Ocean Tide Loading Research Articles

Tidally modulated seismic velocity changes observed using submarine dark fiber and the virtual-source method

Natural cyclical stress perturbations, including wet and solid earth tides, coupled with repeatable seismic monitoring approaches, provide a tool for understanding the elastic properties of rocks at depth. Ocean tides, in particular, perturb the overburden and pore pressure, affecting hydraulic and elastic rock properties. The recent emergence of distributed acoustic sensing (DAS) and seismology using existing dark telecom fiber offers an unprecedented opportunity to instrument the seas and oceans with seismic monitoring networks of large aperture, fine spatial resolution, and broadband sensitivity. We use a submarine dark-fiber array to methodologically assess whether the changes in seafloor seismic velocities are modulated by ocean tidal loading. Considering oceanic ambient noise (AN) in the frequency range between 1 and 5 Hz, we find it possible to retrieve reliable surface-wave estimates using relatively short time windows (approximately 60 min). Next, using the power of linear arrays to capture AN energy from the stationary-phase zones and AN processing techniques commonly used in DAS applications for subsurface monitoring in urban settings, we introduce a methodological approach to turn each segment of dark fiber into a short-offset monitoring array (2 km), providing redundant, hourly, surface-wave estimates. Using four days of AN data recorded by the Monterey Accelerated Research System (MARS) 20 km section offshore cable, we generate the virtual-source gathers for 10 segments spanning the whole MARS cable. We then use virtual-source data from one segment to estimate the hourly velocity changes that are then quantitatively compared with the tidal data. The results suggest that changes in seafloor seismic velocities are likely modulated by tidal height, even in regions without large tidal excursions. This advance demonstrates a new application of submarine telecom fibers for monitoring the seismic stress response of near-seafloor sediments.

A Method for Constructing an Empirical Model of Short-Term Offshore Ocean Tide Loading Displacement Based on PPP

A Method for Constructing an Empirical Model of Short-Term Offshore Ocean Tide Loading Displacement Based on PPP

Characterizing the spatial structure and aliasing effect of ocean tide loading on InSAR measurements

Ocean tide loading (OTL) displacements, shown as long-wavelength errors in Interferometric Synthetic Aperture Radar (InSAR), must be considered in large-scale applications. Despite efforts to explore the impacts of OTL on InSAR, most studies use individual interferograms and simple metrics, which fail to characterize the spatial structure of OTL. Moreover, the OTL contribution to InSAR time series remains relatively unexplored. The aliasing effect and related biases due to OTL, which are common to space-geodetic time series, are primarily theoretical with few practical observations for InSAR. This study comprehensively explores the statistical properties of OTL and their impacts on InSAR measurements, using the Southwest United Kingdom and Northwest France as study areas. Spatially, OTL artifacts on interferograms exhibit an escalating magnitude along the principal direction that aligns with the coastline's orientation. Temporally, the aliasing effect originating from OTL introduces periodic signals with prominent 15/64-day cycles into the Sentinel-1 InSAR time series, causing high velocity biases (up to ∼1 cm/yr) and uncertainties (up to ∼5 mm/yr) for short time spans. Applying OTL correction mitigates the noise level in the displacement time series, leading to a 16% improvement in accuracy, as validated against the Global Navigation Satellite System (GNSS). The study proposes the “overlapping effect” concept, which links InSAR tropospheric delay errors and OTL effects. It underscores the importance of accurate error assessment and removal. Neglecting this interaction may result in a 13% underestimation of the tropospheric error correction efficacy.

Analysis of Ocean Tide Loading Displacement Correction for Long-Strip InSAR Measurements in Coastal Areas of France

Analysis of Ocean Tide Loading Displacement Correction for Long-Strip InSAR Measurements in Coastal Areas of France

Estimation of GPS-observed ocean tide loading displacements with an improved harmonic analysis in the northwest European shelf

Estimation of GPS-observed ocean tide loading displacements with an improved harmonic analysis in the northwest European shelf

The response of borehole water levels in an ophiolitic, peridotite aquifer to atmospheric, solid Earth, and ocean tides

