GPS Observations Research Articles

Postseismic deformation due to the 2021 MW 7.4 Maduo (China) earthquake and implications for regional rheology and seismic hazards around the Bayan Har block

GPS and InSAR observations of the first ∼1.5 years of postseismic deformation caused by the 2021 MW 7.4 Maduo earthquake provide a valuable opportunity to investigate fault interactions and regional rheological structure, as well as the future seismic potential around the Bayan Har block, northeastern Tibetan Plateau. We develop an integrated model to simulate the afterslip and viscoelastic relaxation contributions to the observed postseismic displacements, and found that afterslip driven by the coseismic stress is concentrated downdip of rupture, and dominates the postseismic deformation in the early stage (∼0.4 year after the event). Because afterslip decays quickly over time, viscoelastic relaxation should become the main postseismic mechanism as time goes on. The two mechanisms produce similar displacements during 0.4–1.5 years after the earthquake, but at 1.5 years after the earthquake the velocity caused by viscoelastic relaxation is larger than that caused by afterslip. Viscoelastic models assuming either a Burgers body or power-law rheology produce very similar predictions, with the Burgers body model having a slightly lower overall misfit. The rheological structure constrained by the postseismic observations supports the 35-km thick elastic upper crust overlying a Burgers body viscoelastic lower curst with a Maxwell viscosity of 3 × 1019 Pa s (5 - 50 × 1018 Pa s at 95% confidence), assuming the Kelvin viscosity is equal to 10% of that value. This is different from the regional rheology inferred by the postseismic investigations on the 2001 MW 7.8 Kokoxili and the 2008 MW 7.8 Wenchuan events, and the preferred thickness of the elastic crust is also different from that inferred from magnetotelluric profiles deployed in previous studies. We thus infer that the rheological structure within the Bayan Har block is possibly heterogeneous from west to east. Finally, the normal stress changes triggered by the coseismic rupture and postseismic process are estimated to be negative, but the shear stress changes to be positive on the western Kunlun fault, the eastern Dari fault and Bayan-Har Mountain fault. However, the current observations and studies are quite insufficient on those fault segments, therefore, we need to focus on their faulting behavior and seismic risk in the future.

Inland Summer Speedup at Zachariæ Isstrøm, Northeast Greenland, Driven by Subglacial Hydrology

AbstractThe Northeast Greenland Ice Stream (NEGIS) has experienced substantial dynamic thinning in recent years. Here, we examine the evolving behavior of NEGIS, with focus on summer speedup at Zachariae Isstrøm, one of the NEGIS outlet glaciers, which has exhibited rapid retreat and acceleration, indicative of its vulnerability to changing climate conditions. Through a combination of Sentinel‐1 data, in‐situ GPS observations, and numerical ice flow modeling from 2007, we investigate the mechanisms driving short‐term changes. Our analysis reveals a summer speedup in ice flow both near the terminus and inland, with satellite data detecting changes up to 60 km inland, while GPS data capture changes up to 190 km inland along the glacier center line. We attribute this summer speedup to variations in subglacial hydrology, where surface meltwater runoff influences basal friction over the melt season. Incorporating subglacial hydrology into numerical models makes it possible to replicate observed ice velocity patterns.

First Detections of Ionospheric Plasma Density Irregularities from GOES Geostationary GPS Observations during Geomagnetic Storms

In this study, we present the first results of detecting ionospheric irregularities using non-typical GPS observations recorded onboard the Geostationary Operational Environmental Satellites (GOES) mission operating at ~35,800 km altitude. Sitting above the GPS constellation, GOES can track GPS signals only from GPS transmitters on the opposite side of the Earth in a rather unique geometry. Although GPS receivers onboard GOES are primarily designed for navigation and were not configured for ionospheric soundings, these GPS measurements along links that traverse the Earth’s ionosphere can be used to retrieve information about ionospheric electron density. Using the radio occultation (RO) technique applied to GPS measurements from the GOES–16, we analyzed variations in the ionospheric total electron content (TEC) on the links between the GPS transmitter and geostationary GOES GPS receiver. For case-studies of major geomagnetic storms that occurred in September 2017 and August 2018, we detected and analyzed the signatures of storm-induced ionospheric irregularities in novel and promising geostationary GOES GPS observations. We demonstrated that the presence of ionospheric irregularities near the GOES GPS RO sounding field of view during geomagnetic disturbances was confirmed by ground-based GNSS observations. The use of RO observations from geostationary orbit provides new opportunities for monitoring ionospheric irregularities and ionospheric density.

