameters of the problem on the magnitude of the coefficients for singularities in the contact stress concentrations. The numerical method does not have this capability. The obtained result allows one to predict the starting earthquakes based on monitoring of horizontal motions of the lithospheric plates.