Peridotite aquifers are ubiquitous on Earth, but most are in the deep-sea, and thus difficult to access. Ophiolites provide a unique opportunity to study peridotite aquifers, and the Oman Drilling Project established a Multi-Borehole Observatory in a peridotite terrain of the Samail ophiolite. We use the water level response of two 400-m deep boreholes (BA1B, BA1D) to solid Earth, ocean, and atmospheric tides to investigate the hydromechanical structure of the aquifer. The two boreholes are offset by ∼ 100 m but exhibit markedly different tidal responses, indicating a high degree of short-length-scale heterogeneity. Hole BA1B does not respond to tidal strain or barometric loading, consistent with the behavior of an unconfined aquifer. Hole BA1D responds to both tidal strain and barometric loading, indicating some degree of confinement. The response to applied strain, which includes a non-negligible ocean tidal loading component, is consistent with a partially confined, low conductivity aquifer. The response to barometric loading appears to be affected by the complex hydrological structure of the surficial zone and we were not able to fit the observations to within error. Aquifer conductivity estimates for Hole BA1D based on the response to tidal strain are within a factor of ∼ 3 of pumping test estimates.

Comparison of state-of-the-art GNSS-observed and predicted ocean tide loading displacements across Australia

We seek to quantify and understand the residual signal in GPS and GLONASS estimates of ocean tide loading displacements (OTLDs) after removing state-of-the-art model estimates. To consider contributions over a broad spatial scale, we estimate OTLD over the Australian continent using sim 5.5 years of continuous GPS and GLONASS data from 360 sites. We compare these with modelled estimates, with a focus on the lunar semidiurnal M_2 and diurnal O_1 constituents. We observe spatially coherent patterns of residual OTLD in each of the east, north, and up coordinate components after the removal of tidal loading using elastic models. We subsequently assess the impact of including anelastic dispersion in the model and show a 0.2 mm reduction in range of the up component residuals at coastal sites. A similar reduction at all sites is observed in the east and north components. Of the seven ocean tide models used, we find that three recent models, FES2014b, GOT4.10c and TPXO9.v1, perform similarly, noting these comparisons are made in the CE frame. However, we show that the latter contains centre of mass (CoM) biases in amplitude up to 0.2 mm and 0.5 mm for M_2 and O_1, respectively, due to the assimilated altimetry data having not been corrected for geocentre motion. We find OTLD estimates are sensitive to the chosen orbit and clock products used in our analysis, with differences of up to 0.5 mm in the east component between solutions using the JPL and either of ESA or CODE products (GPS-only). Our analysis shows that current GNSS estimates of OTLD over Australia are typically accurate to sim 0.2 mm at which point we are unable to explain spatially coherent residuals when compared to modelled quantities. These may depend on the appropriate treatment of the CoM variation, anelasticity and/or three-dimensional Earth structure. As such, we recommend great care is taken when interpreting OTLD at the level of 0.1 or 0.2 mm, even if it is regionally coherent.

A Novel Method to Improve the Estimation of Ocean Tide Loading Displacements for K1 and K2 Components with GPS Observations

The accurate estimation of ocean tide loading displacements is essential and necessary for geodesy, oceanic and geophysical studies. It is common knowledge that K1 and K2 tidal constituents estimated from Global Positioning System (GPS) observations are unsatisfactory because their tidal periods are nearly same to the revisit cycle or orbital period of GPS constellation. To date, this troublesome problem is not fully solved. In this paper, we revisit this important issue and develop a novel method based on the unique characteristic of tidal waves to separate GPS-system errors from astronomical K1/K2 tides. The well-known credo of smoothness indicates that tidal admittances of astronomical constituents in a narrow band can be expressed as smooth functions of tidal frequencies, while the interference of GPS-system errors seriously damages the smooth nature of observed tidal admittances. Via quadratic fitting, smooth functions of tidal frequencies for tidal admittances can be determined, thus, astronomical K1 and K2 tides can be interpolated using fitted quadratic functions. Three GPS stations are selected to demonstrate our method because of their typicality in terms of poor estimates of K1/K2 tidal parameters related to GPS-system errors. After removing GPS-systematical contributions based on our method, corrected K1/K2 tides at three GPS stations are much closer to the modeled K1/K2 tides from FES2014, which is one of the most accurate tide models. Furthermore, the proposed method can be easily applied to other areas to correct GPS-system errors because their smooth nature is valid for global tidal signals.