Analysis of Comparability of PCV in Surveying-Grade GNSS Antenna – Topcon HIPER-VR Case Study

ABSTRACT It is well known that the phase center of a Global Navigation Satellite System (GNSS) antenna is not a stable point. For any given GNSS antenna, the phase center will change with the direction of the incoming signal from a satellite, as well as the frequency. Ignoring these phase center variations (PCVs) in GNSS data processing can lead to notable errors, especially in vertical position component determination. To avoid the problem, antenna PCV together with the phase center offset (PCO) information are recommended to be used in GNSS observation processing. We currently distinguish between individual and type-mean phase center correction (PCC) models. These models describe the variations in the phase center of the antenna as a function of the elevation angle and azimuth. In general, the primary difference between individual and type-mean models lies in their specificity. Individual models are highly precise but are valid only for a particular antenna model, while the type-mean models are more general and can be applied to a broad range of antennas of the same type, but may suffer from a lower level of precision. This paper aims to analyze the comparability of PCV in surveying-grade GNSS antennas. For the analyses, we propose to use an originally designed bench with precisely defined relative positions of the seven antenna mounting points. Preliminary studies have been performed using GPS observations on L1 and L2 frequencies recorded by seven Topcon HIPER-VR antennas. The results proved that the comparability of PCV for this antenna is high. The position error did not exceed 3 mm. It could be assumed that the type-mean PCC model could describe PCV all antennas of this type with good accuracy.

An Integrated Study of Age and Formation of the Aru Trough, Eastern Banda Arc, Indonesia: Implications for Seismic Hazards

AbstractThe Banda Arc in eastern Indonesia has a complex tectonic history involving oceanic and continental subduction, arc‐continent collision and slab rollback. Among these the subduction rollback that began at 16 Ma shaped the regional tectonic configuration, causing notable upper plate extension evidenced by the Banda Sea and Weber Deep. However, the effects of subduction rollback on the lower plate remain less understood. The Aru Trough, part of subducting Australian continental margin, shows strong deformation and high seismicity, making it ideal for studying these effects. Utilizing multibeam bathymetry, seismic reflection profiles, GPS observations, seismicity and focal mechanisms, we investigate the crustal deformation, driving mechanisms and seismic risks in the Aru Trough under the background of Banda slab rollback. The Aru Trough shaped like an inverted triangle narrows from 160 to 40 km southward. It has a fast 53.8 mm/yr extensional rate at present, when combined with its maximum width suggesting a 3 Ma age. High‐angle faults (>60°) are present at its margins and interior. The trough has a high density of seismicity up to 5.9 events per 25 km2, with dominant normal and strike‐slip events, consistent with observed deformational patterns. The low seismic b‐value of 0.82 ± 0.01 suggests a high‐stress state with potential for strong earthquakes (Mw ≥ 6.5). Our findings indicate that lower plate deformation is profoundly influenced by subduction rollback, oblique arc‐continent collision and regional strike‐slip faulting. Understanding deformation in the Aru Trough is crucial for grasping the broader tectonic evolution of the Banda Arc and assessing seismic risks.

The Spatiotemporal properties of afterslip following the 2016 Kaikoura earthquake in New Zealand from GPS observations: Its complementary and inherited patterns with coseismic slip

The Spatiotemporal properties of afterslip following the 2016 Kaikoura earthquake in New Zealand from GPS observations: Its complementary and inherited patterns with coseismic slip

Dynamic Characterization of Equatorial Plasma Bubble Based on Triangle Network‐Joint Slope Approach

AbstractThis paper introduces a Triangle Network‐Joint Slope (TN‐JS) approach to characterize the spatial and temporal dynamics of Equatorial Plasma Bubbles (EPBs) during geomagnetic storms. To collaboratively determine the EPB drift directions from multiple stations, a Delaunay triangle network is constructed, utilizing the distribution of Ionospheric Piercing Points (IPPs). The Time Difference of Arrival (TDOA) is extracted through cross‐correlating the Rate of Total Electron Content (ROT). The EPB drift direction can be approximately calculated by considering TDOA and IPP distances within each individual triangle of the network. This calculation is then refined through a joint statistical analysis. Using a reference station as the origin, the remaining stations within the network are projected along the estimated EPB drift direction. A spatial‐temporal color map illustrating regional ionospheric anomaly ROT observations is constructed. The EPB drift velocity among multiple stations can be collectively estimated by fitting the slope of this map, facilitating outlier exclusion. Accounting for satellite dynamic effects and the diverse orbit characteristics of GPS and BDS, corresponding IPP scan velocity compensation is performed and analyzed for EPB dynamic estimation. Using the geomagnetic storm event that occurred on September 8 as a case study, the spatial‐temporal kinetic properties of EPBs is characterized by analyzing Global Navigation Satellite System (GNSS) observations from 17 Hong Kong monitoring stations with the proposed TN‐JS approach. The results indicate during this magnetic event, that EPBs exhibit a westward drift trend with velocities ranging from a few tens to hundreds of meters per second in GPS and BDS observations.

