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.

Evolution of Subduction Cusps From the Perspective of Trench Migration and Slab Morphology

The geometries of trenches vary worldwide due to continuous plate boundary reorganization. When two trenches intersect to generate a corner, a subduction cusp is formed. Although subduction cusps are frequently observed throughout historical plate movement reconstructions, few studies have been conducted to explore the controlling factors of trench migration and slab morphology along subduction cusps. Here, we use a 3-D dynamic subduction model to explore the influence of the overriding plate strength, initial slab-pull force, and initial cusp angle on the evolution of subduction cusps. Our numerical model results suggest the following: 1) subduction cusps have a tendency to become smooth and disappear during the subduction process; 2) the slab dip angle is smallest in the diagonal direction of the subduction cusp, and a larger cuspate corner angle leads to a larger slab dip angle; 3) the asymmetric distribution of the overriding plate strength and initial slab-pull force determine the asymmetric evolutionary pathway of subduction cusps. Our results provide new insights for reconstructing the evolution of subduction cusps from seismological and geological observations.

Geophysical Studies in the Southwest Pacific : Primarily Studies of Crustal Structure between New Zealand and Antarctica

<p>Geophysical data - primarily magnetic field measurements, bathymetry, and seismicity data - are presented for the area between New Zealand and Antarctica from approximately 145[degrees]W to 155[degrees]E. The data are used to determine the structure of the Pacific-Antarctic boundary, the oceanic part of the Pacific plate and the area of intersection of the Indian, Pacific and Antarctic plates. In the southwest Pacific basin the magnetic anomalies are very clear and an extensive pattern of anomaly lineations with some offsets is mapped. The magnetic anomalies show that the uniform Pacific basin area formed between about 83 and 63 mybp. The Pacific-Antarctic boundary is shown to differ either side of about 175[degrees]W. To the east it is a relatively uniform aseismic spreading ridge, offset by some transform faults. West of 175[degrees]W, to 161[degrees]E, the boundary consists of a seismically active zone of disturbed bathymetry and magnetic anomalies striking about N.70[degrees]W. The zone, the Pacific-Antarctic fracture zone, probably consists of several fractures striking about N45[degrees]W. The area between the Pacific-Antarctic boundary and the southwest Pacific basin represents the interval 10 to -55 mybp, and only in the east are anomaly lineations clear. The Indian-Antarctic Pacific triple junction is near 61.5[degrees]S, 161[degrees]E and is a stable ridge-fault-fault junction; the Indian-Antarctic boundary being the ridge. Plate tectonics is applied to the area and the structure is shown to fit, and be explained by a different rotation pole for each of the major intervals indicated by the structure, i.e. 0-10 mybp, 10-63 mybp and 63-80 mybp. The poles, with rotation rates deduced from the magnetic anomalies, are used to reconstruct the position of New Zealand relative to Antarctica at 80 mybp. The two continents probably started to separate at close to 83 mybp. The times of the major changes of structure and plate movement in the area are shown to coincide with major plate movement changes in the southwest Pacific area and in the rest of the world. A new method for determining poles of rotation, based only on epicentre locations is presented, The method is applied to independently determine the Indian-Pacific, Pacific-Antarctic and Indian-Antarctic poles. The poles should form a consistent. set and they do. The method yields effectively instantaneous poles, is quantitative, and is applicable to most plate boundaries. Earthquake magnitude-frequency relationship b values for the plate boundaries in the area are determined. Comparisons with results from elsewhere indicate an association of high b with high temperature and conversely. Several factors which have previously been suggested as determining b value are shown to not be determinants. A revised and extended magnetic reversal time scale based on model studies of the southwest Pacific basin anomalies is presented. Other model studies indicate that a magnetized layer thickness of at least 2 km is probable. Variations of anomaly amplitudes are studied. A detailed study of the application of numerical correlation techniques to magnetic anomalies is presented. It is concluded that horizontal scale variations and discontinuities in profiles can be critical. Methods for over-coming some of the problems, and for determining quantitative error estimates, are. given. The methods, and conclusions, are applicable to any correlation problem.</p>

Geophysical Studies in the Southwest Pacific : Primarily Studies of Crustal Structure between New Zealand and Antarctica

