Other language confidence: 0.9883020666101121
This data set contains pressure and flow measurements of the GEOREAL hydraulic injection experiment at the KTB pilot borehole (KTB-VB) in December 2023. The experiment aimed at stimulating the crystalline rock mass and monitoring induced seismicity in near real-time. However, there was no induced seismicity recorded. During 6 to 15 November 2023 a volume of 600 m³ of fresh water was injected through a stuck packer in the cased borehole pressurizing the entire KTB-VB including the open-hole section at the depth interval of 3,850-4000 m. Flow rates ranged between 10 and 220 l/min. Flow and pressure are provided from 9 Nov onwards, when injection was nearly continuous and initial tests with the pumps were finished. Largest flow rates were achieved between 12 to 14 Nov of up to 225 l/min and wellhead pressures of 300 bar (see Figures below). There were two hydraulic pumps used, one manual pump (MCPS) for low flow rates and another named HPS for large flow rates. A data gap in the pressure data exists between 12 Nov 10 am and 12 Nov 5:56 pm.
The dataset contains source parameters of acoustic emission (AE) events recorded during triaxial friction (stick-slip) experiments performed on the Westerly Granite sample WgN05. In addition we provide raw waveform data of AE events recorded in triggered mode with a network of 16 AE sensors. Basic seismic catalog associated with the stick-slip experiment contains origin time, hypocentral location in local Cartesian coordinate system of the sample (with associated uncertainties), and AE-derived magnitude. In addition, for a subset of AEs we provide full moment tensors. This catalog include information on fault parameters (strike, dip and rake of the two nodal planes), percentage of isotropic, compensated linear vector dipole and double-couple components of the full moment tensor, P, T, B axes orientations in the coordinate system of the sample, uncertainty assessment, as well as the six independent moment tensor components. Finally, we provide a time series of axial stress values as presented in the Kwiatek et al. (2023) as well as the coordinates of the AE sensors. The catalog and parametric data is supplemented with the raw waveform recordings stored in HDF5 format from 16 acoustic emission sensors placed on the surface of the sample.
This seismic crosshole dataset was acquired in the context of the DOVE project (Drilling Overdeep-ened Alpine Valleys) at ICDP site 5068_1 (Tannwald Basin) to image the glacial sediments at sub-meter scale. It consists of the field data with geographical coordinates. The project aims to investigate the landscape evolution in the Alpine region by drilling overdeep-ened valleys and analyzing the cores (DOVE-Phase 1 Scientific Team, Schaller et al., 2023, Schuster et al., 2024). At site 5068_1 (Tannwald Basin), three boreholes were drilled to a depth of about 160 m depth, reaching the bedrock. Boreholes 5068_1_A and 5068_1_B were flush drilling and bore-hole 5068_1_C was cored. In 2022, the boreholes were used to perform high-resolution crosshole seismic measurements in order to image the glacial sediments at sub-meter scale. This dataset con-sists of the seismic field data with geographical coordinates and is subdivided by (1) the used source and receiver borehole equipment (P: sparker and 24-station hydrophone string, SV: vertically polarizing shear wave source and three-component geophone string with eight geophones, SH: horizontally polarizing shear wave source and three-component geophone string with eight geophones), (2) the respective borehole plane (BA, BC, and AC), and (3) the acquisition geometry (STRING, CIRCLE, LINE_BA, LINE_BC, LINE_AC). The surface seismic data (CIRCLE, LINE_BA, LINE_BC, LINE_AC) was recorded by three-component geophones. The seismic data is provided in SEGY Rev. 1.0 format together with geometry files in csv-format.