Correction to: Ionospheric scintillation characteristics over Indian region from latitudinally-aligned geodetic GPS observations

AbstractThe article “Ionospheric scintillation characteristics over Indian region from latitudinally-aligned geodetic GPS observations” was originally published Online First without open access. After publication in volume 16, issue 3, page 2675–2691, the author decided to opt for Open Choice and to make the article an open access publication.

Synergistic use of SAR satellites with deep learning model interpolation for investigating of active landslides in Cuenca, Ecuador

Among the most intense geological disasters, landslides frequently occur throughout the world. These phenomena have been studied using space geodetic techniques, including Global Navigation Satellite Systems (GNSS) and Multi-Temporal Interferometric Synthetic Aperture Radars (MT-InSAR). Nevertheless, complete mapping and analysis of landslides’ surface deformation in most areas can be complicated due to a large diversity in kinematics, such as periods of quiescence and acceleration in the toe and crown. One of these landslides is the Cuenca landslides in Ecuador, where the geological investigation revealed that the toe of the landslides was located in urban areas, with more noticeable deformation effects. In contrast, its crown was located mainly in a rural and green land area. In this study, we show the potential of a synergistic use of COSMO-SkyMed (CSK) and Sentinel-1A (S1A) synthetic aperture radar (SAR) data for comprehensively monitoring the Cuenca landslides. To this aim, we have used Long-Short Term Memory (LSTM) and Convolutional Neural Networks (CNN) as two different Deep Learning Algorithms (DLAs) to integrate results in the temporal and spatial domain, respectively. A cross-comparison of the results was made with the nine GPS-derived deformations and the visual effects (i.e. crack width and pattern) on the field. This validation against GPS observation reveals that the RMSEs of the final MT-InSAR-derived velocity after applying the synergic double band SAR dataset decrease at more than 73% of nine GPS stations. Highlights Synergic MT-InSAR approach for studying landslide deformation in diverse kinematic areas. Utilized DLAs (LSTM and CNNs) for effective temporal and spatial interpolation of InSAR results. Findings emphasize the potential of multi-sensor SAR and DLAs for landslide monitoring regarding improving the RMSE at nine stations with an average of 73%.

Fault system dynamics of the Kashmir, NW Himalaya, India using continuous GPS observations and geomorphic evidences

We collected data from the continuous Global Positioning System (cGPS) sites across the Kashmir Valley, situated at latitude 34◦N, spanning from 2008 to 2021. Inter-site velocities define a region of approximately 15,000 km2 with broadly distributed strain accumulation at −7.22×10−8 nano strain/year (compression component) and the maximum shear strain γmax of 1.9051×10−7 nano strain/year. The estimated site velocity in the ITRF14 ranges between 30.5±1–42.85±3 mm/yr. It was observed that the average deformation rate of the GPS sites in the Kashmir region ranges between 2.86±1–15.47±3 mm/yr relative to the India fixed reference frame, suggesting a predominant N-S directed compressional tectonic regime. The focal mechanism solutions of the earthquakes in and around the Kashmir Valley suggest dominant thrust faulting followed by normal faulting. Analysis of the vertical component of the GPS time series shows that the northwest segment of the valley subsides at the rate of −1.71± 0.70 mm/yr, while the southeast segment uplifts at the rate of 5.4 ± 0.5 mm/yr. In addition to vertical component, we observed differential movement of the sites relative to IISC site on the northwest and southeast segments. The rate of baseline change of the GPS sites indicates 7.30 ± 0.75 mm/yr extension in SE-NW direction and −5.32 ± 0.75 mm/yr NE-SW compression across and along the Kashmir Valley. Geodetic observations reveal a transition that aligns with the Magam lineament/fault previously identified by Ganju and Khar (1984) using gravity and magnetic data. The observation was supported by the field investigations and remote sensing techniques, confirming the existence of Magam Fault. During the field investigations, various geomorphic expressions of fault were observed, including fault ruptures, fault scarps, offset ridges, deflected drainages/rivers, linear alignment of springs, linear drainage lines, triangular facets and offset Recent sedimentary deposits (Karewas) were observed. The field evidence suggests exposure of normal faults at Kondabal, Nasrullapora, Biru and Radbugh. These exposed extensional structures, trends in NE-SW direction and dip in NW direction with varying offset and dip amount. GPS observations supplemented by geomorphic evidences infer the presence of normal fault ̴ 80 Km extending from northeast to southwest.

