1,720,985 research outputs found
3D Gorgon Shear Wave Velocity Model
No full textThis is the final 3D shear wave velocity model derived from the 3D interpolation of several 2D shear wave velocity models produced as a part Chen & Saygin (2022)
January 2022 Arthur River M 4.8 Earthquake - Recorded by Perth DAS cable
No full textThese are the data files (SAC) of the Arthur River 24 January 2022, 21:24:47 (UTC) earthquake. Each SAC file contains coordinate information of the sensing point with duration minimum expected P wave arrival time - 20s (tp is uniform for all channels). The data was downsampled to 100 Hz. \nLineage: Data was produced via connecting CSIRO owned iDAS v2 DAS interrogator to the unused telecom cables located in the AARC building - Level 1, Kensington, WA
AuSeis: A seismic model for the Australian crust obtained from the inversion of teleseismic P-wave coda autocorrelation
No full textAuSeis makes use of the teleseismic waveforms recorded on the vertical components of 1200 permanent and temporary seismic stations across Australia. It includes the first-order estimates of the crustal Vp, Vs, Vp/Vs, density and Moho depth. It has been obtained by inverting the autocorrelations of teleseismic P-wave coda through a Markov Chain Monte Carlo approach. For further details, please refer to the paper referenced above (https://doi.org/10.1029/2018JB017055).\n\nThe results of the inversion are provided as ASCII files (.dat and .xyz files). The zip file containing the results includes the following:\n\n“Best_2000_Models” includes the best 2000 accepted 1-D models for each seismic station. The models give the thickness, depth, Vp, Vs and Vp/Vs of each crustal layer. For each station, the best 2000 accepted horizontal slowness value (s/km) are also given in the last column of each file. This parameter can be particularly useful to create synthetic seismograms associated with each of the models provided in the files.\n“1-D Models” includes the average of 1-D crustal properties (Vp, Vs, density, depth, Vp/Vs, and Moho) and their associated one sigma uncertainty for each seismic station. The mean and one sigma uncertainty for each of the crustal properties are calculated from the best 2000 accepted models.\n“AuSeis_Crustal_Model” includes an ASCII grid file (“AuSeis_Crustal_Model.xyz”). The file includes grids of seismic crustal properties (Vp, Vs, Vp/Vs, density) and their related one sigma uncertainties. The grid interval in the x and y directions is 0.5 degree, and the depth interval is 5 km. More information about the columns are provided in the file at the top of the file.\n“AuSeis_Moho” includes a file (“AuSeis_Moho_From_1D_Models.dat”) containing Moho depths and their one sigma uncertainty.\n“Stations_Used.dat” is a list of all stations used in this study. The file is organised with the following format: name of the seismic station, name of the seismic network, longitude (degree), and latitude (degree).\nLineage: It has been obtained by inverting the autocorrelations of the teleseismic P-wave coda through a Markov Chain Monte Carlo approach. For further details, please refer to the paper referenced above (https://doi.org/10.1029/2018JB017055)
Dataset and 3D Vs Model for "Crustal velocity images of north-western Türkiye along the North Anatolian Fault Zone from transdimensional Bayesian ambient seismic noise tomography"
No full text<b>External Organisations</b><br/>Istanbul Technical University; Zhejiang University; University of Leeds<b>Associated Persons</b><br/>Buse Turunctur (Creator); Tuna Eken (Creator); Yunfeng Chen (Creator); Tuncay Taymaz (Creator); Gregory A. Houseman (Creator)Final 3D Vs model and dispersion data for the paper entitled "Crustal velocity images of north-western Türkiye along the North Anatolian Fault Zone from transdimensional Bayesian ambient seismic noise tomography". In the vel_files folder, there are 10 files for each depth for 1-15 km. The format of each velocity file is as follows: Column Value 1 Lattitude (°) 2 Longitude (°) 3 Vs (km/s) The format of the dispersion data is as follows (See Computer Programs in Seismology Tutorials - do_mft for more information on the format): Column Value 1 Type of file, MFT96 2 Wave type: R for Rayleigh 3 Dispersion type: U for group velocity 4 Mode: 0 represents the fundamental mode 5 Filter period, T, in seconds 6 Dispersion value, either group or phase 7 Error in dispersion. This is just a place holder since there is no way to estimate an error from a single trace. The group velocity error is determined from the ratio of the filter period to travel time 8 Distance in km 9 Azimuth from the source to the receiver 10 Spectral amplitude. 11 Epicenter latitude 12 Epicenter longitude 13 Station latitude 14 Station longitude 15 control flag 16 control flag 17 Instantaneous period if this is preferred. This differs from the ilter period because the signal spectram is not flat. 18 Comment: keyword 19 Station 20 Component 21 Year 22 Day of year 23 Hour 24 Minute - these identify the event origin tim
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Empirical Green’s Function Retrieval using Cross-correlation of Ambient Noise Correlations (C2)
No full textEmpirical Green's function (EGF) retrieval commonly relies on cross-correlating the long-term ambient seismic wavefield that is simultaneously recorded at multiple stations. Recent studies have demonstrated observationally that cross-correlating the coda of ambient noise cross-correlation functions (C3) enables reconstruction of the EGFs, regardless of the operating time of the stations. In this study, we develop a new technique to perform correlation of cross-correlation functions (C2), thus permitting the reconstruction of asynchronous EGFs. Our approach exploits the deterministic wavefield rather than the diffusive codas that may be affected by incoherent energy under non-ideal (e.g., sparse, noisy and short-duration) network configurations. We demonstrate the robustness of C2 by retrieving asynchronous EGFs between 1) nearby stations and 2) distant temporary arrays from southern Australia. The accuracy of the EGFs from C2 are examined by analyzing seismic tomography of Rayleigh wave group velocities and benchmarking them with the results from conventional ambient noise imaging. The additional ray paths from asynchronous C2 functions provide better illumination of small-scale crustal structures beneath the regional network. In the larger-scale example, involving two asynchronous arrays, the implementation of the C2 method offers new constraints to the sparsely sampled region of the southern Australian offshore. The resulting velocity model agrees well with the independent structural constraints from individual seismic array studies and sedimentary thickness measurements. This study demonstrates that C2 is a promising tool for integrating transportable arrays deployed at different times and can greatly benefit the effort of improving seismic data coverage and resolution in crustal imaging
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