Distinct Results

Extraction, Identification and Usage of Signals in Seismic Ambient Noise:

• IRIS Webinar in Spanish on YouTube: El “Phase Weighted Stack” y el “Phase Cross-Correlation” para la extracción de señal en ruido sísmico .

• Ambient Seismic Noise Analysis / Monitoring (primary and secondary microseisms, GEOSCOPE global seismic network, seasonal variations of the noise, amplitude spectra, noise polarization, degree of elliptical polarization, climate impact, Northern/Southern Hemisphere, monitoring Antarctica ice changes, deep water SM in North Atlantic using tide modulations, SM from polarization analysis for Indian Ocean, SPSP Archipelago in equatorial Atlantic, ... ):
  Stutzmann et al., 2009 ; Schimmel et al., 2011b ; Beucler et al., 2015 ; Davy et al., 2015 ; de Queiroz et al., 2017 ; Carvalho et al., 2019 .

• Efficient Signal Extraction from Ambient Noise Cross-correlations (time-frequency domain phase weighted stack, phase cross-correlations, development, Green's functions, time and frequency domain normalization, GEOSCOPE, TAPAS array, body waves (P-phases), surface waves (R1, R2), wavelets, resampling, dispersion measurements, ...):
  Schimmel et al., 2011a ; Schimmel et al., 2017 ; Ventosa et al., 2017 ; Schimmel et al., 2018 .

• Monitoring Subtle Medium Changes (hydromechanical changes, precursors to volcanic erruption, El Hierro, small earthquake swarm, Reykjanes geothermal reservoir, phase cross-correlations and auto-correlations, ...):
  D'Hour et al., 2016 ; Sanchez-Pastor et al., 2018 ; Sanchez-Pastor et al., 2019 .

• Generation Mechanisms, Observations and Modelling Seismic Noise (generation of secondary microseisms, Longuet-Higgins (1950) & Hasselmann (1963), numerical ocean wave model WAVEWATCH III + improvements (ice berg distribution, coastal reflections, parametrization, ..., see IOWAGA), GEOSCOPE, synthetic noise power spectra of seismic displacement, modelling noise spectra for several years, deep water sources, theoretical development, array analyses, noise amplitudes, ...):
  Mainly Rayleigh waves:
  Ardhuin et al., 2011 ; Stutzmann et al., 2012 ; Obrebski et al., 2012 ; Gualtieri et al., 2013 ; Sergeant et al., 2013 .
  Mainly body waves:
  Obrebski et al., 2013 ; Gualtieri et al., 2014 ; Farra et al., 2016 ; Meschede et al., 2017 ; Meschede et al., 2019 .

• Ambient Noise Tomography (Rayleigh-wave, Group-velocity Maps of the Borborema Province (NE Brazil) and SW Iberia, global scale group velocity maps and 3-D inversion, 3-D group velocity inversions for Colombia, Costa Rica, Portugal):
  Carreiro-Dias et al., 2015 ; Haned et al., 2016 ; Corela et al., 2017 ; Poveda et al., 2018 ; Nuñez et al., 2020 ; Silveira et al., 2022 ; Carvalho et al., 2022 .

• Necessary Condition in Seismic Interferometry (theoretical development, noise cross-term cancellation, how much averaging needed? length of correlation windows and number of stacks, monitoring noise non-stationarity, analytic approach):
  Medeiros et al., 2015 (suppl. material ).

• Statistical Redundancy of Instantaneous Phases (theoretical development, instantaneous phase coherence statistics, instantaneous phase randomness characterization, noise cross-correlations, monitoring/characterizing ambient noise wavefield):
  Gaudot et al., 2016 .

• Measuring Group Velocities (robustly measure group velocities, time-frequency domain phase-weighted stack combined with data resampling and decision strategies):
  Schimmel et al., 2017 .

• Measuring Rayleigh Wave Ellipticity and Inversion (robustly measure Rayleigh wave ellipticity from ambient noise and event data, use time-frequency dependent polarization, non-linear inversion, velocity depth profiles and 3-D velocity maps, Greenland & Antartica, ...):
  Berbellini et al., 2019 ; Jones et al., 2021 .