For the safe and sustainable use of deep geothermal wells, construction must proceed as intended. An integer well ensures that all fluids within the borehole are always under control. One of the most critical steps is the cementing of the casings. Despite extensive experience in the petroleum industry, challenges with well integrity are a worldwide phenomenon. One reason could be that conventional measurement methods can only verify the success of cementing once the cement job has been completed. In contrast, distributed fiber optic sensing methods can monitor the entire cementing process along the entire drilling path. This data set contains the results of the Distributed Temperature Sensing (DTS) and the derived product "vibrational energy" of a Distributed Dynamic Strain Sensing (DDSS or DAS) of the whole cementing process. We collected this data during the primary cementing of an injection well's 874m surface casing at the geothermal site Schäftlarnstr, Munich. We measured the cement placement and 24 hours of the early hydration. We obtained the data with a fiber optic cable permanently deployed behind the casing. The cable contained Multi-Mode fibers (for DTS) and Single-Mode fibers (for DAS). Table 1 in the data description document shows the units used and the key parameters of our measurement. In the first step, we allocated each channel to its depth in the borehole. We used a cold spray (for DTS) and a tap test (for DAS) to locate the entry to the borehole. To obtain the vibrational energy of the DAS data, we summarized the raw dynamic strain with a Root Mean Square (RMS) in a window of 60 seconds. We calculated the vibrational energy for a wide range of different frequency ranges (Butterworth bandpass). The data are provided in csv formats and further explained in the data description document. Acknowledgement: GFK-Monitor is funded by the Federal Ministry for Economic Affairs and Climate Action via the Project Management Jülich (PTJ) (funding code: 03EE4036, project duration: July 1, 2022 - June 30, 2025). The fiber optic infrastructure was provided by GAB (Geothermie Allianz Bayern): Funded by: Bayerisches Staatsministerium für Wissenschaft und Kunst (Hauptgebäude: Salvatorstraße 2, 80333 München).
In 2020 and 2021 the STIMTEC-X hydraulic stimulation experiment was performed at ca.~130 m below surface at the Reiche Zeche underground research laboratory in Freiberg, Saxony/Germany. The project temporally followed the STIMTEC experiment at the same site and aimed at understanding the stress heterogeneity of the anisotropic and metamorphic gneiss rock mass. The STIMTEC-X experiment applied the hydraulic stimulation technique in several boreholes at the mine-scale. Complementary to the stimulations, there were active seismic ultrasonic transmission data acquired before the stimulations. We use a seismic monitoring network consisting of six single-component acoustic emission (AE) sensors (sensitivity 1-60 kHz), six hydrophone-like AE sensors (sensitivity 1-40 kHz) and four to twelve single-component Wilcoxon accelerometers (sensitivity 50 Hz-25 kHz). The AE sensors and remained stationary in sub-horizontal and upwards reaching boreholes, the accelerometers were mostly installed along the tunnel walls with one accelerometer in a shallow borehole in each tunnel, and the hydrophone-like AE sensors were installed in the down-going water filled boreholes, but repositioned for each measurement campaign (Figure 1). This data set of 120 active ultrasonic transmission (UT) measurements is supplementary to Boese et al. (2022, in review), which introduces some of the active measurement campaigns of the STIMTEC-X experiment in detail. The whole data set togetter with the “Ultrasonic transmission measurements from six boreholes from the STIMTEC experiment, Reiche Zeche Mine, Freiberg (Saxony, Germany)” [https://doi.org/10.5880/GFZ.4.2.2021.002] was used to evaluate performance measures such as sensitivity and frequency bandwith, coupling, placement and polarity of the hydrophone-like AE sensor compared to AE sensors. The active seismic data provided here are from seven boreholes (BH01, BH05, BH06, BH10, BH14, BH18, BH19) as shown in Figure 1. There are nine tables provided as metadata of which seven contain the STIMTEC-X sensor coordinates for each measurement campaign, the event information of all the 120 UT measurements and the UT picks. The UT measurements were recorded with a sampling rate of 1 MHz and results from an automatic stack of 1024 UT pulses generated by the ultrasonic transmitter and recorded by the STIMTEC-X sensors. The UT measurements are saved in binary file format (fsf file format). Fsf-files can be processed with FOCI software: https://www.induced.pl/software/foci. Each fsf file contains 32768 samples, which corresponds to 0.032768 seconds. All UT event files were manual inspected and phase arrivals identified. These are stored in the fsf-file header as well as in the table STIMTECX_UT_picks.csv.
