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On-shore data of the amphibious part of the refraction-seismic project INGON in and around Sri Lanka (RV SONNE cruise SO258/2)

In July and August 2017, off-shore seismic measurements have been carried out south of Sri Lanka as part of the INGON project. Main aim of this part of the project was to study the deep structure of the continent-ocean transition south of Sri Lanka and the early plate drift of India and Sri Lanka. The marine profile was extended by 15 seismic stations on-shore Sri Lanka, of which the data is contained in this data publication (land observations of airgun sources). This dataset consists of the raw (continuous) data of the land recorders (in proprietary cube and MSEED formats) and the shot records (airgun sources) in SEGY-format (standard exchange format).

Reprocessed deep seismic reflection profile DEKORP 1990-3A (including cross-profiles Q12-Q16) across the Hessian Depression, Northwest Germany

The profile 3A was recorded in 1990 as part of the DEKORP project, the German deep seismic reflection program. The focus of the DEKORP project was on deep crustal and lithospheric structures and therefore originally not on structures at shallower depths. From today's perspective, however, this depth range is of great interest for a wide range of possible technical applications (including medium-depth and deep geothermal projects). The original data is published by Stiller et al. (2021). On behalf of the Hessian Agency of Nature Conservation, Environment and Geology (HLNUG). From the 128 km long profile 3A the southernmost 104 km (plus additional 9 km northwards with decreasing CDP coverage to avoid boundary effects during migration) were reprocessed. As a particularity, also a set of 6 cross-lines, each ca. 9.6 km in length and perpendicular to the main line, were surveyed along DEKORP 3A to get information about possible cross-dips. Five of those short cross-lines (Q12-Q16) were reprocessed in 2D and 3D as well. The focus of reprocessing of the old data was on improving the resolution / mapping of geological structures down to a depth of 6 km (approx. 3 s TWT) to describe the prolongation of faults and geological structures in more detail than in previous studies. In order to achieve these goals and in view of the fact that today's processing and evaluation methods have been improved considerably compared to the 1990‘s, a state-of-the-art reprocessing was implemented. In comparison with the original processing (Stiller et al. (2021)), more sophisticated processing steps like CRS (Common Reflection Surface) instead of CDP (Common Depth Point) stacking, turning-ray tomography and prestack time and depth migration were carried out. The reprocessing results of the DEKORP 3A survey comprise all datasets newly achieved in addition to the datasets from the original processing (Stiller et al. (2021)), i.e. (1) the migrated CRS image gathers as unstacked data, and (2) the pure CRS stack, the poststack-time as well as prestack-time and prestack-depth migrated sections as stacked data. Moreover, (3) all velocity models used for the different versions including (4) the separate first-break tomography inversion, are contained. Additionally, the results of the 2D- and 3D-reprocessing of cross-lines Q12-Q16 are included. All reprocessed data come in SEGY trace format, the final sections additionally in PDF graphic format. A reprocessing report is included as well as again all meta information for each domain (source, receiver, CDP) like coordinates, elevations, locations and static corrections combined in ASCII-tables for geometry assignment purposes. Detailed information about acquisition and reprocessing parameters can be found in the accompanying Technical Report (Stiller & Agafonova, 2022). The DEKORP 3 survey was a combined seismic survey investigating the Variscan structures of the Rhenohercynian and the Saxothuringian. Consisting of three seismic lines it starts in the Rhenohercynian Hessian Depression (DEKORP 3A), crosses the Saxothuringian Mid-German Crystalline High (DEKORP 3B/MVE (West)) and runs parallel to the northern margin of the Moldanubian (DEKORP 3B/MVE (East)). The 128 km long DEKORP 3A profile runs N-S within the Hessian Depression from the Solling Dome in the Rhenohercynian to the Vogelsberg Volcano of the Saxothuringian Mid-German Crystalline High. The middle part of the profile crosses the "Northern Phyllite Zone". The reprocessed datasets contain a sub-section of the entire profile with a total length of 104.1 km of full CDP coverage, covering the territory of the state of Hesse. The reprocessed part of 3A is intersected by five short cross-lines along the profile at km 31.75, 53.55, 73.75, 89.85, 109.85 and by DEKORP 3B/MVE (West) at km 120.75 at its southern end. The DEKORP '90-3A profile is of particular interest to investigate the seismic resolution of the crust beneath the Permo-Mesozoic to Tertiary Hessian depression, the Kassel graben structure, as well as the tertiary volcanic fields of the Reinhardswald, Habichtswald, Knüll, Söhrewald and stopping just north of the large Cenozoic Vogelsberg complex.