ACCURACY ANALYSIS OF UAV COORDINATES USING EGNOS AND SDCM AUGMENTATION SYSTEMS

SBAS systems are applied in precise positioning of UAV. The paper presents the results of studies on the improvement of UAV positioning with the use of the EGNOS+SDCM solutions. In particular, the article focuses on the application of the model of totaling the SBAS positioning accuracy to improve the accuracy of determining the coordinates of UAVs during the realisation of a test flight. The developed algorithm takes into account the position errors determined from the EGNOS and SDCM solutions. as well as the linear coefficients that are used in the linear combination model. The research was based on data from GPS observations and SBAS corrections from the AsteRx-m2 UAS receiver installed on a Tailsitter platform. The tests were conducted in September 2020 in northern Poland. The application of the proposed algorithm that sums up the positioning accuracy of EGNOS and SDCM allowed for the improvement of the accuracy of determining the position of the UAV by 82-87% in comparison to the application of either only EGNOS or SDCM. Apart from that, another important result of the application of the proposed algorithm was the reduction of outlier positioning errors that reduced the accuracy of the positioning of UAV when a single SBAS solution (EGNOS or SDCM) was used. The study also presents the effectiveness of the proposed algorithm in terms of calculating the accuracy of EGNOS+SDCM positioning for the weighted average model. The developed algorithm may be used in research conducted on other SBAS supporting systems.

Satellite orbit determination and time synchronization using GPS single-frequency observables in low and high solar activities

We assess the orbit accuracy and time synchronization error using the L1 and C1 observables during the different solar activities. In general, GPS single-frequency (SF) observable can be used for commercial applications in satellite industry. The accuracy of satellite orbit determination using the SF observations is dominated by solar activities. The solar activities are indexed by the F10.7 value. The different solar activities lead to the ionosphere perturbation, triggering off the occurrence probability of ionospheric irregularities. The ionospheric irregularity affects the amplitude and phase of GPS signal. The affected amplitude and phase are indexed by the S4 value. We determine the GRACE satellite orbit using the SF GPS observations and compare the resulting orbit to that derived by dual-frequency observations for the effectiveness. The SF phase data are very sensitive to the variation in electron density and indirectly affects both the orbit accuracy and the time synchronization error. This is most likely caused by the phase ambiguity disturbed by the ionosphere. However, the C1 is relatively free from such a disturbance due to the strong signal-to-noise ratio (SNR) and the phase shift keying technique. The C1 performs the consistent solution over the low and high solar activities. However, this is not the case for the L1. The L1-derived orbit solution during the high solar activities is worse than that during the low solar activities. On the other hand, the time synchronization errors derived by the L1 and C1 are also different. The L1-derived time synchronization error has a relatively large perturbation as compared to the C1-derived one, which shows a consistent solution for a long-term period. This work suggests that the C1 observable is able to produce a consistent the orbit solution and time synchronization for the commercial applications of the satellite industry.Graphical

Ionosphere-Weighted Network Real-Time Kinematic Server-Side Approach Combined with Single-Differenced Observations of GPS, GAL, and BDS

Ionosphere-Weighted Network Real-Time Kinematic Server-Side Approach Combined with Single-Differenced Observations of GPS, GAL, and BDS

Non‐Linear Vertical Land Motion of Coastal Chile and the Antarctic Peninsula Inferred From Combining Satellite Altimetry, Tide Gauge and GPS Data

