245 documents found in 417ms
# 1
Yan, Rui • Woith, Heiko • Wang, Rongjiang • Wang, Guangcai
Abstract: A high-fidelity radon record covering nearly 40 years from the hot spring site of BangLazhang (BLZ), Southwestern China allows to study multi-year periodicities. At BLZ, radon dissolved in water (Radon), water temperature (WT), and spring discharge rate (DR) were measured daily from 1976 until 2015. Barometric pressure, regional rainfall, galactic cosmic rays (GCR flux is modulated by solar wind and thus a proxy for solar activity), and regional seismicity from the same period were considered to identify potentially influencing factors controlling the changes in radon [Yan et al., 2017]. Various wavelet techniques indicate that the long-period radon concentration is characterized by a quasi-decadal (8-11 years) cycle, matching well with the concurrent periodicity in water temperature, spring discharge rates. The BLZ hot spring monitoring site is maintained and operated by the China Earthquake Administration of Yunnan Province. Water from the spring is sampled once daily and measurements of radon have been performed routinely in a laboratory since 1976 April 6. The sample time is designated to occur at 8 o’clock in the morning in order to reduce the effect of daily variations. The radon concentration has been measured with three types of radon measurement instruments during the past 40 years. From 1976 April 6, to 1982 June 5, a FD-105 type radon gas detector was used, reporting the radon concentration in Eman. Eman is converted to the metric unit Bq/L using the relationship 1 Eman = 3.7 Bq/L. From 1982 June 6 to 2012 April 11, a FD-105K type electrometer (manufactured by Shanghai Electronic Instrument, co.) was used, the measurements given in Bq/L. Since 2012 April 12, a FD-125 type Radon & Thorium analyzer, manufactured by Beijing Nuclear Instrument Factory, sponsored by CNNC (China National Nuclear Corporation), has been used. Water sampled from the spring is degassed by bubbling air and transported into a chamber, where the radon concentration is measured in a ZnS cell connected to a photomultiplier detector, and a scintillation counter. The measurement precision of the instruments is 0.1 Bq/L. A solid radium source (226Ra) with a known radioactive radon content is used for the calibration of the water radon under normal working conditions. This source is used to measure and calculate the calibration value of the instrument. In addition to radon, water temperature and spring discharge rate are measured at the spring site when the water is sampled for radon. Temperature is measured using a mercury thermometer with a resolution of 0.1°C. Discharge rate is measured using the stopwatch capacity method, i.e., the required time per unit volume of water is measured. Barometric pressure has been measured since 1997. Regional rainfall data were downloaded through the CPC Merged Analysis of Precipitation (CMAP) for the same period to evaluate its possible influence on radon in the present study.
# 2
Borg, Erik • Maass, Holger • Renke, Frank • Jahncke, Dirk • Stender, Vivien • (et. al.)
Abstract: This data collection compiles the climate stations of the DEMMIN test site operated by the National Ground Segment Neustrelitz (Remote Sensing Data Center, German Aerospace Center DLR) in cooperation with GFZ German Research Centre for Geosciences (GFZ). The site was originally installed by the DLR in 2000 and has become part of the TERENO Northeastern German Lowland Observatory in 2011. This data collection only comprises the DLR climate stations. Climate and soil moisture stations operated by GFZ are published as separate data compilations (Itzerott et al., 2018, 2018). The DEMMIN test site is located within the central monitoring sites of the TERENO Northeastern German Lowland Observatory. It covers 900 km² and exhibits mostly glacial formed lowlands with terminal moraines in the southern part, containing the highest elevation of 83m a.s.l. The region between the rivers Tollense and Peene consists of flat ground moraines, whereas undulating ground moraines determine the landscape character north of the river Peene. The lowest elevation is located near the town Loitz with 0.5m a.s.l. The region is characterized by intense agricultural use and the three rivers Tollense and Trebel which confluence into the Peene River at the Hanseatic city Demmin. The present climate is characterized by a long-term (1981–2010) mean temperature of 8.7 °C and mean precipitation of 584 mm/year, measured at the Teterow weather station by Deutscher Wetterdienst (DWD). The Northeastern German Lowland Observatory is situated in a region shaped by recurring glacial and periglacial processes since at least half a million years. Within this period, three major glaciations covered the entire region, the last time this happened approximately 25-15 k ago (Weichselian glaciation). Since that time, a young morainic landscape developed characterized by many lakes and river systems that are connected to the shallow ground water table. The test site is instrumented with more than 