Anelastic response of the Earth's crust underneath the Canary Islands revealed from ocean tide loading observations

SUMMARY We report on the analysis of M2 ocean tide loading (OTL) kinematic GPS vertical displacement and tidal gravity measurements using 26 GPS and four gravimetric sites across the Canary Islands archipelago. In this region, the standard deviation among recent ocean tide models is lower than 0.4 cm in amplitude and 0.3° in phase, which are suitably accurate for displacement modelling. However, for gravity we need to model regional ocean tides to achieve enough accuracy in the loading calculations. Particularly, this study improves the predicted OTL gravity variations when global ocean models are replaced with the regional model CIAM2 which assimilates local tide gauge data. These small ocean tide model errors allow us to use the differences between observed and predicted OTL values to study the elastic and anelastic properties of the solid Earth around the Canary Islands. In the prediction of OTL, we first used the recent elastic STW105 and S362ANI seismic models, obtaining average observed minus predicted residuals of 1.2–1.3 mm for vertical displacement and 3 nm s−2 for gravity. After the STW105 and S362ANI models were adjusted for anelasticity, by considering a constant quality factor Q at periods ranging from 1 s to 12.42 hr, the average misfit between observations and predicted OTL values reduced to 0.7–0.8 mm for vertical displacement and to 1 nm s−2 for gravity. However, the average vertical displacement misfit is made up from site misfits less than 0.5 mm in western islands but for the easternmost islands of Lanzarote and Fuerteventura, they still reach up to nearly 2 mm at some sites, which still exceeds the uncertainty in the GPS observations. It is hypothesized that mantle upwelling underneath the Canary Islands, creating spatial variations in the elastic properties, causes the large residuals observed in the eastern islands. We reduced the shear modulus by up to 35 per cent in the upper mantle layer of 24.4–220 km depth. This produced residual observed minus model differences of about 0.7 mm for the sites on Lanzarote and Fuerteventura, comparable to the results obtained for the GPS sites across the rest of the archipelago, whose residuals in turn were also slightly reduced through the VS velocity and shear modulus reductions (by 0.2 mm on average).

Abrupt water temperature increases near seafloor during the 2011 Tohoku earthquake

We investigated temperature records associated with seafloor pressure observations at eight stations that experienced the 2011 Mw 9 Tohoku earthquake near its epicenter. The temperature data were based on the temperature measured inside the pressure transducer. We proposed a method to estimate ambient water temperature from the internal temperature using an equation of heat conduction. The estimated seafloor water temperature showed remarkable anomalies, especially increases several hours after the Mw 9 earthquake. A station of P03 (sea depth of 1.1 km) showed an abrupt temperature increase of + 0.19 °C that occurred ~ 3 h after the earthquake, which lasted for several hours. At stations of GJT3 (sea depth of 3.3 km) and TJT1 (sea depth of 5.8 km), there were abrupt temperature anomalies of + 0.20 °C and + 0.10 °C that began to occur 3–4 h after the earthquake. These anomalies both decayed to their original levels over a few tens of days. During the decay processes, only TJT1 showed several intermittent temperature rises. A water temperature anomaly within + 0.03 °C was found up to ~ 500 m above TJT1 2 weeks after the earthquake. There was no significant anomaly at the other five stations. Processes to cause these seafloor temperature anomalies were discussed. The temperature anomaly of P03 was reasonably caused by a tsunami-generated turbidity current, as also suggested by a previous study. Meanwhile, we proposed a scenario that the abrupt temperature anomalies of GJT3/TJT1 and the intermittent anomalies of TJT1 were caused by warm water discharges from the subseafloor. The pathways of the warm water were probably composed of the branch normal fault between GJT3 and TJT1, the reverse fault near TJT1, the backstop interface, and perhaps reverse faults at the frontal prism. The proposed scenario was almost compatible with other studies based on epicentral observations. We estimated the heat properties of the initial temperature anomalies of GJT3/TJT1. The estimated heat source might be explained by that most of the geothermal fluids trapped in those fault pathways were discharged to the seafloor immediately after the earthquake. The onsets of the subsequent intermittent anomalies of TJT1 were possibly activated by low or falling ocean tidal loading.

