Principal component analysis vs. self-organizing maps combined with hierarchical clustering for pattern recognition in volcano seismic spectra

Abstract Variations in the spectral content of volcano seismicity related to changes in volcanic activity are commonly identified manually in spectrograms. However, long time series of monitoring data at volcano observatories require tools to facilitate automated and rapid processing. Techniques such as self-organizing maps (SOM) and principal component analysis (PCA) can help to quickly and automatically identify important patterns related to impending eruptions. For the first time, we evaluate the performance of SOM and PCA on synthetic volcano seismic spectra constructed from observations during two well-studied eruptions at Klauea Volcano, Hawai'i, that include features observed in many volcanic settings. In particular, our objective is to test which of the techniques can best retrieve a set of three spectral patterns that we used to compose a synthetic spectrogram. We find that, without a priori knowledge of the given set of patterns, neither SOM nor PCA can directly recover the spectra. We thus test hierarchical clustering, a commonly used method, to investigate whether clustering in the space of the principal components and on the SOM, respectively, can retrieve the known patterns. Our clustering method applied to the SOM fails to detect the correct number and shape of the known input spectra. In contrast, clustering of the data reconstructed by the first three PCA modes reproduces these patterns and their occurrence in time more consistently. This result suggests that PCA in combination with hierarchical clustering is a powerful practical tool for automated identification of characteristic patterns in volcano seismic spectra. Our results indicate that, in contrast to PCA, common clustering algorithms may not be ideal to group patterns on the SOM and that it is crucial to evaluate the performance of these tools on a control dataset prior to their application to real data.

[1]  B. Chouet,et al.  A multi-decadal view of seismic methods for detecting precursors of magma movement and eruption , 2013 .

[2]  Christian D. Klose,et al.  Self-organizing maps for geoscientific data analysis: geological interpretation of multidimensional geophysical data , 2006 .

[3]  T. Kohonen,et al.  Bibliography of Self-Organizing Map SOM) Papers: 1998-2001 Addendum , 2003 .

[4]  Bruce S. Hart,et al.  A visual data-mining methodology for seismic facies analysis: Part 1 — Testing and comparison with other unsupervised clustering methods , 2009 .

[5]  Germán Castellanos-Domínguez,et al.  A Comparison between Time-Frequency and Cepstral Feature Representations for the Classification of Seismic-Volcanic Signals , 2014, CIARP.

[6]  Cheng‐Horng Lin,et al.  Nonlinear Time Series Analysis of Volcanic Tremor Events Recorded at Sangay Volcano, Ecuador , 2004 .

[7]  S. Maryanto,et al.  Constraints on the source mechanism of harmonic tremors based on seismological, ground deformation, and visual observations at Sakurajima volcano, Japan , 2008 .

[8]  Roberto Carniel,et al.  Detecting dynamical regimes by Self-Organizing Map (SOM) analysis: an example from the March 2006 phreatic eruption at Raoul Island, New Zealand Kermadec Arc , 2013 .

[9]  C. Godano,et al.  Very-Long-Period Volcanic Tremor at Stromboli, Italy , 2005 .

[10]  William W. Hsieh,et al.  Machine Learning Methods in the Environmental Sciences: Neural Networks and Kernels , 2009 .

[11]  Inga Moeck,et al.  Pattern recognition and lithological interpretation of collocated seismic and magnetotelluric models using self-organizing maps , 2012 .

[12]  M. Fehler Observations of volcanic tremor at Mount St. Helens Volcano , 1983 .

[13]  Nasser M. Nasrabadi,et al.  Pattern Recognition and Machine Learning , 2006, Technometrics.

[14]  J. Lees,et al.  Degassing explosions at Karymsky Volcano, Kamchatka , 1998 .

[15]  E. Dunham,et al.  Frictional-faulting model for harmonic tremor before Redoubt Volcano eruptions , 2013 .

[16]  F. Murtagh,et al.  The Kohonen self-organizing map method: An assessment , 1995 .

[17]  Roberto Carniel,et al.  Analysis of phreatic events at Ruapehu volcano, New Zealand using a new SOM approach , 2013 .

[18]  J. Biggs,et al.  Monitoring Volcanoes , 2012, Science.

[19]  Maria Marinaro,et al.  Unsupervised Neural Analysis of Very-Long-Period Events at Stromboli Volcano Using the Self-Organizing Maps , 2008 .

[20]  Teuvo Kohonen,et al.  The self-organizing map , 1990 .

[21]  David Borland,et al.  Rainbow Color Map (Still) Considered Harmful , 2007 .