40 environmental measurement stations (DLR, GFZ) and 63 soil moisture stations (GFZ). A lysimeter-hexagon (DLR, FZJ) was installed near to the village Rustow and is part of the SOILCan project. A crane completes the measurement infrastructure currently available in the test site installed by GFZ/ DLR in 2011. Data is automatically collected via a telemetry network by DLR. The quality control of all environmental data is carried out by DLR using visual inspection and automatic quality processing is performed by GFZ since 2012. The delivered dataset contains the measured data and quality flags indicating the validity of each measured value and detected reasons for exclusion. The dataset is also available through the TERENO Data Discovery Portal. The dataset will be dynamically extended as more data is acquired at the stations. New data will be added after a delay of several months to allow manual interference with the quality control process. The TERENO (TERrestrial ENvironmental Observatories) is an initiative of the Helmholtz Centers (Forschungszentrum Jülich – FZJ, Helmholtz Centre for Environmental Research – UFZ, Karlsruhe Institute of Technology – KIT, Helmholtz Zentrum München - German Center for Environmental Health – HMGU, German Research Centre for Geosciences - GFZ, and German Aerospace Center – DLR) (http://www.tereno.net/overview-de)..TERENO spans an Earth observation network across Germany that extends from the North German lowlands to the Bavarian Alps. This unique large-scale project aims to catalogue the longterm ecological, social and economic impact of global change at regional level.
# 3
Blanke, Aglaja • Kwiatek, Grzegorz • Martínez-Garzón, Patricia • Bohnhoff, Marco
Abstract: This data set is supplementary to the BSSA research article of Blanke et al. (2019), in which the local S-wave coda quality factor at The Geysers geothermal field, California, is investigated. Over 700 induced microseismic events recorded between June 2009 and March 2015 at 31 short-period stations of the Berkeley-Geysers Seismic Network were used to estimate the frequency-dependent coda quality factor (Q_C) using the method of Phillips (1985). A sensitivity analysis was performed to different input parameters (magnitude range, lapse time, moving window width, total coda length and seismic sensor component) to gain a better overview on how these parameters influence Q_C estimates. Tested parameters mainly show a low impact on the outcome whereas applied quality criteria like signal-to-noise ratio and allowed uncertainties of Q_C estimates were found to be the most sensitive factors. Frequency-dependent mean-Q_C curves were calculated from seismograms of induced earthquakes for each station located at The Geysers using the tested favored input parameters. The final results were tested in the context of spatio-temporal behavior of Q_C in the reservoir considering distance-, azimuth and geothermal production rate variations. A distance and azimuthal dependence was found which is related to the reservoir anisotropy, lithological-, and structural features. By contrast, variations in geothermal production rates do not influence the estimates. In addition, the final results were compared with previous estimated frequency-independent intrinsic direct S-wave quality factors (Q_D) of Kwiatek et al. (2015). A match of Q_D was observed with Q_C estimates obtained at 7 Hz center-frequency, suggesting that Q_D might not be of an intrinsic but of scattering origin at The Geysers. Additionally, Q_C estimates feature lower spreading of values and thus a higher stability. The Geysers geothermal field is located approximately 110 km northwest of San Francisco, California in the Mayacamas Mountains. It is the largest steam-dominated geothermal reservoir operating since the 1960s. The local seismicity is clearly related to the water injections and steam production with magnitudes up to ~5 occurring down to 5 km depth, reaching the high temperature zone (up to 360°C). The whole study area is underlain by a felsite (granitic intrusion) that shows an elevation towards the southeast and subsides towards northwest. A fracture network induces anisotropy into the otherwise isotropic rocks featuring different orientations. Moreover, shear-wave splitting and high attenuating seismic signals are observed and motivate to analyze the frequency-dependent coda quality factor. Two data sets were analyzed: one distinct cluster located in the northwest (NW) close to injection wells Prati-9 and Prati-29, and the other one southeast (SE) of The Geysers, California, USA, close to station TCH (38° 50′ 08.2″ N, 122° 49′ 33.7″ W and 38° 46′ 59.5″ N, 122° 44′ 13.2″ W, respectively). The frequency-dependent coda quality factor is estimated from the seismic S-wave coda by applying the moving window method and regression analysis of Phillips (1985). Different input parameters including moving widow width, lapse time and total coda length are used to obtain Q_C estimates and associated uncertainties. Within a sensitivity analysis we investigated the influence of these parameters and also of