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Superconducting Gravimeter Data from Serrahn - Level 1

The International Geodynamics and Earth Tide Service (IGETS) was established in 2015 by the International Association of Geodesy (IAG). IGETS continues the activities of the Global Geodynamics Project (GGP, 1997-2015) to provide support to geodetic and geophysical research activities using superconducting gravimeter (SG) data within the context of an international network. The SG site “Serrahn” is located in the TERENO Observatory in the nort-eastern German lowlands. The observatory contributes to investigating the regional impact of climate and land use change. At the IGETS site Serrahn, the mean annual temperature is 8.8 °C and mean annual precipitation is 591 mm. The land cover is mainly characterized as a mixed forest, dominated by European beech and Scots pine. Influenced by the last glaciation in an outwash close to the terminal morraine, the uppermost soil layer of the site consists of aeolian sands up to a depth of 450 cm, followed by coarser sandy material with intercalated till layers. The unconfined groundwater level is at about 14 m below surface. There is hardly any human activity (e.g., traffic) at this quiet forest site. The nearest town is Neustrelitz at a distance of 5 km. Since December 2017, the superconducting gravimeter iGrav-033 is operated outdoors at this forest location (Latitude: 53.3392 N, Longitude: 13.17413 E, Elevation: 79.60 m). The gravimeter is installed in a dedicated field enclosure on top of a concrete pillar with an area of 1.1 m x 1.1 m at an elevation of 0.80 m above the terrain surface. The pillar has been build to a depth of 2.00 m below the surface. One additional pillar (also 1.1 m x 1.1 m, at surface level) is located right next to the iGrav installation and is used for repeated observations with absolute gravimeters (AG). At the site, meteorological (precipitation, air temperature, humidity, air pressure) and hydrological (groundwater, soil moisture, sapflow, throughfall) parameters are monitored by different sensors. Raw gravity and local atmospheric pressure records sampled at second intervals and the same records decimated at 1‐minute samples are provided as Level 1 products to the IGETS network.

Sample information, major element stream chemistry, inversion model setup and results, sample corrections for precipitation and degassing, and CO2 exchange calculations

Tables that include information and calculations associated with water samples collected from rivers in Central Italy. The goal of the project was to determine the carbon budget for the Central Apennine Mountains of Italy, by accounting for weathering reactions that are responsible for either CO2 drawdown or release into the atmosphere. The carbon budget was created by: 1) analysing samples from different water bodies and sources in the Central Apennines (rivers, lakes, and groundwater) for ion and isotope signatures, and 2) by incorporating the ion and isotope signatures from the waters into an inversion model that partitions these signatures into different sources (e.g. minerals, vegetation, atmospheric sources) around the landscape. All data associated with this publication are provided in a single excel spreadsheet that contains a separate tab for each of the 18 Tables. The supplementary data include: 1) Information on the locations of the water samples and associated water bodies, described in the “Sampling Methods” section, 2) ion and isotope measurements from the water samples, described in the “Analytical Procedure” section, 3) the setup and output from the inversion model, and 4) the CO2 calculations that form the basis for the carbon budget, described in the “Data Processing” section. Water samples were collected over two seasons, in winter and summer; data in the tables are divided by sampling season, where indicated in the content description. For a full description of the sampling strategy, data, and methods, please refer to: Erlanger et al. (2024) “Deep CO2 release and the carbon budget of the central Apennines modulated by geodynamics” Nature Geoscience.

Superconducting Gravimeter Data from Pecný - Level 2 pre-processed by station operators

The International Geodynamics and Earth Tide Service (IGETS) was established in 2015 by the International Association of Geodesy (IAG). IGETS continues the activities of the Global Geodynamics Project (GGP, 1997-2015) to provide support to geodetic and geophysical research activities using superconducting gravimeter (SG) data within the context of an international network. Raw gravity and local atmospheric pressure records sampled at second and the same records decimated at 1‐minute samples are provided as Level 1 products of the IGETS network for the Pecný station (https://doi.org/10.5880/igets.pe.l1.001). The corrected 1-minute samples have been prepared by operators of the station, from raw decimated 1-minute samples, by following steps: 1) The 1-minute samples have been used to compute residual gravity signal by using the SG calibration factor and applying corrections from tides, atmosphere and polar motion. 2) These data have been associated with auxiliary data from the SG (Dewar Pressure, Tx/Ty balance, Neck temperature etc.) and information from LOG files. 3) Gaps have been created in the residual gravity signal according to auxiliary data and log files. Moreover, gaps were created also for large disturbances, where the residual signal exceeding 20 nm/s^2. 4) Gaps up to 24 hours were filled by a linear fit. 5) Spikes exceeding 5 nm/s^2 were removed by using TSOFT. 6) Steps were applied only in exceptional cases in accordance with LOG files. 7) The cleaned residual signal was converted to corrected 1-minute samples by using the same corrections and the calibration factor as used in 1). Therefore, the corrected 1-minute signal is again in units as the raw data (Volt). Note, since 31 October 2017, the OSG-050 is running at new site (NGL - new gravimetric laboratory at Pecný) according to https://doi.org/10.5880/igets.pe.l1.001.