Reprocessed deep seismic reflection profile DEKORP 1-Laacher See Experiment 8701 across the Laacher See Volcano, East Eifel, Germany

The deep seismic reflection survey DEKORP 1-Laacher See was conducted as additional measurements in the Laacher See area in 1987 as part of the DEKORP-1 project, one main traverse of the German continental seismic reflection program. This small survey was an attempt to reveal the 3-D crustal structure in an area of the Quaternary East Eifel Volcanism and possibly find some magma chambers in the crust with high-fold near-vertical incidence vibroseis acquisition (DEKORP Research Group, 1991). The measurement consists of a 8,64 km long, multifold 2D seismic line 8701 across the Laacher See in NE-SW direction and two pseudo-3D seismic areas 8702 north of the lake and 8703 beneath the lake with one-fold coverage in each case. Laacher See or Lake Laach is a caldera lake in the Rhineland-Palatinate, Germany, one of the volcanic centres of the East Eifel Volcanic Field. It belongs together with the West Eifel to the youngest volcanic areas in Central Europe. The caldera of the Laacher See was formed about 12 900 years ago after the volcano explosively erupted, and the remaining crust collapsed into the empty magma chamber below. The Laacher See is still considered to be an active volcano, proven by seismic activities and thermal anomalies under the lake. The first processing of the Laacher See data was carried out at the Geophysical Institute of the CAU University Kiel in 1990. Unfortunately, these results have not been preserved or published. According to DEKORP Research Group (1991) the first processing resulted in poor data quality caused by high scattering and attenuation in the volcanic material near the surface. This reflected energy was not enough to image a magma chamber beneath the lake or any other structures. Thus, information about the structure of the Earth’s crust of the Eifel is mainly based on the deep seismic reflexion profile DEKORP 1B, running ca. 25 km to the west from the Laacher See und crossing DEKORP 1A at its northern profile end. In recent years, deep low‐frequency (DLF) earthquakes have been detected in the Laacher See area indicating ongoing magmatic activity in the lower crust and upper mantle (Hensch et al., 2019, Dahm et al. 2020). These and other signatures suggested the reprocessing of the Laacher See data with modern methods. Thus, the 2D seismic line 8701 has been reprocessed in 2020 within the framework of the Master’s thesis by Agafonova (2020) written at the Technical University of Berlin and supervised by the GFZ Potsdam. All reprocessed data come in SEGY trace format, the final sections additionally in PNG or PDF graphic format: as raw FF-sorted unstacked data, as preprocessed CDP-/FF-sorted unstacked data as well as poststack-time/-depth unmigrated and migrated sections. Moreover, the results of the tomographic inversion are included. Detailed information about acquisition and reprocessing parameters of line 8701 can be found in the accompanying Technical Report (Agafonova & Stiller, 2021). The reprocessed results of the Laacher See survey 1987 can be of importance for better understanding the structure of the Eifel crust. Even though significant knowledge gaps and uncertainties exist due to the insufficient data quality, such important questions can already be discussed as: • How complex is the structure beneath the Laacher See? • Can the Mantle-Crust Boundary be defined at ca. 34 km depth? • Are the strongly inclined events in the Upper Crust between 1-5 km depth parts of caldera ring-faults? • Do the reflections between 5-7 km depth indicate boundaries of a possible magma chamber?