[22]  Tommy W. S. Chow,et al.  Clustering of the self-organizing map using a clustering validity index based on inter-cluster and intra-cluster density , 2004, Pattern Recognit..

[23]  Surono,et al.  Maximal Lyapunov exponent variations of volcanic tremor recorded during explosive and effusive activity at Mt Semeru volcano, Indonesia , 2013 .

[24]  Esa Alhoniemi,et al.  Self-organizing map in Matlab: the SOM Toolbox , 1999 .

[25]  Frank Scherbaum,et al.  Unsupervised feature selection and general pattern discovery using Self-Organizing Maps for gaining insights into the nature of seismic wavefields , 2009, Comput. Geosci..

[26]  Richard B. Alley,et al.  Relative Performance of Self-Organizing Maps and Principal Component Analysis in Pattern Extraction from Synthetic Climatological Data , 2005 .

[27]  Renato Campanini,et al.  Synopsis of supervised and unsupervised pattern classification techniques applied to volcanic tremor data at Mt Etna, Italy , 2009 .

[28]  M. Hellweg Physical models for the source of Lascar's harmonic tremor , 2000 .

[29]  Infrasonic tremor wavefield of the Pu`u `Ō`ō crater complex and lava tube system, Hawaii, in April 2007 , 2010 .

[30]  Jonathan M. Lees,et al.  Source constraints of Tungurahua volcano explosion events , 2006 .

[31]  M. Ripepe,et al.  Gas bubble dynamics model for shallow volcanic tremor , 1999 .

[32]  Daniel E. McNamara,et al.  Ambient Noise Levels in the Continental United States , 2004 .

[33]  H. Langer,et al.  Long-term observation of volcanic tremor on Stromboli volcano (Italy): A synopsis , 1996 .

[34]  Michael Ghil,et al.  ADVANCED SPECTRAL METHODS FOR CLIMATIC TIME SERIES , 2002 .

[35]  Michael B. Richman,et al.  On the Application of Cluster Analysis to Growing Season Precipitation Data in North America East of the Rockies , 1995 .

[36]  T. Nishimura,et al.  Volcanic tremor during eruptions: Temporal characteristics, scaling and constraints on conduit size and processes , 2008 .

[37]  H. Langer,et al.  Statistical analyses and characteristics of volcanic tremor on Stromboli Volcano (Italy) , 1998, Bulletin of Volcanology.

[38]  T. Kohonen Self-organized formation of topographically correct feature maps , 1982 .

[39]  D. Bercovici,et al.  Seismic tremors and magma wagging during explosive volcanism , 2010, Nature.

[40]  H. Langer,et al.  Detecting imminent eruptive activity at Mt Etna, Italy, in 2007-2008 through pattern classification of volcanic tremor data , 2011 .

[41]  G. Thompson,et al.  The seismicity of the 2009 Redoubt eruption , 2013 .

[42]  R. Hoblitt,et al.  CYCLIC ERUPTIVE BEHAVIOR OF SILICIC VOLCANOES , 1999 .

[43]  Ralph A. Stephen,et al.  Mid‐ocean microseisms , 2005 .

[44]  R. Scarpa,et al.  Evidence of VLP volcanic tremor in the band [0.2–0.5] Hz at Stromboli volcano, Italy , 2005 .

[45]  Teuvo Kohonen,et al.  Self-organized formation of topologically correct feature maps , 2004, Biological Cybernetics.

[46]  Samuel Kaski,et al.  Bibliography of Self-Organizing Map (SOM) Papers: 1981-1997 , 1998 .

[47]  R. Craster,et al.  Instability in flow through elastic conduits and volcanic tremor , 2005, Journal of Fluid Mechanics.

[48]  Vladimir Cherkassky,et al.  Learning from Data: Concepts, Theory, and Methods , 1998 .

[49]  K. Olsen,et al.  Models of tremor and low-frequency earthquake swarms on Montserrat , 2000 .

[50]  J. Lees,et al.  Switching between seismic and seismo‐acoustic harmonic tremor simulated in the laboratory: Insights into the role of open degassing channels and magma viscosity , 2013 .

[51]  Javier F. Pacheco,et al.  Complex behavior and source model of the tremor at Arenal volcano, Costa Rica , 2006 .

[52]  Donald W. Bouldin,et al.  A Cluster Separation Measure , 1979, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[53]  R. Leet Saturated and subcooled hydrothermal boiling in groundwater flow channels as a source of harmonic tremor , 1988 .