The GFZ-Landsvirkjun Theistareykir Fibre array is located in the Theytareykir geothermal area, in North Iceland. It is collocated with arrays of broadband seismometers and gravity meters (see e.g., https://doi.org/10.1186/s40517-021-00208-w). The geometry of the fibre array is following the telecom network in the area, and was chosen to test the seismological capabilities of telecom cables in this geothermal environment. We connected an iDAS V2 interrogator from Silixa. The interrogator location is lat=65.898041, lon=-16.966274. The array starts N-S and after 1.5 km, turns towards the East, up to a local transmission antenna station for mobile phones. The length of the path is ~5 km. The length of the cable is actually more than 15 km, as other fibre instance is connected at the transmission antenna station.. Jumps were performed along the cable to geo-locate the channels. The exact location of the fibre can unfortunately not be disclosed. Original recordings at 1000 Hz were downsampled to 200 Hz using a software from INGV-OE (michele.prestifilippo@ingv.it) and are provided in an h5 format. We provide here the first fibre instance (5 km long). The data contain 1 h long recording intervals framing M>5 teleseismic earthquakes recorded in the frame of the global DAS month, an initiative to collaboratively record and share simultaneously recorded DAS data from all over the world (https://www.norsar.no/in-focus/global-das-monitoring-month-february-2023). DAS is an emerging technology increasingly used by seismologists to convert kilometer long optical fibers into seismic sensors.
We perform a teleseismic P-wave travel-time tomography to examine the geometry and structure of subducted lithosphere in the upper mantle beneath the Alpine orogen. The tomography is based on waveforms recorded at over 600 temporary and permanent broadband stations of the dense AlpArray Seismic Network deployed by 24 different European institutions in the greater Alpine region, reaching from the Massif Central to the Pannonian Basin and from the Po plain to the river Main. Teleseismic travel times and travel-time residuals of direct teleseismic P-waves from 331 teleseismic events of magnitude 5.5 and higher recorded between 2015 and 2019 by the AlpArray Seismic Network are extracted from the recorded waveforms using a combination of automatic picking, beamforming and cross-correlation. The resulting database contains over 162.000 highly accurate absolute P-wave travel times and travel-time residuals. For tomographic inversion, we define a model domain encompassing the entire Alpine region down to a depth of 600 km. Predictions of travel times are computed in a hybrid way applying a fast Tau-P method outside the model domain and continuing the wavefronts into the model domain using a fast marching method. We iteratively invert demeaned travel-time residuals for P-wave velocities in the model domain using a regular discretization with an average lateral spacing of about 25 km and a vertical spacing of 15 km. The inversion is regularized towards an initial model constructed from a 3D a priori model of the crust and uppermost mantle and a 1D standard earth model beneath. The resulting model provides a detailed image of slab configuration beneath the Alpine and Apenninic orogens. Major features are a partly overturned Adriatic slab beneath the Apennines reaching down to 400 km depth still attached in its northern part to the crust but exhibiting detachment towards the southeast. A fast anomaly beneath the western Alps indicates a short western Alpine slab whose easternmost end is located at about 100 km depth beneath the Penninic front. Further to the east and following the arcuate shape of the western Periadriatic Fault System, a deep-reaching coherent fast anomaly with complex internal stucture generally dipping to the SE down to about 400 km suggests a slab of European origin limited to the east by the Giudicarie fault in the upper 200 km but extending beyond this fault at greater depths. In its eastern part it is detached from overlying lithosphere. Further to the east, well-separated in the upper 200 km from the slab beneath central Alps but merging with it below, another deep-reaching, nearly vertically dipping high-velocity anomaly suggests the existence of a slab beneath the Eastern Alps of presumably the same origin which is completely detached from the orogenic root. The data are fully described in Paffrath et al. (2021). The model is provided as tabular data with six columns (1) Longitude (deg), (2) Latitude (deg), (3) Depth (km), (4) vp (km/s), (5) dVp (%), (6) Resolution.