AbstractWe developed an enhanced Kalman‐based approach to quantify abrupt changes and significant non‐linearity in vertical land motion (VLM) along the coast of Chile and the Antarctic Peninsula using a combination of multi‐mission satellite altimetry (ALT), tide gauge (TG), and GPS data starting from the early 1990s. The data reveal the spatial variability of co‐seismic and post‐seismic subsidence at TGs along the Chilean subduction zone in response to the Mw8.8 Maule 2010, Mw8.1 Iquique 2014, and Mw8.3 Illapel 2015 earthquakes that are not retrievable from the interpolation of sparse GPS observations across space and time. In the Antarctic Peninsula, where continuous GPS data do not commence until ∼1998, the approach provides new insight into the ∼2002 change in VLM at the TGs of +5.3 ± 2.2 mm/yr (Palmer) and +3.5 ± 2.8 mm/yr (Vernadsky) due to the onset of ice‐mass loss following the Larsen‐B Ice Shelf breakup. We used these data to constrain viscoelastic Earth model parameters for the northern Antarctic Peninsula, obtaining a preferred lithosphere thickness of 115 km and upper mantle viscosity of 0.9 × 1018 Pa s. Our estimates of regionally‐correlated ALT systematic errors are small, typically between ∼±0.5–2.5 mm/yr over single‐mission time scales. These are consistent with competing orbit differences and the relative errors apparent in ALT crossovers. This study demonstrates that, with careful tuning, the ALT‐TG technique can provide improved temporal and spatial sampling of VLM, yielding new constraints on geodynamic models and assisting sea‐level change studies in otherwise data sparse regions and periods.

Possible seismo-ionospheric anomalies of Mw 6.0 and 6.4 south Iran twin earthquakes on 14 November 2021 from GPS and ionosonde observations

Possible seismo-ionospheric anomalies of Mw 6.0 and 6.4 south Iran twin earthquakes on 14 November 2021 from GPS and ionosonde observations

Singular spectrum analysis for the time-variable seasonal signals from GPS in Yunnan Province

Studying the seasonal deformation in GPS time series is important to interpreting geophysical contributors and identifying unmodeled and mismodeled seasonal signals. Traditional seasonal signal extraction used the least squares method, which models seasonal deformation as a constant seasonal amplitude and phase. However, the seasonal variations are not constant from year to year, and the seasonal amplitude and phase are time-variable. In order to obtain the time-variable seasonal signal in the GPS station coordinate time series, singular spectrum analysis (SSA) is conducted in this study. We firstly applied the SSA on simulated seasonal signals with different frequencies 1.00 cycle per year (cpy), 1.04 cpy and with time-variable amplitude are superimposed. It was found that SSA can successfully obtain the seasonal variations with different frequencies and with time-variable amplitude superimposed. Then, SSA is carried out on the GPS observations in Yunnan Province. The results show that the time-variable amplitude seasonal signals are ubiquitous in Yunnan Province, and the time-variable amplitude change in 2019 in the region is extracted, which is further explained by the soil moisture mass loading and atmospheric pressure loading. After removing the two loading effects, the SSA obtained modulated seasonal signals which contain the obvious seasonal variations at frequency of 1.046 cpy, it is close with the GPS draconitic year, 1.040 cpy. Hence, the time-variable amplitude changes in 2019 and the seasonal GPS draconitic year in the region could be discriminated successfully by SSA in Yunnan Province.

Improved GRACE-FO kinematic orbit determination with epoch-difference KBR during the GPS flex power period

The flex power technology in satellite navigation systems enhances anti-jamming capabilities but can impact the quality of GPS observations and the accuracy of low Earth orbit determination, such as GRACE Follow-On (GRACE-FO) mission. This study investigates the influence of GPS flex power on Hatch-Melbourne-Wübbena (HMW) linear combinations and GRACE-FO kinematic orbits from January 1 to September 30, 2020. Epoch-differenced K-Band Ranging (KBR) data is introduced in orbit determination during the flex power period to improve both absolute and inter-satellite relative accuracy. The analysis indicates that the influence of early flex power (before February 13, 2020) on HMW combinations and orbits is minimal, whereas the effect of later flex power (after February 14, 2020) is significant: (1) HMW combinations exhibit notable systematic discontinuities even with elevation angles greater than 50 degrees, causing the fixing rate of wide-lane ambiguities to drop from 96 % to 80 %. (2) Kinematic absolute orbits show significant deteriorations of approximately 9 mm and 4 mm in the three-dimensional direction for float and integer ambiguity resolution (FAR and IAR), while relative accuracy of FAR and IAR orbits decreases by 50 % and 46 %, respectively. However, using epoch-differenced KBR (DKBR) data, the accuracy of absolute orbits could be increased by up to 15 % and the accuracy of relative orbits could be improved by at least 69 %, which showcases a positive effect. Thus, this can be considered as an alternative method to improve the accuracy of GRACE-FO orbit during the flex power period.