<p>Geophysical data - primarily magnetic field measurements, bathymetry, and seismicity data - are presented for the area between New Zealand and Antarctica from approximately 145[degrees]W to 155[degrees]E. The data are used to determine the structure of the Pacific-Antarctic boundary, the oceanic part of the Pacific plate and the area of intersection of the Indian, Pacific and Antarctic plates. In the southwest Pacific basin the magnetic anomalies are very clear and an extensive pattern of anomaly lineations with some offsets is mapped. The magnetic anomalies show that the uniform Pacific basin area formed between about 83 and 63 mybp. The Pacific-Antarctic boundary is shown to differ either side of about 175[degrees]W. To the east it is a relatively uniform aseismic spreading ridge, offset by some transform faults. West of 175[degrees]W, to 161[degrees]E, the boundary consists of a seismically active zone of disturbed bathymetry and magnetic anomalies striking about N.70[degrees]W. The zone, the Pacific-Antarctic fracture zone, probably consists of several fractures striking about N45[degrees]W. The area between the Pacific-Antarctic boundary and the southwest Pacific basin represents the interval 10 to -55 mybp, and only in the east are anomaly lineations clear. The Indian-Antarctic Pacific triple junction is near 61.5[degrees]S, 161[degrees]E and is a stable ridge-fault-fault junction; the Indian-Antarctic boundary being the ridge. Plate tectonics is applied to the area and the structure is shown to fit, and be explained by a different rotation pole for each of the major intervals indicated by the structure, i.e. 0-10 mybp, 10-63 mybp and 63-80 mybp. The poles, with rotation rates deduced from the magnetic anomalies, are used to reconstruct the position of New Zealand relative to Antarctica at 80 mybp. The two continents probably started to separate at close to 83 mybp. The times of the major changes of structure and plate movement in the area are shown to coincide with major plate movement changes in the southwest Pacific area and in the rest of the world. A new method for determining poles of rotation, based only on epicentre locations is presented, The method is applied to independently determine the Indian-Pacific, Pacific-Antarctic and Indian-Antarctic poles. The poles should form a consistent. set and they do. The method yields effectively instantaneous poles, is quantitative, and is applicable to most plate boundaries. Earthquake magnitude-frequency relationship b values for the plate boundaries in the area are determined. Comparisons with results from elsewhere indicate an association of high b with high temperature and conversely. Several factors which have previously been suggested as determining b value are shown to not be determinants. A revised and extended magnetic reversal time scale based on model studies of the southwest Pacific basin anomalies is presented. Other model studies indicate that a magnetized layer thickness of at least 2 km is probable. Variations of anomaly amplitudes are studied. A detailed study of the application of numerical correlation techniques to magnetic anomalies is presented. It is concluded that horizontal scale variations and discontinuities in profiles can be critical. Methods for over-coming some of the problems, and for determining quantitative error estimates, are. given. The methods, and conclusions, are applicable to any correlation problem.</p>

A New Multi-Scale Sliding Window LSTM Framework (MSSW-LSTM): A Case Study for GNSS Time-Series Prediction

GNSS time-series prediction plays an important role in the monitoring of crustal plate movement, and dam or bridge deformation, and the maintenance of global or regional coordinate frames. Deep learning is a state-of-the-art approach for extracting high-level abstract features from big data without any prior knowledge. Moreover, long short-term memory (LSTM) networks are a form of recurrent neural networks that have significant potential for processing time series. In this study, a novel prediction framework was proposed by combining a multi-scale sliding window (MSSW) with LSTM. Specifically, MSSW was applied for data preprocessing to effectively extract the feature relationship at different scales and simultaneously mine the deep characteristics of the dataset. Then, multiple LSTM neural networks were used to predict and obtain the final result by weighting. To verify the performance of MSSW-LSTM, 1000 daily solutions of the XJSS station in the Up component were selected for prediction experiments. Compared with the traditional LSTM method, our results of three groups of controlled experiments showed that the RMSE value was reduced by 2.1%, 23.7%, and 20.1%, and MAE was decreased by 1.6%, 21.1%, and 22.2%, respectively. Our results showed that the MSSW-LSTM algorithm can achieve higher prediction accuracy and smaller error, and can be applied to GNSS time-series prediction.

Determination of Motion Parameters of Selected Major Tectonic Plates Based on GNSS Station Positions and Velocities in the ITRF2014

Current knowledge about tectonic plate movement is widely applied in numerous scientific fields; however, questions still remain to be answered. In this study, the focus is on the determination and analysis of the parameters that describe tectonic plate movement, i.e., the position (F and L) of the rotation pole and angular rotation speed (w). The study was based on observational material, namely the positions and velocities of the GNSS stations in the International Terrestrial Reference Frame 2014 (ITRF2014), and based on these data, the motion parameters of five major tectonic plates were determined. All calculations were performed using software based on a least squares adjustment procedure that was developed by the author. The following results were obtained: for the African plate, Φ = 49.15 ± 0.10°, Λ = −80.82 ± 0.30°, and ω = 0.267 ± 0.001°/Ma; for the Australian plate, Φ = 32.94 ± 0.05°, Λ = 37.70 ± 0.12°, and ω = 0.624 ± 0.001°/Ma; for the South American plate, Φ = –19.03 ± 0.20°, Λ = −119.78 ± 0.39°, and ω = 0.117 ± 0.001°/Ma; for the Pacific plate, Φ = −62.45 ± 0.07°, Λ = 111.01 ± 0.14°, and ω = 0.667 ± 0.001°/Ma; and for the Antarctic plate, Φ = 61.54 ± 0.30°, Λ = −123.01 ± 0.49°, and ω = 0.241 ± 0.003°/Ma. Then, the results were compared with the geological plate motion model NNR-MORVEL56 and the geodetic model ITRF2014 PMM, with good agreement. In the study, a new approach is proposed for determining plate motion parameters, namely the sequential method. This method allows one to optimize the data by determining the minimum number of stations required for a stable solution and by identifying the stations that negatively affect the quality of the solution and increase the formal errors of the determined parameters. It was found that the stability of the solutions of the F, L, and w parameters varied depending on the parameters and the individual tectonic plates.