This dataset is supplementary material to "What controls the presence and characteristics of aftershocks in rock fracture in the lab?" by Joern Davidsen, Thomas H. W. Goebel, Grzegorz Kwiatek, Sergei Stanchits, Jordi Baro and Georg Dresen (Davidsen et al., 2021). The dataset contains source parameters of acoustic emission events recorded during triaxial fracture and friction (stick-slip) experiments performed on two Westerly Granite samples, Aue Granite and Flechtigen Sandstone. Basic seismic catalog associated with each experiment contains origin time, hypocentral location in local Cartesian coordinate system of the sample, acoustic-emission derived magnitude and polarity coefficient (a simplified measure of mechanism type: shear, pore opening or collapse). Extended catalog information is available for selected experiments including information whether event is background seismicity, trigger of following events or triggered by preceding events. In addition, we provide information on focal mechanisms calculated in each experiment using full moment tensor inversion. Focal mechanism catalogs include information on strike, dip and rake of two nodal planes, and percentage of isotropic, clvd and double-couple components of the full moment tensor. The detailed description of catalog is provided in the data description file which is also included in the zip folder of the data.
An extensive vertical seismic profiling (VSP) survey using wireline distributed acoustic sensing (DAS) technology was carried out between the 15th and 18th of February 2017 at the geothermal in-situ laboratory Groß Schönebeck, Germany. Borehole measurements were recorded in two 4.3 km deep wells E GrSk 3/90 and Gt GrSk 4/05. Two hybrid fibre optics cables were freely lowered inside the wells to form dense receiver arrays. As a seismic source, four heavy vibroseis trucks were used. The survey consisted of 61 source positions distributed in a spiral pattern around the target area. This data publication consists of raw uncorrelated seismic data acquired for 3D seismic imaging purposes. Supplementary information such as well trajectories, source point coordinates, and the pilot sweep data is also provided. Data related to zero-offset measurements can be found in Henninges et al. (2021, https://doi.org/10.5880/GFZ.4.8.2021.001). Further details on the survey design and data acquisition parameters can be found in Henninges et al. (2021, https://doi.org/10.5194/se-12-521-2021); Martuganova et al. (2021, 2022). Information on high-resolution 3D reflection seismic acquisition campaign carried out at Groß Schönebeck in February–March 2017 can be found in Krawczyk et al. (2019); Bauer et al. (2020); Norden et al. (2022). The 3D DAS VSP processing workflow, 3D DAS imaging results, and comparison with 3D surface seismics are presented in Martuganova et al. (2022).
This data publication contains vertical seismic profiling (VSP) data collected at the Groß Schönebeck site, Germany, from February 15-18, 2017. Energy excitation was performed with vibrator sources. Data was acquired in the two4.3 km deep wells E GrSk3/90 and Gt GrSk4/05 (in the following referred to as GrSk3 and GrSk4) using hybrid wireline fiber-optic sensor cables and distributed acoustic sensing (DAS) technology. In total, data for 61 source positions (VP1-VP76) distributed in a spiral-shaped pattern with offsets between 180 m and 2000 m from the wellheads was collected. The data publication covers selected common source gathers for a zero-offset position and representative examples for three intermediate-and far-offset positions, in the form of full waveform data stored in SEG-Yformat. Both uncorrelated raw data and data for different processing stages described in Henninges et al. (2021)are given. Moreover, the survey geometry data (well trajectories and source point coordinates), the pilot sweep data, records of a conventional three-component borehole geophone, and processing results for the VP10 zero-offset position (vertical one-way travel times, interval velocities, corridor stacks) are included. Further information on the survey design and data acquisition, the overall characteristics of the acquired data, and the zero-offset data processing and evaluation for the VP10 source position are described in Henninges et al. (2021)
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