[54]  A. Jellinek,et al.  Volcanic tremor and frequency gliding during dike intrusions at Kı̄lauea—A tale of three eruptions , 2015 .

[55]  Jonathan M. Lees,et al.  Vent discrimination at Stromboli Volcano, Italy , 2004 .

[56]  R. Carniel,et al.  Spectral analysis of volcanic tremor associated with the 1993 paroxysmal events at Stromboli , 1996, Geological Society, London, Special Publications.

[57]  Christopher N. K. Mooers,et al.  Performance evaluation of the self‐organizing map for feature extraction , 2006 .

[58]  Max Chacón,et al.  Classification of seismic signals at Villarrica volcano (Chile) using neural networks and genetic algorithms , 2009 .

[59]  Remko Scharroo,et al.  Generic Mapping Tools: Improved Version Released , 2013 .

[60]  M. Chacón,et al.  Pattern recognition applied to seismic signals of the Llaima volcano (Chile): An analysis of the events' features , 2014 .

[61]  P. Nehlig,et al.  Tephrochronology of the Mont-Dore volcanic Massif (Massif Central, France): new 40Ar/39Ar constraints on the Late Pliocene and Early Pleistocene activity , 2014, Bulletin of Volcanology.

[62]  V. Radic,et al.  Evaluation of IPCC Models' Performance in Simulating Late-Twentieth-Century Climatologies and Weather Patterns over North America , 2011 .

[63]  S. Malone,et al.  Decomposition, location, and persistence of seismic signals recovered from continuous tremor at Erta 'Ale, Ethiopia , 2012 .

[64]  Mauricio Orozco-Alzate,et al.  The Automated Identification of Volcanic Earthquakes: Concepts, Applications and Challenges , 2012 .

[65]  Roberto Carniel Neural networks and dynamical system techniques for volcanic tremor analysis , 1996 .

[66]  J. Neuberg Characteristics and causes of shallow seismicity in andesite volcanoes , 2000, Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences.

[67]  B. Chouet,et al.  Applications of nonlinear dynamics to the history of seismic tremor at Kilauea Volcano, Hawaii , 1988 .

[68]  Stephen R. McNutt,et al.  New constraints on source processes of volcanic tremor at Arenal Volcano, Costa Rica, using broadband , 1997 .

[69]  Guillermo Cortés,et al.  A Comparative Study of Dimensionality Reduction Algorithms Applied to Volcano-Seismic Signals , 2016, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing.

[70]  Keiiti Aki,et al.  Source mechanism of volcanic tremor: fluid-driven crack models and their application to the 1963 kilauea eruption , 1977 .

[71]  Bruce R. Julian,et al.  Volcanic tremor: Nonlinear excitation by fluid flow , 1994 .

[72]  Roberto Carniel,et al.  Characterization of volcanic regimes and identification of significant transitions using geophysical data: a review , 2014, Bulletin of Volcanology.

[73]  J. Neuberg,et al.  What makes a volcano tick—A first explanation of deep multiple seismic sources in ascending magma , 2012 .

[74]  Bernice E. Rogowitz,et al.  Data visualization: the end of the rainbow , 1998 .

[75]  Anil K. Jain Data clustering: 50 years beyond K-means , 2010, Pattern Recognit. Lett..

[76]  Horst Langer,et al.  Pattern recognition of volcanic tremor data on Mt. Etna (Italy) with KKAnalysis - A software program for unsupervised classification , 2011, Comput. Geosci..

[77]  H. Langer,et al.  Seismic monitoring at Stromboli volcano (Italy): a case study for data reduction and parameter extraction , 2003 .

[78]  M. Matos,et al.  Unsupervised seismic facies analysis using wavelet transform and self-organizing maps , 2007 .

[79]  Bernard A. Chouet,et al.  Dynamics of a fluid-driven crack in three dimensions by the finite difference method , 1986 .

[80]  J. Hesthammer,et al.  Diagnosis of the Upper Cretaceous palaeokarst and turbidite systems from the Iranian Persian Gulf using volume-based multiple seismic attribute analysis and pattern recognition , 2007, Petroleum Geoscience.

[81]  Vera Schlindwein,et al.  Nature, wavefield properties and source mechanism of volcanic tremor: a review , 2003 .

[82]  Giuseppe Nunnari,et al.  Multivariate time series clustering on geophysical data recorded at Mt. Etna from 1996 to 2003 , 2013 .

[83]  M. I. Seht,et al.  Detection and identification of seismic signals recorded at Krakatau volcano (Indonesia) using artificial neural networks , 2008 .