magnitude ranges and seismic sensor components on Q_C estimates. The coda analysis was performed for each event at each sensor component of each station. The seismograms were filtered in predefined octave-width frequency bands with center-frequencies ranging from 1-69 Hz. The moving window method was applied starting in the early coda (after the S-onset) for each frequency band measuring the decay of Power Spectral Density spectra. The decay of coda amplitudes was fitted with a regression line and Q_C estimates were calculated from its decay slope for each frequency band. In a final step a mean-Q_C curve was calculated for each available station within the study area resulting in different curves dependent on event location sites in the northwest and southeast. Data Description The data contain final mean-Q_C estimates of the NW and SE Geysers, coda Q estimates at 7 Hz center-frequency calculated by using the NW cluster, and initial direct Q estimates of Kwiatek et al. (2015) using the same data of the NW cluster. Table S1 shows final mean coda quality factor estimates obtained from the NW cluster at injection wells Prati-9 and Prati-29. The column headers show stations (station), center-frequencies of octave-width frequency bands in Hertz (f[Hz]), mean coda Q estimates (meanQc) and related standard deviations (std), all obtained by coda analysis. Table S2 shows the final mean coda quality factor estimates obtained from additional selected 100 events in the SE Geysers. Column headers correspond to those in Table S1. Table S3 shows coda Q estimates related to 7 Hz center-frequency. The column headers show stations (station), center-frequency of octave-width frequency bands in Hertz (f[Hz]), coda Q estimates at 7 Hz center-frequency (Q_C) and related standard deviations (std2sigma; 95% confidence level), all obtained by coda analysis. Table S4 shows selected direct S-wave quality factors of Kwiatek et al. (2015) obtained by spectral fitting. The column headers show stations (station) and direct S-wave Q estimates (Q_D). The four tables are provided in tab separated txt format. Tables S3 and S4 are used for a comparative study and displayed in Figure 12 of the BSSA article mentioned above.
# 4
Pick, Leonie • Korte, Monika
Abstract: The HMC (Hourly Magnetospheric Currents) index measures the activity of large-scale magnetospheric currents on Earth's surface from 1900 to 2015. It resolves the absolute intensity of low-frequency variations, especially at periods relevant to the solar cycle, more robustly than existing geomagnetic indices. HMC is based on hourly means of vector magnetic field measurements from 34 mid latitude geomagnetic observatories obtained from WDC Edinburgh (http://www.wdc.bgs.ac.uk/catalog/master.html). This data has been manually revised to correct for spikes, jumps and drifts. A detailed description of the derivation method is given in Pick et al., 2018 to which these data are supplementary material. This directory contains the HMC index (hmc1900phor.hor) and the modified observatory data that it is based on (data.zip). The index and the observatory data files are formatted in compliance with the IAGA-2002 ASCII exchange format (https://www.ngdc.noaa.gov/IAGA/vdat/IAGA2002/iaga2002format.html). Individual file names are composed of:[IAGA code of observatory] + [first active year during 1900-2015] + [p(provisional)] + [hor(hourly)] + [_mod(modified)].hor Also included is information on how the data modifications (list in modifications.pdf) were applied (readme.txt).
# 5
Corbi, Fabio • Sandri, Laura • Bedford, Jonathan • Funiciello, Francesca • Brizzi, Silvia • (et. al.)
Abstract: This data set includes the results of digital image correlation of one experiment on subduction megathrust earthquakes with interacting asperities performed at the Laboratory of Experimental Tectonics (LET) Univ. Roma Tre in the framework of AspSync, the Marie Curie project (grant agreement 658034) lead by F. Corbi in 2016-2017. Detailed descriptions of the experiments and monitoring techniques can be found in Corbi et al. (2017 and 2019) to which this data set is supplementary material. We here provide Digital Image Correlation (DIC) data relative to a 7 min long interval during which the experiment 
produces 40 seismic cycles with average duration of about 10.5 s (see Figure S1 in Corbi et al., 2019). The DIC analysis yields quantitative about the velocity field characterizing two consecutive frames, measured in this case at the model surface. For a detailed description of the experimental procedure, set-up and materials used, please refer to the article of Corbi et al. (2017) paragraph 2. This data set has been used for: a) studying the correlation between apparent slip-deficit maps and earthquake slip pattern (see Corbi et al., 2019; paragraph 4); and b) as input for the Machine Learning investigation (see Corbi et al., 2019; paragraph 5). Further technical information about the methods, data products and matlab scripts is proviced in the data description file. The list of files explains the file and folder structure of the data set.
