API src

Found 8 results.

Other language confidence: 0.8674272502396008

Seasonality of damage-inducing torrential events in Austria (1962-2017)

Frequency of damage-inducing torrential events in Austria (1962-2017)

Frequency, magnitude and seasonality of damage-inducing torrential events in Austria (1962-2017)

Information on frequency, magnitude and seasonality of damage-inducing torrential flooding events from steep, alpine headwater catchments (torrents) in Austria, for the period from 1962 to 2017. The datasets are based on information from the Austrian torrential event catalogue. The frequency data set is complemented with information on the number of functional torrential structures (technical mitigation measures), the number of exposed buildings as well as a multitude of climate indices related to precipitation, snow melt and the sum of precipitation plus snowmelt. Annual aggregates are derived by using area-weighted means across all catchments.

Magnitude of damage-inducing torrential events in Austria (1962-2017)

Earthquake catalog of induced seismicity recorded during and after stimulation of Enhanced Geothermal System in Helsinki, Finland

The dataset is supplementary material to the Solid Earth research article of Leonhardt et al. (2021). The dataset is a high-resolution catalog of seismicity framing the stimulation campaign of a 6.1 km deep Enhanced Geothermal System (EGS) in Helsinki suburban area, Finland. Within the St1 Deep Heat project, a total of 18,160 m3 of fresh water was injected into crystalline rocks during 49 days in summer 2018. The seismicity was monitored by a 12-level seismometer array at >2km depth and a seismic network of near-surface borehole sensors surrounding the EGS site. We expanded and refined the original catalog of Kwiatek et al. (2019) including detected seismic events and earthquakes that occurred two month after the end of injection and determining new locations and relocations on the basis of a new velocity model derived from a post-stimulation vertical seismic profiling campaign. A detailed description of the catalog reprocessing as well as a description of basic statistical and spatio-temporal properties of the catalog can be find in the data description file. Definition of columns in the data table (also in the header of the data): event ID, event class, datenumber [integer part = day since year 0], year, month, day, hour, minute, seconds, local magnitude MLHEL, moment magnitude MW, absolute location in local cartesian coordinates [easting (m), northing (m), altitude (m)], relocated location in local cartesian coordinates [easting (m), northing (m), altitude (m)], fault plane solutions of estimated focal mechnisms [strike (°), dip (°), rake(°)] and root mean square fault plane uncertainty of estimated focal mechanisms.

Acoustic emission source parameters of laboratory triaxial stick-slip experiments on two Westerly granite samples

These data are supplementary to the GJI research article of Blanke et al. 2020, in which static stress drop estimates of laboratory acoustic emission (AE) waveform records were analyzed. Stick-slip experiments were conducted on two triaxial loaded Westerly Granite samples of different roughness: 1) a smooth saw-cut fault (sample S12) and 2) a rough fault (sample W5). Both experiments resulted in six stick-slip failures of which five were analyzed for each fault. A variant of the spectral ratio technique was applied to find the best fitting source parameters. Laboratory Experiments: Acoustic emission waveform data of two triaxial stick-slip experiments was recorded at room temperature on cylindrical oven-dried Westerly Granite samples of 105-107 mm height and 40-50 mm diameter. The experiments were conducted on a smooth saw-cut (sample S12) and a rough fault (sample W5). Both experiments were performed in a servo-controlled MTS loading frame equipped with a pressure vessel. The acoustic emission activity was monitored by 16 piezoceramic transducers with a resonance frequency of about 2 MHz. A transient recording system (DAX-Box, Prökel, Germany) recorded full waveform data in triggered mode at a sampling frequency of 10 MHz and an amplitude resolution of 16 bits. The rough fault W5 was first prepared with Teflon-filled saw-cut notches at 30° inclination to the vertical axis and then fractured at 75 MPa. Then, each sample, S12 and W5, was subjected to constant confining pressure of 133 MPa and 150 MPa and then loaded in axial compression using a strain rate of 3*10-4 mm/s and 3*10-6 mm/s, respectively. Data description: The tables 2020-008_Blanke-et-al_S1_S12.txt and 2020-008_Blanke-et-al_S2_W5.txt contain AE locations and occurrence, and source parameter estimates of the smooth fault S12 and the rough fault W5, respectively. Both column headers show coordinates of AE locations (X, Y, Z [mm]), temporal occurrence (t [sec]), seismic moment (M0 [Nm]), corner frequency (f0 [Hz]), source radius (r [mm]), static stress drop (stress drop [MPa]), and moment magnitude (MW). M0 and f0 were estimated from the amplitude spectra, using the spectral ratio technique. The source radii were calculated for S-waves using the dynamic circular source model of Madariaga (1976). Static stress drops were estimated following Eshelby (1957). Both tables are used and displayed in Blanke et al. (2020).

Source parameters of relocated earthquakes recorded during hydraulic stimulation within St1 Deep Heat project in Espoo, Finland

The dataset is supplementary material to Kwiatek et al. (2019, Science Advances).The dataset is a refined seismic catalog acquired during the hydraulic stimulation of the future geothermal sites located in Espoo, Finland. There, the injection well, OTN-3, was drilled down to 6.1 km-depth into Precambrian crystalline rocks. Well OTN-3 was deviated 45° from vertical and an open hole section at the bottom was divided into several injection intervals. A total of 18,159 m3 of fresh water was pumped into crystal-line rocks during 49 days in June- and July, 2018. The stimulation was monitored in near-real time using (1) a 12-level seismometer array at 2.20-2.65 km depth in an observation well located ~10 m from OTN3 and (2) a 12-station network installed in 0.3-1.15 km deep bore-holes surrounding the project site. On completion of stimulation it the catalog contained 8452 event detections overall, and 6152 confirmed earthquakes located in the vicinity of the project site (epicentral distance from the well head of OTN-3 <5 km). These were recorded in a time period lasting 59 days: 49 days of active stimulation campaign and the 10 days following completion.The initial industrial seismic catalog of 6150 earthquakes was manually reprocessed. The P- and S-wave arrivals of larger seismic events with M>0.5 were all manually verified, and, if necessary, refined. Earthquakes with sufficient number of phases and seemingly anomalous hypocenter depths (e.g. very shallow or very deep) were manually revised as well. The hypocenter locations were calculated using the Equivalent differential time method and optimized with an Adaptive Simulated Annealing algorithm. The updated catalog contained 4,580 earthquakes that occurred at hypocenter depths 4.5-7.0 km, in the vicinity of the stimulation section of OTN-3. To increase the precision of their locations, the selected 2155 earthquakes with at least 10 P-wave and 4 S-wave picks were relocated using the double-difference relocation technique. The relocation uncertainties were estimated using bootstrap resampling technique. The relocation reduced the relative precision of hypocenter determination to approx. 66 m and 27 m for 95% and 68% of relocated earthquakes. The final relocated catalog that constitutes the here published contained 1,977 earthquakes (91% of the originally selected events).

Palaeoseismische Untersuchungen in Mitteleuropa

Erforschung praehistorischer Erdbeben mit geologischen Methoden: Aufnahme von Profilen quer zu den geologisch aktiven Hauptverwerfungen der Niederrheinischen Bucht, Ermittlung der seismotektonischen Bewegungsraten und der Wiederkehrperioden staerkerer Erdbeben, Bestimmung der Magnituden und Abschaetzung des seismischen Risikos. Analoge Untersuchungen werden in anderen Teilen Mitteleuropas durchgefuehrt.

1