Assessment of sub-daily ocean tide loading errors and mitigation of their propagation in multi-GNSS position time series

Assessment of sub-daily ocean tide loading errors and mitigation of their propagation in multi-GNSS position time series

A High Precision Tidal Model Based on Multisource Tidal Harmonic Constants for Offshore China

As the accuracy of analytical instruments improve, the accuracy of ocean tide load displacement (OTLD) in geodesy and ocean dynamics is becoming increasingly demanding. The method of integrating through the load Green’s function using the ocean tide model is the main means of OTLD correction. However, although different tidal models have high accuracy in open ocean regions, they are less precise and less practical in the offshore areas of China, making it difficult to correct OTLDs accurately in complicated coastline areas of China. In this work, we evaluate the accuracy of 13 different tidal models in offshore China, and construct a new tidal model, new.chinasea.2022, based on the combination of high-precision tidal harmonic parameters. The OTLD correction efficiency of new.chinasea.2022 and conventional tidal models was assessed by wRMS analysis of GPS coordinate time series from the Crustal Movement Observation Network of China (CMONOC). It turns out that (1) the newly released tidal model performs better than the old model in offshore China, and there are differences in the performance of different models for each tidal constituent in different seas; (2) The OTLD correction of new.chinasea.2022 performed better in the offshore region of China, improving the correction of FES2004 by 1%-12% and osu.chinasea.2010 by 1%-6.5%.

Tidal modulation of the seismic activity related to the 2021 La Palma volcanic eruption

The volcanic eruption at La Palma started on September 19, 2021. The eruption was preceded by a seismic swarm that began on September 11, although anomalous seismicity has been observed on the island since 2017. During the co-eruptive phase of the seismic activity, hypocenters depth was generally less than 15 km, save for the period between November 10 and November 27, when hypocenters ranged in the depth from 15 to 40 km. The eruption ended on December 13, 2021. We compute tidal stress for each earthquake at the hypocenter depth and find statistically significant correlations between the occurrence times of the earthquakes and the confining tidal stress values and stress rates. The correlation is depth-dependent, and ocean-loading tides have a stronger effect than body tides. We find that tidal stress variations contribute to the eruption onset and that certain explosive events, typical in Strombolian type volcanoes, seem to occur preferentially when the tidal stress rate is high. Our analysis supports the hypothesis that tides may modulate earthquake activity in volcanic areas, specifically during magma migration at shallow depths. A conceptual model is proposed, which could have a general application in the Canary Islands archipelago and other volcanic islands.

A superconducting gravimeter on the island of Heligoland for the high-accuracy determination of regional ocean tide loading signals of the North Sea

SUMMARY The superconducting gravimeter GWR iGrav 047 has been installed on the small offshore island of Heligoland in the North Sea approximately at sea level with the overall aim of high-accuracy determination of regional tidal and non-tidal ocean loading signals. For validation, a second gravimeter (gPhoneX 152) has been setup within a gravity gradiometer approach to observe temporal gravity variations in parallel on the upper land of Heligoland. This study covers the determination of regional ocean tide loading (OTL) parameters based on the two continuous gravimetric time-series after elimination of the height-dependent gravity component by empirical transfer functions between the local sea level from a nearby tide gauge and local attraction effects. After reduction of all gravity recordings to sea level, both gravimeters provide very similar height-independent OTL parameters for the eight major diurnal and semidiurnal waves with estimated amplitudes between 0.3 nm s−2 (Q1) and 11 nm s−2 (M2) and RMSE of 0.1–0.2 nm s−2 for 2 yr of iGrav 047 observations and a factor of 2 worse for 1.5 yr of gPhoneX 152 observations. The mean absolute OTL amplitude differences are 0.3 nm s−2 between iGrav 047 and gPhoneX 152, 0.4 nm s−2 between iGrav 047 and the ocean tide model FES2014b and 0.7 nm s−2 between gPhoneX 152 and FES2014b which is in good agreement with the uncertainty estimations. As by-product of this study, OTL vertical displacements are estimated from the height-independent OTL gravity results from iGrav 047 applying proportionality factors ${\rm d}h/{\rm d}g$ for the eight major waves. These height-to-gravity ratios and the corresponding phase shifts are derived from FES2014b. The OTL vertical displacements from iGrav 047 are estimated with amplitudes between 0.4 mm (Q1) and 5.1 mm (M2) and RMSE of 0.1–0.7 mm. These OTL amplitudes agree with FES2014b within 0.0 (M2) and 0.8 mm (K1) with a mean difference of 0.3 mm only. The OTL amplitudes from almost 5 yr of GNSS observations show deviations of up to 6 mm (M2) compared to vertical displacements from both iGrav 047 and FES2014b, which suggests systematic effects included in the estimation of OTL vertical displacements from GNSS. With the demonstrated accuracy, height-independent sensitivity in terms of gravity and vertical displacements along with the high temporal resolution and the even better performance with length of time-series, iGrav 047 delivers the best observational signal for OTL which is representative for a large part of the North Sea.