The Improvement in the Positioning on the Nubian and Somalia Plates by Updating Terrestrial Reference Frames

International Terrestrial Reference Frames (ITRF) is an accurate and standard frame for referencing positions at different times and in different locations around the world. The International Global Navigation Satellite System (GNSS) Service, (IGS) enable global positioning and timing at the highest possible accuracy through modernized datum’s aligned with the ITRF. In addition, ITRF site velocities for any location within Africa are between 24 and 31 mm/yr due to rigid motion of the African plate over the underlying mantle. The African plate can be divided into two Nubian and Somalia sub-plates. In the present work, the rotation rates about Euler poles and position improvement in Nubian and Somalia plates with updated ITRFs are investigated. Among the results in this study, when using a rigid plate movement and instantaneous ITRF coordinates to transform a fixed reference epoch, in case of Nubian plate, the residual in positioning and Root Mean Square Error (RMS) improved with the updating of the frame and the best results of residual and RMS appear in frame 2008 by values (0.149,0.011) m. respectively but in Somali plate, residual and RMS increased with the updating of the frame and the best results appear in frame2014 by values (i.,e., 0.096, 0.012) m, respectively.

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.

A Review of Dynamic Tree Behaviors: Measurement Methods on Tree Sway, Tree Tilt, and Root–Plate Movement

Urban forest ecosystems are being developed to provide various environmental services (e.g., the preservation of urban trees) to urban inhabitants. However, some trees are deteriorated asymptomatically without exhibiting an early sign of tree displacement, which results in a higher vulnerability under dynamic wind loads, especially during typhoon seasons, in the subtropical and tropical regions. As such, it is important to understand the tilt and sway behaviors of trees to cope up with the probability of tree failure and to improve the efficacy of tree management. Tree behaviors under wind loads have been broadly reviewed in the past literature, yet thorough discussions on the measurement methods for tree displacement and its analysis of broadleaf specimens are lacking. To understand the behavioral pattern of both broadleaf and conifer species, this paper presents a detailed review of sway behavior analysis from the perspectives of the aerial parts of the individual tree, including tree stem, canopy, and trunk, alongside a highlighted focus on the root–plate movement amid the soil-root system. The analytical approaches associated with the time-space domain and the time-frequency domain are being introduced. In addition to the review of dynamic tree behaviors, an integrated tree monitoring framework based on geographic information systems (GIS) to detect and visualize the extent of tree displacement using smart sensing technology (SST) is introduced. The monitoring system aims to establish an early warning indicator system for monitoring the displacement angles of trees over the territory of Hong Kong’s urban landscape. This pilot study highlights the importance of the monitoring system at an operational scale to be applicable in the urban areas showcasing the practical use of the Internet of Things (IoT) with an in-depth understanding of the wind-load effect toward the urban trees in the tropical and subtropical cities.

Crustal Deformation Across and beyond Central Europe and Its Impact on Land Boundaries

Land is a critical and limited natural resource. The Land Administration System (LAS) has been developed to resolve and adjudicate over any disputes that might arise concerning the rights and boundaries of land. Land registration and cadastre are types of land recording that need to be established. To secure the property rights, we must be sure of accuracy of the boundary points determining the size of the property. However, in addition to typical factors considered when determining the boundary point positions, such as accuracy of geodetic networks and measurement errors, the global and local crustal deformation, resulting, e.g., from the movement of tectonic plates, should be considered. In this work, the focus is on the movement of points inside the European plate due to tectonic movement, without taking into account local events caused by erosion, landslides, etc. The study area is Europe, and particular attention was paid to Poland, which is located in the centre of the European continent and does not have significant anomalous sub-areas, making it an authoritative research object. In this study, we analysed the velocity of point displacements and the boundary deformation, using GPS observations. For this reason, we used both global (IGS) and regional (ETRF) reference frames, to show differences in point velocities for the studied areas. Overall, for the needs of the real estate cadastre in Poland, information about parcel boundary points must be obtained with an accuracy better than 0.30 m. Within 25 years, the border mark may be shifted by 0.13 m due to tectonic plate movement, which is within the required accuracy. Pursuant to the current legal regulations, the measurements of the boundary points can be performed with any method, ensuring the required accuracy (0.30 m). The most commonly used are direct measurements (GNSS and tacheometry) and photogrammetric measurements. It is recommended that periodic verifications and update of the cadastre data in Poland be carried out at least once every 15 years. In the case of such relatively frequent verification and possible modernisation of data, the potential impact of tectonic plate movement on the relative boundary point displacement can be ignored, particularly in the short term. However, for a long time period it has an influence. We suggest “relatively frequent” cadastral boundary verification to be able to ignore such influence.