• Ambient Noise and Event Coda Autocorrelations (zero-offset reflection response, orbiting surface waves, mapping crustal discontinuities, ... ):
  Romero & Schimmel, 2018 ; Schimmel et al., 2018 ; Andres et al., 2019 ; Buffoni et al., 2019 ; Andres et al., 2020 ; Compaire et al., 2021 ; Kim et al., 2021 ; Knapmeyer-Endrun et al., 2021 ; Schimmel et al., 2021 . Castro-Artola et al., 2022 ;

  Signal Detection, Noise Attenuation, Filter Design, Theory and Applications:

• Semi-Automated Group Velocity Determination (time-scale domain, resampling strategy, analytic signals, phase coherence, robust group arrival detections/measurements ...):
  Schimmel et al., 2017 .

• Lateral Phase-Coherence Filter (time-frequency domain, inverse S-transform, analytic signals, phase coherence, spatial averaging, array analysis, ...):
  Schimmel and Gallart, 2007 .

• S-Transform versus Morlet Wavelet Transform (new insights, comparisons and relations, ...):
  Ventosa et al., 2008 .

• Inverse S-Transform (motivation, new strategy, comparison, examples, numerical realization, ...):
  Schimmel and Gallart, 2005 ; Schimmel and Gallart, 2007 ; Simon et al., 2007 .

• Window Length for Local Slant Stack Transform (Adative optimum slowness resolution, derivation, examples, ...):
  Ventosa et al., 2012 , pdf .

• Time-Time Transform (rewriting the TT-transform in a new and more direct way, giving an interpretation of its diagonal elements):
  Simon et al. (2008) .

• Time-Frequency Domain Degree of Polarization Filter (time-frequency domain, spectral matrix, time,frequency and distance-slowness dependent averaging of degree of polarization, ...):
  Schimmel and Gallart, 2004 .

• Time-Domain Degree of Polarization Filter (time domain, complex trace analysis, instantaneous polarization, comparison to eigen approaches, covariance matrix, trade-off window length and power, local slowness-dependent averaging of seismic polarization attributes, ...)
  Schimmel and Gallart, 2003 .

• Sparsity-Promoting Polarization Approach in the Time-Frequency Domain (rearranged eigenvalue decomposition approach, improving resolution, adaptive filtering, sparsity promoting regularization):
  Mohammadigheymasi et al., 2022.

• Phase Cross-Correlations (PCC) (design of new amplitude-unbiased correlation, comparison to other methods, upper mantle discontinuities in Brazil (220km, 410km, 510km, 660km), transition zone, examples, ...):
  Schimmel, 1999 , summary with selected examples (HTML)

• Phase Weighted Stacking (PWS) (analytic signals, phase coherence, amplitude-unbiased coherence measure, non-linear stacking, vespagram, upper mantle discontinuities (410km, 660km), transition zone, examples, ... ):
  Schimmel and Paulssen, 1997 .
  Examples: Note that there are very nice observations/applications published by many other researchers.

  Monitoring Mines:

• Mine Tailings Dam Collapse at Mariana (SE Brazil, 05/11/2015) (small magnitude earthquake sequence, spatio-temporal relation of earthquakes and dam failure, seismic signals from mudflow,...):
  Agurto-Detzel et al., 2016 .

• Radar interferometry using Sentinel-1 C-band data (monitoring of surface variability in an active mine, Rio Tinto, South Spain,...):
  Escayo et al., 2022 .

• GEO3BCN-CSIC News on AGEMERA (Agile Exploration and Geo-modelling for European Critical Raw Materials) proyect (There exist a lot of outreach in the different media. The following links take you to notes/press-releases by the GEO3BCN-CSIC.):
  2022/11/14 (Español); 2022/11/14 (English);

  Seismic Tomography:

• Regional Body Wave Tomography (P-waves, S-waves, Brazil, robustness and resolution analyses, tectonics, upper mantle, ...):
  Schimmel et al., 2003 , seismic velocity anomaly model for SE Brazil, summary with selected examples (HTML), Rocha et al., 2011 , Simoes Neto et al., 2019 ,
  P-wave and S-wave velocity model published in Schimmel et al. (2003) : models (tar & bzip2 file) See end of this webpage for further information.