3D geodynamic data-driven model of the Southern Central Andes

In the southern Central Andes (~32°S), subduction of the Nazca oceanic plate beneath the South American continental plate becomes horizontal. The growth of the Altiplano-Puna Plateau is covalently related to the southward migration of the flat subduction, but the role of subduction geometry and the plate strength on current and long-term deformation of the Andes remains poorly explored. This study takes a data-driven approach of integrating the previous structural and thermal model of the lithosphere of the southern central Andes into a 3D geodynamic model to explore the different parameters contributing to the localization of deformation. We simulate visco-plastic deformation using the geodynamic code ASPECT. The repository includes parameter files and input files for the reference model (S1) and the following alternative simulations: a series of models with variation in friction at the subduction interface (S2a-d), a series of models with variation in sedimentary strength (S3a-d), a series that studies the effect of topography (S4), and a series that studies the effect of plate velocities. In addition, a readme file gives all the instructions to run them.

Digital image correlation data and orthophotos from lithospheric-scale analogue experiments of orthogonal extension followed by shortening

This dataset includes the results of 5 lithospheric-scale, brittle-ductile analogue experiments of extension and subsequent shortening performed at the Geodynamic Modelling Laboratory at Monash University (Melbourne, Australia). Here we investigated (1) the influence of the mechanical stratification of the model layers on rift basins during extension and (2) the influence of these basins on shortening-related structures. This dataset consists of images and movies that illustrate the evolution of topography (i.e., model surface height) and cumulative and incremental axial strain during the experiments. Topography and strain measures were obtained using digital image correlation (DIC) which was applied to sequential images of the model surface. This dataset also includes orthophotos (i.e., orthorectified images) of the model surface, overlain with fault traces and basins that were interpreted using QGIS. The experiments are described in detail in Samsu et al. (submitted to Solid Earth), to which this dataset is supplementary.

2D geodynamic subduction model of the Central Andes

The Central Andes (~21°S) is a subduction-type orogeny formed in the last ~50 Ma from the subduction of the Nazca oceanic plate beneath the South American continental plate. However, the most important phases of deformation occur in the last 20 Ma. Pulses of shortening have led to the sudden growth of the by the Altiplano-Puna plateau. Previous studies have provided insights on the importance of various mechanisms on the overall shortening such as the weakening of the overriding plate from crustal eclogitization and delamination, or the importance of a relatively high friction at the subduction interface, and weak sediments in foreland. However none of them has addressed the mechanism behind these shortening pulses yet. Therefore, we built a series of high resolution 2D visco-plastic subduction models using the ASPECT geodynamic code, in which the oceanic plate is buoyancy-driven and the velocity of the continent is prescribed. We have also implemented a realistic geometry for the south American plate at ~30 Ma. We propose a new plausible mechanism (buckling and steepening of the slab) as the cause of these pulses. The buckling leads to the blockage of the trench. Consequently, the difference of velocity between the South American plate and the trench is accommodated by shortening. The data presented here includes the parameters files, for the reference model (S1) and the following alternative simulations: models with variation of the friction at the subduction interface (S2a-c), a model without eclogitization of the lower crust (S3) and a model with higher thermal conductivity of the upper crust (S4). Additionally, this publication includes the initial composition and thermal state of the lithosphere used for the models and a Readme file that gives all the instructions to run them.

GphoneX Gravity Data from Hurbanovo - Level 1

The International Geodynamics and Earth Tide Service (IGETS) was established in 2015 by the International Association of Geodesy (IAG). IGETS continues the activities of the Global Geodynamics Project (GGP, 1997-2015) to provide support to geodetic and geophysical research activities using superconducting gravimeter (SG) data within the context of an international network. The Hurbanovo gravimetric observatory in southern Slovakia was established in 2019 as a part of the integrated station HUVO (GNSS permanent station and seismic station). HUVO is located on a ground floor in a small building in the vicinity of the Hurbanovo Geomagnetic Observatory, which was founded on September 30, 1900. Integration of InSAR transponder into current station architecture is also planned in 2022. The gravimetric observatory equipped with the spring gravimeter gPhoneX #108 provides continuous time-varying gravity and atmospheric pressure data. The spring gravimeter gPhoneX #108 is installed on a concrete block isolated from the rest of the building grounding. The room containing gravimeter is thermally stabilized at around 22 ± 1°C using an air conditioning unit. An additional thermal polystyrene insulation is placed around the instrument further decreasing temperature variations on its surface. Concerning signal to noise ratio, the HUVO station can be characterized as moderately noisy. The operation and maintenance of the HUVO gravimetric instrumentation is done mainly by the staff of the Slovak University of Technology. HUVO gravimetric observatory is also equipped with the accelerometer Raspberry Shake (4D) installed on the same concrete block as the spring gravimeter, operated by the staff of the Slovak Academy of Sciences. Several other meteorological sensors are also present at the site in the close vicinity of the gPhoneX #108: the meteorological station MWS 9-5, a well equipped with the ground-water level sensor and a total number of 16 sensors measuring the soil moisture. These sensors provide information necessary for modelling the gravity response associated with the variation of local hydrological masses.