# 6
Förster, Hans-Jürgen • Walsh, Nathanial John
Abstract: This data set is the third of a series reporting chemical data for accessory minerals from felsic igneous rocks. It compiles the results of electron-microprobe spot analyses of monazite-(Ce) from various Paleoproterozoic granitoids and spatially associated gneisses located in the wider Fort McMurray area in northeastern Alberta, Canada. The data were generated in connection with the Master of Science thesis of Nathanial John Walsh (Walsh 2013) at the Department of Earth and Atmospheric Sciences of the University of Alberta, Edmonton, Canada, but remained unpublished. The thesis was part of the Helmholtz - Alberta - Initiative (HAI) between the University of Alberta and the Helmholtz Association. Interestingly, monazite from the diverse basement rocks display various kinds of pattern with respect to composition and origin. The great bulk of measured grains display variably declined chondrite-normalized LREE patterns virtually free of anomalies indicative for significant fluid-induced overprinting. We have rocks characterized by largely unzoned, chemically homogeneous grains. There are as well rocks containing nicely patchy-zoned grains showing a wide range in composition, in particular regarding the Th/LREE proportions. Here, maximum measured Th concentration amounted to 33 wt% ThO2. Incorporation of Th into the crystal structure is almost exclusively governed by the huttonite substitution reaction, i.e., Th^4+ + Si^4+ = REE^3+ + P^5+, as characteristic for this chemical type of granites (Förster 1998). The suite of rocks also included samples containing small-sized inclusions of Th-poor monazite in apatite, which formed in response to metamorphic, fluid-aided dissolution-reprecipitation processes (Harlov and Förster 2003, Harlov et al. 2005). Finally, we have a quartz monzonite containing Th-poor monazite in apatite together with matrix monazite of normal Th concentration, the origin if which is not yet fully resolved (cf. Foerster-2018-004_monazite-alberta-BSE images.pdf. presenting back-scattered electron images of monazite grains). In brief, the data set provides information on several aspects of formation and alteration of monazite in non-metamorphic and metamorphic granite. The data set published here contains the complete pile of data acquired for monazite-(Ce) and back-scattered electron (BSE) images of many of the probed grains. Chemical data are provided as Excel and machine-readable .csv files, which contain the information listed in Table 1 of the data description file. Column headers in red (only in the Excel version) indicate that the data and information provided in these columns is from Walsh (2013). “0.00” means that the concentrations of the respective elements were measured, but were below their limits of detection. Blank boxes in oxide concentrations columns indicate that the respective elements were not sought. The collection of BSE images is presented as pdf.file. The sample and grain numbers are given below each mineral image and are corresponding to the Sample No. and the Grain No. in the data table. The thesis of N. Walsh "Walsh, N.J. (2013) Geochemistry and geochronology of the Precambrian basement domains in the vicinity of Fort MacMurray, Alberta: a geothermal perspective. Master of Science thesis, Department of Earth and Atmospheric Sciences, University of Alberta, Canada" is not available online.
# 7
Lu, Biao • Förste, Christoph • Barthelmes, Franz • Petrovic, Svetozar • Flechtner, Frank • (et. al.)