Geophysical Imaging of Deep EarthShape (GIDES): Seismic data of the Private Reserve Santa Gracia, Chile

The dataset contains the seismic weight drop data acquired in Private Reserve Santa Gracia, Chile. The data acquisition was conducted as a part of the EarthShape project in the subproject of Geophysical Imaging of the Deep EarthShape (GIDES). The seismic line was setup to cut across an existing borehole location with core and geophysical logging data available (Krone et al., 2021; Weckmann et al., 2020). The data was acquired to image the deep weathering zone identified by the borehole data across the seismic profile. Included in the datasets are the raw data of the CUBE data logger, SEG-Y data of the recorded shots, and the shot and receiver geometry data. A vital aspect of comprehending the interplay between geological and biological processes lies in the imaging of the critical zone, located deep beneath the surface, where the transition from unaltered bedrock to fragmented regolith occurs. It had been hypothesized that the depth of such weathering zone is dependent on the climate condition of the area. A more humid climate with higher precipitation will result in a deeper weathering front. As a part of the EarthShape project (SPP-1803 ‘EarthShape: Earth Surface Shaping by Biota’), specifically the Geophysical Imaging of the Deep EarthShape (GIDES - Grant No. KR 2073/5-1), we aim to image the weathering zone using the geophysical approach. Using the seismic method, we can differentiate different weathered layers based on the seismic velocity while also providing a 2D subsurface image of the critical zone. We conducted a seismic weight drop experiment in the Private Reserve Santa Gracia, Chile, to observe the depth of the weathering zone in a semi-arid climate and compare the resulting model with existing borehole data (Krone et al., 2021; Weckmann et al., 2020). The acquired data can then be used for multiple seismic imaging techniques, including body wave tomography and multichannel analysis of surface waves.

Geophysical Imaging of Deep EarthShape (GIDES): Controlled source seismic data of Santa Gracia, Chile

The dataset contains the seismic weight drop data acquired in Private Reserve Santa Gracia, Chile. The data acquisition was conducted as a part of the EarthShape project in the subproject of Geophysical Imaging of the Deep EarthShape (GIDES). The seismic line was setup to cut across an existing borehole location with core and geophysical logging data available (Krone et al., 2021; Weckmann et al., 2020). The data was acquired to image the deep weathering zone identified by the borehole data across the seismic profile. Included in the datasets are the raw data of the CUBE data logger, SEG-Y data of the recorded shots, and the shot and receiver geometry data. A vital aspect of comprehending the interplay between geological and biological processes lies in the imaging of the critical zone, located deep beneath the surface, where the transition from unaltered bedrock to fragmented regolith occurs. It had been hypothesized that the depth of such weathering zone is dependent on the climate condition of the area. A more humid climate with higher precipitation will result in a deeper weathering front. As a part of the EarthShape project (SPP-1803 ‘EarthShape: Earth Surface Shaping by Biota’), specifically the Geophysical Imaging of the Deep EarthShape (GIDES - Grant No. KR 2073/5-1), we aim to image the weathering zone using the geophysical approach. Using the seismic method, we can differentiate different weathered layers based on the seismic velocity while also providing a 2D subsurface image of the critical zone. We conducted a seismic weight drop experiment in the Private Reserve Santa Gracia, Chile, to observe the depth of the weathering zone in a semi-arid climate and compare the resulting model with existing borehole data (Krone et al., 2021; Weckmann et al., 2020). The acquired data can then be used for multiple seismic imaging techniques, including body wave tomography and multichannel analysis of surface waves.

Crosshole seismic data at ICDP site 5068_1

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.