Superconducting Gravimeter Data from Membach - Level 1

The International Geodynamics and Earth Tide Service (IGETS) was established in 2015 by the International Association of Geodesy (IAG). IGETS continues the activities of the Global Geodynamics Project (GGP, 1997-2015) to provide support to geodetic and geophysical research activities using superconducting gravimeter (SG) data within the context of an international network. The Membach station is located near the river Vesdre. It consists of a 130 m long gallery excavated in the side of the valley that rises to the Hautes Fagnes plateau. At the end of the gallery, there are two rooms, located at ~45 m below the ground surface. Room 1 is dedicated to absolute gravity and seismic measurements; room 2 houses the superconducting gravimeter. The structure of the gallery and the rooms is in reinforced concrete. It was built in the early 1970s to monitor the seismic activity in the vicinity of the Gileppe and Eupen water reservoirs. Works were performed contemporeanously with the raising of the Gileppe dam. The gallery has been excavated in low-porosity argillaceous sandstone with quartzitic beds. As a function of rainfall and seasonal effects, gravity variations up to 40 nms-2 have been observed, and are mostly due to groundwater changes in the vadose zone above the underground laboratory (Van Camp et al., 2006). Strong rainfall induces rapid gravity decreases (Meurers et al 2007; Delobbe et al., 2019). At the surface, a beech forest. Absolute gravity measurements have been performed on average every month since 1996, using the FG5#202 gravimeter and the station is also the reference point for the Belgian gravity network. The SG GWR#C021 has been operating continuously since 1995 August so that, since 2017 September 18, it holds both records for the longest continuous time spent measuring gravity variations in the same place and for the longest superconducting levitation of an artefact (Van Camp et al., 2017). For high precision works like Earth tides analysis on long time series, data should not be used before 1998 June 12, when the original "TIDE" card in the SG electronics was replaced by the "GGP" one. Filters are different, and so are the transfer functions. Moreover, in this early period, the SG suffered from numerous technical issues, causing several changes in the amplitude and phase calibrations and making it difficult to ensure that the data are as reliable as after 1998 June.

Superconducting Gravimeter Data from Rochefort - Level 1

The International Geodynamics and Earth Tide Service (IGETS) was established in 2015 by the International Association of Geodesy (IAG). IGETS continues the activities of the Global Geodynamics Project (GGP, 1997-2015) to provide support to geodetic and geophysical research activities using superconducting gravimeter (SG) data within the context of an international network. In 2014 December the Royal Observatory of Belgium installed the iGrav #019 at the surface site of the Rochefort "Lorette" cave laboratory. The Lorette cave is one of several cavities that belong to the Wamme–Lomme karst system, a 10 km long karst area. At the surface of the site, a small and solid building, located at the border of a large sinkhole, hosts the gravity laboratory, which is thermally stabilized at ~25°C by a heater, excepted during a few days each summer when the temperature may increase above that level. The iGrav #019 is installed directly on the bedrock (limestone) in a 1 m deep shaft. Two meters away from the iGrav there is a pillar of cement (60% sand, 40% cement, no iron nor stones) founded 1 meter deep on the bedrock and on which absolute gravity measurements are performed 10 times or more per year with the FG5#202 absolute gravimeter. See description in Fig A7 in Van Camp et al., 2017. As this instrument was installed among others to investigate flash floods in the caves, it regularly monitors sudden changes in gravity reaching 50-100 nm/s², especially during the winter (Watlet et al., 2020). This should be considered when performing e.g. tidal analyses.

Superconducting Gravimeter Data from Aubure - Level 1

The International Geodynamics and Earth Tide Service (IGETS) was established in 2015 by the International Association of Geodesy. IGETS continues the activities of the Global Geodynamics Project (GGP) between 1997 and 2015 to provide support to geodetic and geophysical research activities using superconducting gravimeter (SG) data within the context of an international network. As part of this network, the Aubure station (code AU) was established in 2017 thanks to the financial support of the EQUIPEX CRITEX (https://www.critex.fr/). Continuous time-varying gravity and atmospheric pressure data from AU are integrated in the IGETS data base hosted by ISDC (Information System and Data Centre) at GFZ. The operation and maintenance of the AU instrumentation is done by staff at EOST/ITES in Strasbourg, France. The AU station (longitude: 7.1967 E; latitude: 48.2170 N and elevation: 1151.9 m) is located in the Strengbach catchment in the Vosges mountains, a well instrumented and studied site by the Hydro-Geochemical Observatory of the Environment of Strasbourg (http://ohge.unistra.fr/). The time series of gravity and barometric pressure from iGrav 030 starts in June 2017 and is going on. The time sampling of the raw gravity and barometric pressure data of IGETS Level 1 is 1 minute. For a detailed description of the IGETS data base and the provided files see Voigt et al. (2016, https://doi.org/10.2312/GFZ.b103-16087).

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