• Correlation Between Intraplate Seismicity and Tomography in SE and central Brazil (P-waves, Brazil, no correlation of seismic areas with main geological provinces, higher seismic activity in areas with low P-wave velocities at 150-250 km depth, intraplate force concentration in upper crust, high seismicity in regions of thinner lithosphere, ...):
  Assumpção et al., 2004 , Rocha et al., 2016 .

• Regional and Global Ambient noise tomography (Rayleigh-wave, group-velocity maps of the Borborema Province, NE Brazil; global scale group velocity maps and 3-D inversion; regional tomography, SW Iberia integrating seafloor- and land-based data for group velocity maps and 3-D inversions; regional tomography, group velocities and 3-D inversions for Colombian Andes, group velocities and 3-D inversions for Costa Rica, Portugal):
  Carreiro-Dias et al., 2015 ; Haned et al., 2016 ; Corela et al., 2017 ; Poveda et al., 2018 ; Nuñez et al., 2020 ; Silveira et al., 2022 ; Carvalho et al., 2022 .

• Regional 3-D Velocity Models from Rayleigh Wave Ellipticity Inversions (Mapping uppermost crustal structure underneath Greenland Ice Sheet, sublacial structure interaction controls dynamics of ice sheet.):
  Jones et al., 2021 .

  Mapping Discontinuities inside Earth:

• Basin Discontinuities Through Ambient Noise Auto/Cross-correlations (Ebro Basin, Spain; Potiguar Basin, Brazil):
  Romero and Schimmel, 2018 ; Dantas et al., 2018 .

• Basin Discontinuities Through Reverse Time Migration (Solimoes Basin, Amazon, Brazil; different image conditions, phase cross-correlation):
  Costa et al., 2018 .

• Basin Discontinuities/Structure through ambient noise studies: autocorrelations, horizontal to vertical spectra ratio, ambient noise Rayleigh wave tomography and band-pass filtered ambient noise amplitude mapping (Cerdanya Basin, Eastern Pyrenees, multi-method approach, high-density seismic network ):
  Diaz et al., 2022 .

• Moho Discontinuity Through Receiver Functions and Ambient Noise Cross/Auto-Correlations, Rayleigh Wave Dispersion Analyses (Isla Grande of Tierra del Fuego, Argentina. 550 km long MASE profile along center Mexico. Central Iberian Massif using ambient noise autocorrelations and Global-Phase Seismic Interferometry):
  Buffoni et al., 2018 ; Buffoni et al., 2019 ; Andres et al., 2019 ; Andres et al., 2020 ; Castro-Artola et al., 2022 .

• Upper Mantle Discontinuities (Detection and identification of coda waves which have been converted and/or reflected at upper mantle discontinuities):
  Schimmel and Paulssen,1997 ; Schimmel, 1999 ; Schimmel and Gallart, 2007 .

• 410-km and 660-km Discontinuities Beneath Spain and Morocco (Detection and identification of coda waves which have been converted and/or reflected at upper mantle discontinuities, Eurasian-African Plate boundary at south Spain and north Morocco, cross-correlations, TopoIberia, Alboran slab, constraints on temperature and composition, depth profiles, ...):
  Bonatto et al., 2013 (supplement) ; Bonatto et al., 2015 ( supplement).

• D" Discontinuities (Detection and identification of ScS (sScS and ScS2) precursors, focussing analysis to explain waveforms, modelling waveform variability and amplitudes, synthetic seismograms, Kirchhoff-Helmholtz theory.)
  Schimmel and Paulssen, 1996

  Environmental Seismology:

• Urban Seismology (City educational seismic networks. Connecting earth sciences and society. Characterization of seismic sources in urban environments(Barcelona, Brasila)):
  Diaz et al., 2020 ; Maciel et al., 2021 .