Seismic imaging of the overdeepened basin of Lienz (Austria)

In 2016, the Leibniz Institute for Applied Geophysics (Hannover, Germany) carried out two seismic surveys in the Lienz basin. The measurements are part of a DFG-funded project, which investigates the benefit of the application of modern multi-component reflection seismics preparatory to scientific drilling, in particular to the ICDP-project DOVE (Drilling Overdeepened Alpine Valleys). Four P-wave seismic profiles, perpendicular to the valley axes, were recorded using vibroseismic technique to gain structure and facies information. In addition, two SH-wave reflection seismics, one 6-component profile, two small 3-D layouts for P-wave and S-waves, as well as one P-wave and SH-wave refraction seismic profiles were measured for primarily methodological studies. Data show a good quality and, in a first quality control, the bedrock as well as internal structures of the basin are imaged.

Seismic investigations of clay pans in the Atacama Desert (N-Chile) (SEISCLAYPAN)

The data set was acquired in the framework of the CRC 1211 “Earth – Evolution at the dry limit” which aims to study continuous longterm (Quaternary-Miocene) paleoclimatic/environmental records from the hyperarid core of the Atacama desert / N Chile covering the last up to 10 Ma. As part of this project, three clay pans were investigated in the Coastal Cordillera (Huara 20° 4'32.75"S; 69°55'1.46"W; PAG: 21°32'27.39"S; 69°54'47.21"W; Paranal 24°29'20.53"S; 70° 8'54.63"W). The clay pans are located along a latitudinal transect across the hyperarid core of the Atacama from 20° S to 24.5° S. The seismic survey comprised a couple of crossing 2D high-resolution seismic lines per each of the clay pans, acquired with vertical component geophones, Geode recorders and a PEG-40 accelerated weight drop as source.

A database of physical experiments, fieldwork information, and a seismic line applied on the eastern Domeyko Cordillera, northern Chile

This dataset contains a series of analog models for comparing and testing positive tectonic inversion mechanisms and wedge structure formation. Furthermore, it includes a 2-D seismic reflection profile that can be compared with the models presented here. Finally, several photos of some structural features that cab be associated with wedge structure are shown. Both seismic lines and photos are located on a segment of Andean forearc, specifically, in the eastern Domeyko Cordillera and the Salar de Atacama Basin in northern Chile. Specifically, the models were deformed under extensional and compressional conditions, inducing a positive tectonic inversion, using a pure/simple-shear deformational apparatus. Our models intended to simulate the tectonic conditions presented in López et al. (2022), which illustrated the structural setting of the Domeyko Cordillera as resulting from the interplay between positive inversion tectonics and pure shortening faulting. Moreover, our models simulated three geological environments that developed sequentially through time: (a) syn-rift sedimentation, (b) post-rift and pre-shortening sedimentation, and (c) syn-shortening sedimentation. Post-rift and syn-shortening sedimentation incorporated a ductile layer (PDMS) during the shortening phase, simulating the presence of evaporitic deposits (i.e., gypsum) to test the conditions that could have controlled the formation of pure-shortening-related structures in the case study under consideration.

A 70 3-component sensor deployment to monitor the 2020 EGS stimulation in Espoo/Helsinki, southern Finland - Dataset

The stations are part of a seismic network in the Helsinki capital area of Finland in 2020. The stations recorded the response to a second stimulation of a ∼ 6 km deep enhanced geothermal system in the Otaniemi district of Espoo that followed on the first larger stimulation in 2018. The second stimulation from 6 May to 24 May 2020 established a geothermal doublet system. The Institute of Seismology, University of Helsinki (ISUH), installed the 70 GIPP-provided geophones in addition to surface broadband sensors, ISUH-owned short-period instruments, and a borehole satellite network deployed by the operating company. The data set consists of raw CUBE-recorder data and converted MSEED data. The data set has been collected to underpin a wide range of seismic analysis techniques for complementary scientific studies of the evolving reservoir processes and the induced event properties. These should inform the legislation and educate the public for transparent decision making around geothermal power generation in Finland. The full 2020 network and with it the deployment of the CUBE stations is described in a Seismological Research Letter Data Mine Column by A. Rintamäki et al. (2021).

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