Sentinel-6 Michael Freilich precise orbit determination using PODRIX and TriG receiver measurements

The Sentinel-6 Michael Freilich altimetry mission flies two GNSS receivers: a primary multi-GNSS (GPS plus Galileo) PODRIX receiver and a GPS-only TriG receiver. Each of these receivers is independently capable of supporting the precise orbit determination (POD) requirement for < 1.5 cm radial rms error. In this study, we characterize the performance of single-receiver solutions and evaluate the benefits of a combined TriG and PODRIX orbit solution. The availability of both sets of receiver observations revealed a 10 mm in-track difference between orbit solutions derived independently from TriG and PODRIX tracking data. Based on satellite laser ranging (SLR) residuals, this bias has been isolated to an apparent inconsistency between the estimated TriG receiver clock and observation time-tags of approximately 1.3 μs\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mu \\hbox {s}$$\\end{document}, which is equivalent to a common range error of roughly 400 m in the TriG observations. After applying this calibration, the TriG and PODRIX displayed similar performance in terms of orbit overlap precision. PODRIX-Galileo observations showed lower code and phase tracking residual rms values compared to the GPS observations. Overall, processing the calibrated TriG and PODRIX observations separately results in highly accurate orbit solutions with radial orbit accuracies better than 1 cm rms as indicated by one-way SLR residual rms of 7.2 mm or better for each solution. Orbit solution accuracy is slightly improved by processing both TriG and PODRIX observations together, resulting in one-way SLR residual rms of 7.0 mm.

GPS-Based Precise Orbit Determination of LEO Satellites Using Space-Based Double-Differenced Observations

One of the important GPS applications in space is precise orbit determination (POD) of Low-Earth Orbit (LEO) satellites. Thousands of LEO satellites are currently in orbit. One of the challenges is how to efficiently and precisely determine the orbits to satisfy the relative and absolute accuracy needs of missions. Currently, GPS-based POD of LEO satellites can be performed using either un-differenced (UD) or ground-based double-differenced (DD) observations. The UD POD needs both precise GPS satellite orbits and clocks; the DD POD needs not only the precise orbits, but also global ground reference receivers. Therefore, the GPS-based LEO POD is based on either global ground stations or precise GNSS clocks, which are not convenient for near real-time or real-time data processing. The GPS orbits can be precisely predicted in certain time; the clocks are not. For some formation flying satellite missions (two or more LEO satellites), the absolute orbit accuracy requirements are not as stringent as the relative requirements. The problem is how to perform LEO POD without global station data and precise GPS clocks in near real-time or real-time to achieve the mission orbit accuracy requirement. Based on this motivation, we investigated the GPS-based LEO POD using space-based DD observations without using global ground station GPS data and precise GPS clock products. For this study, we processed the real GPS observations from two LEO satellites. The absolute and relative orbit accuracy is assessed using several tests, including analysis of the orbit fits, external orbit comparisons, Satellite Laser Ranging (SLR) and K-band Ranging (KBR) residuals.

Investigation into potential TEC changes due to 9 seismic tremors of 2021–2022

This research document delves into the analysis of alterations in Total Electron Content (TEC) as identified through GPS observations leading up to nine earthquakes that transpired between the late months of 2021 and 2022. The comprehensive study investigates the TEC variations and provides a detailed examination of heat maps centred around the earthquake epicentres. These heat maps, characterized by diverse latitudes and longitudes, play a pivotal role in validating the precise locations of the earthquake epicentres. Notably, the examination of these maps unveils discernible GPS TEC variations several days before the occurrence of each earthquake. In addition to the TEC analysis, the research sheds light on the fluctuations in solar magnetic parameters. The study elucidates instances where TEC peaks surpassed normal values, particularly during periods characterized by minimal solar radiation effects. This correlation between solar magnetic parameters and TEC fluctuations adds a nuanced layer to the understanding of the complex interplay of factors leading to seismic events. The cumulative findings derived from the investigation point towards a compelling conclusion: GPS TEC observations and the analysis of heat maps serve as indispensable indicators for identifying precursory signs that precede an impending earthquake. This multidimensional approach enhances our comprehension of the temporal and spatial aspects of seismic activity and underscores the potential significance of solar magnetic parameters in influencing such geophysical events.