Abstract: With the successful completion of ESA's PolarGAP campaign, terrestrial gravimetry data (gravity anomalies) are now available for both polar regions. Therefore, it is now possible to overcome the GOCE polar gap by using real gravimetry data instead of some regularization methods. But terrestrial gravimetry data needs to become filtered to remove the high-frequency gravity information beyond spher. harm. degree e.g. 240 to avoid disturbing spectral leakage in the satellite-only gravity field models. For the gravity anomalies from the Arctic, we use existing global gravity field models (e.g., EGM2008) for this filtering. But for the gravity anomalies from Antarctica, we use local gravity field models based on a point mass modeling method to remove the high-frequency gravity information. After that, the boundary-value condition from Molodensky's theory is used to build the observation equations for the gravity anomalies. Finally, variance component estimation is applied to combine the normal equations from the gravity anomalies, from the GOCE GGs (e.g., IGGT_R1), from GRACE (e.g., ITSG-Grace2014s) and for Kaula's rule of thumb (higher degree/order parts) to build a global gravity field model IGGT_R1C without disturbing impact of the GOCE polar gap. This new model has been developed by German Research Centre for Geosciences (GFZ), Technical University of Berlin (TUB), Wuhan University (WHU) and Huazhong University of Science and Technology (HUST). Parametersstatic model modelname IGGT_R1Cproduct_type gravity_fieldearth_gravity_constant 0.3986004415E+15radius 0.6378136460E+07max_degree 240norm fully_normalizedtide_system tide_freeerrors formal
# 8
Rudolf, Michael • Rosenau, Matthias • Ziegenhagen, Thomas • Ludwikowski, Volker • Schucht, Torsten • (et. al.)
Abstract: The presented datasets and scripts have been obtained for testing the performance of a trigger algorithm for use in combination with a ringshear tester ‘RST-01.pc’. Glass beads (fused quartz microbeads, 300-400 µm diameter) and thai rice are sheared at varying velocity, stiffness and normal load. The data is provided as preprocessed mat-files ('*.mat') to be opened with Matlab R2015a and later. Several scripts are provided to reproduce the figures found in (Rudolf et al., submitted). A detailed list of files together with the respective software needed to view and execute them is available in 'List_of_Files_Rudolf-et-al-2018.pdf' (also available in MS Excel Format). More information on the datasets and a small documentation of the scripts is given in 'Explanations_Rudolf-et-al-2018.pdf'. The complete data publication, including all descriptions, datasets, and evaluation scripts is available as 'Dataset_Rudolf-et-al-2018.zip'.
# 9
Wizemann, Hans-Dieter • Trebs, Ivonne • Wulfmeyer, Volker
Abstract: This dataset provides half-hourly surface energy balance measurements for a temperate grassland site in Luxembourg. The data were obtained during a field campaign in June and July 2015. The observations comprise multiple variables measurements by an Eddy-Covariance station, a net radiometer, soil moisture, temperature and soil heat flux probes and meteorological standard measurements. For details please see the reference article Renner et al. (2019, HESS) with the general setup described in Wizemann et al., 2015. The data are complemented by half-hourly model output of sensible and latent heat fluxes that are published as individual data publication (Renner et al., 2018).The data is provided as comma-separated-values (csv) format in a long table format. Columns represent Date, Time, variable, value, source. The column “variable” sets the name of the variable (following CEOP standards) with an information of the measurement depth for soil measurements. Column “source” describes the data source with an acronym(Observations “ObsEC”). The data contributes to the Joint Research Group "Catchments As Organized Systems" (CAOS) funded by the German Research Foundation. Methods: Eddy Covariance, Surface energy balance observations
# 10
Renner, Maik • Wizemann, Hans-Dieter • Brenner, Claire • Mallick, Kaniska • Trebs, Ivonne • (et. al.)
Abstract: This dataset provides half-hourly model output of sensible and latent heat fluxes simulated by three structurally different evapotranspiration schemes for a temperate grassland site in Luxembourg. All models use surface energy and meteorological observations as input. The observational data were collected during a field campaign in June and July 2015 and are distributed as complementary dataset by Wizemann et al., 2018. Two models are based on a parameterization of the sensible heat flux (OSEB, TSEB; see Brenner et al., 2017) and one model (STIC 1.2, Mallick et al., 2016) is a modification of the Penman-Monteith formulation using skin temperature as additional input variable. For details please see the reference article Renner et al., 2019, HESS. The data is provided as comma-separated-values (csv) format in a long table format. Columns represent Date, Time, variable, value, source. The column “variable” sets the name of the variable (following CEOP standards, https://www.eol.ucar.edu/field_projects/ceop). Column “source” describes the data source with an acronym representing the models (OSEB, TSEB, STIC). The data contributes to the Joint Research Group "Catchments As Organized Systems" (CAOS) funded by the German Research Foundation. Methods: land-surface modelling, evapotranspiration schemes
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