Influence of Ocean Tidal Loading on Continuous Gravity Observations in Eastern China

Global and regional ocean tide models are used to analyze the gravity effect of ocean tidal loading (OTL) for gravity stations in East China. The accuracies of OTL correction results for 21 gravity stations in East China are evaluated. The global ocean tide model is the most effective for the OTL correction of inland gravity stations (up to 90%) but is less effective for coastal gravity stations (only 60%). Considering regional ocean tide models, the applicability of OTL correction increased to 80% in coastal gravity stations. Based on the root sum square (RSS) method, among 16 combination models, the optimal combination model for OTL correction is the global model FES2014b by combing the regional model OSU.Chinasea.2010 (F14O). The RSS, which has reached 7.1 nms−2, is the minimum of the 16 combination models. Simulating with the F14O in the China Sea and adjacent areas, the gravity amplitude of the OTL is about 10 nms−2 in inland areas and > 50 nms−2 along the coastline. Especially in Southeastern China coastal areas and the southwestern coastal areas of the Korean Peninsula, the gravity amplitude of the OTL reaches about 80 nms−2. Moreover, the OTL changes drastically possibly owing to coastal topography. The results of this study provide a reference for selecting ocean tide models for high-precision analysis of continuous gravity observations in East China.

A combination constellation mode of kinematic PPP with priori constraints for determining ocean tide loading displacement

To improve the efficiency of estimation of deriving OTLD parameters with higher accuracy and take full advantage of multi-GNSS data, we investigate the potential of using global ocean tide model predictions as prior constraint for GLONASS and combined GPS+GLONASS kinematic precise point positioning (PPP), analyzing one year of GPS and GLONASS data from 20 Crustal Movement Observation Network China (CMONC) sites distributed along China coast. Seven global ocean tide models predictions are employed as prior constraint in kinematic PPP. Compared with the results of GPS-only kinematic PPP with priori information constraint, the result shows that GPS+GLONASS and GLONASS can improve the accuracy of OTLD estimates more than 40% in three components over GPS. The comparison of the effect of OTLD estimates on long-period signals in position time series shows that the correction effect of the kinematic PPP with seven different priori information constraint estimates is all as same as the reference model in three components.

Modeling the gravitational effects of ocean tide loading at coastal stations in the China earthquake gravity network based on GOTL software

Abstract The gravitational effects of ocean tide loading, which are one of the main factors affecting gravity measurements, consist of three components: (1) direct attraction from the tidal water masses, (2) radial displacement of the observing station due to the tidal load, and (3) internal redistribution of masses due to crustal deformation. In this study, software for gravitational effects of ocean tide loading was developed by evaluating a convolution integral between the ocean tide model and Green’s functions that describe the response of the Earth to tide loading. The effects of three-dimensional station coordinates, computational grid patterns, ocean tide models, Green’s functions, coastline, and local tide gauge were comprehensively considered in the programming process. Using a larger number of high-precision coastlines, ocean tide models, and Green’s functions, the reliability and applicability of the software were analyzed at coastal stations in the China Earthquake Gravity Network. The software can provide the amplitude and phase for ocean tide loading and produce a predicted gravity time series. The results can effectively reveal the variation characteristics of ocean tide loading in space and time. The computational gravitational effects of ocean tide loading were compared and analyzed for different ocean tide models and Green’s functions. The results show that different ocean tide models and Green’s functions have certain effects on the calculated values of loading gravity effects. Furthermore, a higher-precision local ocean tide model, digital elevation model, and local tidal gauge record can be further imported into our software to improve the accuracy of loading gravity effects in the global and local zones. The software is easy to operate and can provide a comprehensive platform for correcting the gravitational effects of ocean tide loading at stations in the China Earthquake Gravity Network.