• GEO3BCN-CSIC News Distributed acoustic sensing (DAS) experiment in Barcelona. The following link takes you to the news:
  2021/05/06 (Spanish) ; 2021/05/06 (English)

  Planetary Seismology / Seismology on Mars:

• Seminar (Spanish) on YouTube, organized by the "Residencia d'investigadors, ciclo: SOS! Aqui la Tierra": Sismología en Marte: la Misión Insight .

• Pre-Deployment Analyses (Blind test for Martian seismicity. Analysis of global-scale Martian pressure and wind variations, corresponding contributions to the Martian hum, and detectability. Low-frequency ambient noise autocorrelations: Waveforms and normal modes.):
  Schimmel, Stutzmann, Ventosa, 2018 ; Nishikawa, Lognonné, Kawamura, et al., 2019 ; van Driel, Ceylan, Clinton, et al., 2019.

• First Seismic Analyses of Mars using InSight Data (Constraints of seismic structure on Mars from Marsquakes, dust devils, and noise. Scattering and attenuation. Characterisation of seismic noise, e.g., polarization as function of time and frequency. Seismic activity of Mars, Marsquake catalogue, data validation. Seismic receiver functions, ambient wavefield autocorrelations (seismic interferometry), H/V spectral ratios, surface wave evidence and structure, S-to-P- and P-to-S-wave conversions, distant events, crustal thickness, anisotropy, discontinuities, core radius, core reflections, ...):
  Giardini, Lognonné, Banerdt, et al., 2020 (see also Supplementary Material) ; Lognonne, Banerdt, Pike, et al., 2020 (see also Supplementary Material) ; Drilleau, Beucler, Lognonné, et al., 2020 ; Scholz, Widmer-Schnidrig, Davis, et al., 2020 ; Ceylan, Giardini, Boese, et al., 2021 ; Compaire, Margerin, Garcia, et al., 2021 ; Dahmen, Zehnhäusern, Clinton, et al., 2021 ; Kim, Davis, Lekic, et al., 2021 ; Knapmeyer-Endrun, Panning, Bissig, et al., 2021 (see also Supplementary Material) ; Schimmel, Stutzmann, Lognonné, et al., 2021 ; Stähler, Kahn, Banerdt, et al. 2021 (see also Supplementary Material) ; Stutzmann, Schimmel, Lognonné, et al., 2021 ; Carrasco, Knapmeyer-Endrun, Margerin, et al., 2022 ; Horleston, Clinton, Ceylan, et al., 2022 ; Kim, Banerdt, Ceylan, et al., 2022 ; Li, Beghein, Wookey, et al., 2022 ; Li, Beghein, Davis, et al., 2022 ;

• GEO3BCN-CSIC News (There exist a lot of outreach in the different media. The following links take you to notes/press-releases by the GEO3BCN-CSIC):
  2019/01/08 ; 2019/04/26 ; 2020/02/26 ; 2021/07/23 (English); 2021/07/23 (Español); 2022/10/27 (English); 2022/10/27 (Español); 2023/04/26 (Español); 2023/04/26 (English);

  Climate Reconstructions from Geological Measurements:

• Rainfall Reconstruction Through Annually Laminated Lake Sediments (Rainfall reconstruction, Iberian Peninsula, Calcite laminated sediment, North Atlantic Oscillation periodograms, climate variability,...):
  Romero-Viana et al., 2011.

  Bio-Medical Rhythm Detection, Theory and Applications:

• Premature Neonates (analysis of circadian and ultradian rhythmicities, premature babies, incubator, insulated skin temperature, environmental influence, folding algorithm, phasor walk out method, periodograms, ...):
  Schimmel et al., 2002 .

• Activity of Cave Crickets (Strinatia brevipennis) (analysis of rhythmicities through different methods, new phase weighted folding algorithm, evidence for circadian rhythmicities, isolation of environmental influence, controlled variation of environmental influences, ...):
  Hoenen, Schimmel, Marques, 2001 .

• Bio-Medical Rhythm Detection (non-sinoidal rhythms, new folding algorithm, Lomb-Scargle periodograms, benefits and limitations, unequally spaced data, ...):
  Schimmel, 2001a ; Schimmel, 2001b .