The Influence of Sediments, Lithosphere and Upper Mantle (Anelastic) With Lateral Heterogeneity on Ocean Tide Loading and Ocean Tide Dynamics

AbstractOcean tide loading (OTL) and ocean tide dynamics (OTD) are known to be affected by Earth's internal structures, with the latter being affected by the self‐attraction and loading (SAL) potential. Combining the 3D earth models Lyon and LITHO1.0, we construct a hybrid model to quantify the coupled effect of sediments, oceanic and continental lithosphere, and anelastic upper mantle on OTL and OTD. Compared to PREM, this more realistic 3D model produces significantly larger vertical OTL displacement by up to 3.9, 2.6, and 0.1 mm for the M2, K1, and Mf OTL, respectively. Moreover, it shows a smaller vector difference of 0.1 mm and a smaller amplitude difference of 0.2 mm than PREM with OTL observations at 663 Global Navigation Satellite System stations, a confirmation of the cumulative effect due to these earth features. On the other hand, we find a resonant impact of wider extent and larger magnitude on OTD, especially for the M2 and K1 tides. Specifically, this impact is concentrated in the ranges 0–6 mm and 0–1.5 mm for M2 and K1, respectively, which is considerably larger than the impact on SAL (mostly in the ranges 0–2 mm and 0–1.0 mm, respectively). Since the effect on vertical displacement is at a similar level compared to the accuracy of modern data‐constrained ocean tide models that require correction of the geocentric tide by loading induced vertical displacements, we regard its consideration to be potentially beneficial in OTD modeling.

A First Reliable Gravity Tidal Model for Lake Nasser Region (Egypt)

In the framework of the French–Egyptian Imhotep Project, two spring gravimeters have been installed in the area of Lake Nasser (Egypt) with the aim to establish a first reliable gravity tide model for the region. The two tidal gravity stations are located in Aswan, on the northern edge of the lake and in Abu Simbel in the south, respectively. This study was mainly aimed to obtain a reliable model of the crustal response to tidal forces and, consequently, to increase the accuracy of the geodetic observations, to be used in future geophysical studies in this region as well as to investigate the effect of the Lake level variations on the crustal deformation and related gravity changes. Nearly 3 years of gravity records (from May 2018 to April 2021) were collected. Since no scale factor was available for the two gravimeters, the first step of this study was to achieve a reliable calibration for each of the two collected gravity signals. After removing the instrumental drift, spikes, steps and tares, both gravimeters have been calibrated by fitting the output signal against a synthetic reference signal based on the body tidal gravity response due to Wahr-Dehant Earth model and FES2014 ocean tidal loading model. The calibrated signals have been analyzed with ET34-X-V80 software for tidal analyses. This enabled us to retrieve a set of frequency-dependent gravity factors (amplitude and phase) for the main tidal waves, as well as to obtain gravity residuals. It turns out that the accuracy of the amplitude estimates for the main tidal waves is 0.2 ÷ 1% for LCR_ET16 in Aswan and 1 ÷ 10% for the LCR_D-218 in Abu Simbel. To improve the tidal model at Abu Simbel, LCR_ET16 was stopped in Aswan and relocated there. The first 90 days of gravity recordings from ET16 at Abu Simbel provide promising results, with an accuracy of the order of 0.1% for the main tidal waves, even better than the results obtained in Aswan. The residual gravity signal after tidal subtraction at Aswan is in the range of ± 50 µGal. Further analyses of the instrumental contribution are however needed before to be able to interpret this gravity signal in terms of surface loading (i.e. changes in the water level of Lake Nasser) or underground hydrology.

Study on room-temperature effect of a superconducting gravimeter prototype

PurposeThis study aims to reveal the room-temperature effect of a superconducting gravimeter prototype, which will guide its subsequent optimization to improve its gravimetric measurement accuracy.Design/methodology/approachWithout leveling, the prototype output signal, tilt data and room temperature were measured under steady operating conditions. After analyzing the correlations of the three data sets, the residuals of the prototype’s output signal were compensated using the tilt data and the geodynamic effects (ocean tide loading, atmospheric loading and the gravitational effect of polar motion) were then corrected.FindingsThe remaining residuals after correction may be caused by small tilt variations that are due to the sensor chamber temperature and radiation shield temperature changes. These small tilt variations were submerged in the tilt signal noise. Although the peak-to-peak noise of the tiltmeter does not exceed 15 µrad, it can still produce gravimetric deviations above 60 µGal when the prototype is significantly tilted.Originality/valueThis study analyzes in detail the room-temperature effect of a superconducting gravimeter prototype, introduces the tilt effect of the relative gravimeters to compensate for the gravimetric deviations and emphasizes that the improvement of fine leveling and the accuracy of the tiltmeter are key requirements for the prototype to perform high-accuracy gravity measurement tasks.