Intra-continental earthquake swarms in West-Bohemia and Vogtland: A review

article i nfo Earthquake swarmsand highCO2 flowof mantle origin are the characteristicfeatures of West Bohemia/Vogtland (Central Europe). At present, the highest concentration of earthquake activity and CO2 degassing occurs in the area of the Cheb Basin at the intersection of the Eger Rift and Regensburg-Leipzig-Rostock Zone with three Quaternary active volcanoes. We review about 140 studies on structure, tectonics, volcanism, seismicity, earth- quake source, triggering mechanisms, and gas-isotope geochemistry focused on the earthquake swarms from this area with the aim to build a complex image of the ongoing processes and find a possible link between activity of the mantle-derived fluids and the earthquake swarms. The so far unpublished data on the 2011 swarm and little known data on the 1824 swarm are presented, as well, showing that earthquake swarms ac- tivate a complex fault system and display long-term migration that differs from the occurrence of CO2 escapes. The activity of individual swarms is consistent with models involving high-pressure fluids; the isotopic signa- ture of the rising gas proves its origin at depths below the hypocenters. We show that the earthquake swarms and degassing of CO2 of magmatic origin represent common result of the geodynamic activity of the area. Nevertheless, current knowledge does not preclude processes other than fluid-induced failure in triggering swarm seismicity.

[1]  G. Grünthal,et al.  A combined study of macroseismic data and focal mechanisms applied to the West-Bohemian earthquake, Czechoslovakia , 1990 .

[2]  Tomáš Fischer,et al.  Intraplate seismicity in the western Bohemian Massif (central Europe): A possible correlation with a paleoplate junction , 2007 .

[3]  K. Bräuer,et al.  Evidence for a nitrogen flux directly derived from the European subcontinental mantle in the Western Eger Rift, Central Europe , 2004 .

[4]  T. Fischer,et al.  Source parameters of the swarm earthquakes in West Bohemia/Vogtland , 2013 .

[5]  V. Vavryčuk,et al.  High-resolution fault image from accurate locations and focal mechanisms of the 2008 swarm earthquakes in West Bohemia, Czech Republic , 2013 .

[6]  T. Fischer,et al.  Geological interpretation of gravity profiles through the Karlovy Vary granite massif (Czech Republic) , 2009 .

[7]  H. Konietzky,et al.  Hydrothermal alteration as a trigger mechanism for earthquake swarms: the Vogtland/NW Bohemia region as a case study , 2009 .

[8]  L. Vecsey,et al.  FAST TRACK PAPER: Upper mantle beneath the Eger Rift (Central Europe): plume or asthenosphere upwelling? , 2007 .

[9]  U. Enderle,et al.  The refraction seismic experiment GRANU95 in the Saxothuringian belt, southeastern Germany , 1998 .

[10]  J. Angelier.  Inversion of earthquake focal mechanisms to obtain the seismotectonic stress IV—a new method free of choice among nodal planes , 2002 .

[11]  M. Korn,et al.  Seismicity and seismotectonics of West Saxony, Germany — new insights from recent seismicity observed with the Saxonian seismic network , 2008 .

[12]  J. Šílený,et al.  Moment tensors of the January 1997 earthquake swarm in NW Bohemia (Czech Republic): double-couple vs. non-double-couple events , 2002 .

[13]  John W. Gephart,et al.  An improved method for determining the regional stress tensor using earthquake focal mechanism data: Application to the San Fernando Earthquake Sequence , 1984 .

[14]  P. Kolář.  FINITE SEISMIC SOURCE PARAMETERS INFERRED FROM STOPPING PHASES FOR SELECTED EVENTS OF WEST BOHEMIA 2000 SWARM , 2012 .

[15]  E. Rothert,et al.  Pore‐pressure diffusion: A possible triggering mechanism for the earthquake swarms 2000 in Vogtland/NW‐Bohemia, central Europe , 2003 .

[16]  P. Bankwitz,et al.  Structural characteristics of epicentral areas in Central Europe: study case Cheb Basin (Czech Republic) , 2003 .

[17]  J. Valenta,et al.  GROUNDWATER LEVEL VARIATIONS IN THE SEISMICALLY ACTIVE REGION OF WESTERN BOHEMIA IN THE YEARS 2005-2010 , 2011 .

[18]  W. Rabbel.  Seismic anisotropy at the continental deep drilling site (Germany) , 1994 .

[19]  H. Kämpf,et al.  Seismic evidence for asthenospheric updoming beneath the western Bohemian Massif, central Europe , 2006 .

[20]  J. Owen.  Isotopic Evidence , 2019, Hydromagmatic Processes and Platinum-Group Element Deposits in Layered Intrusions.

[21]  Tomáš Fischer,et al.  The Western Bohemia/Vogtland Region in the Light of the Webnet Network , 2000 .

[22]  Tomáš Fischer,et al.  Detection capability of seismic network based on noise analysis and magnitude of completeness , 2014, Journal of Seismology.

[23]  T. Fischer.  The August–December 2000 earthquake swarm in NW Bohemia: the first results based on automatic processing of seismograms , 2003 .

[24]  V. Vavryčuk,et al.  Accuracy of the master-event and double-difference locations: synthetic tests and application to seismicity in West Bohemia, Czech Republic , 2013, Journal of Seismology.

[25]  Michael I. Jordan,et al.  A mantle plume below the Eifel volcanic fields, Germany , 2001 .

[26]  M. Moreira,et al.  He, Ne and Ar composition of the European lithospheric mantle , 2005 .

[27]  T. Dahm,et al.  Mechanical intrusion models and their implications for the possibility of magma-driven swarms in NW Bohemia Region , 2008 .

[28]  Tomáš Fischer,et al.  Indications for a successively triggered rupture growth underlying the 2000 earthquake swarm in Vogtland/NW Bohemia , 2002 .

[29]  K. Bräuer,et al.  Monthly monitoring of gas and isotope compositions in the free gas phase at degassing locations close to the Nový Kostel focal zone in the western Eger Rift¸ Czech Republic , 2011 .

[30]  M. Wilson,et al.  Imaging a mantle plume beneath the French Massif Central , 1995 .

[31]  M. Zoback,et al.  Estimation of the complete stress tensor to 8 km depth in the KTB scientific drill holes: Implications for crustal strength , 1997 .

[32]  H. Maluski,et al.  Terrane boundaries in the Bohemian Massif: Result of large-scale Variscan shearing , 1990 .

[33]  F. Scherbaum,et al.  Monitoring the West Bohemian earthquake swarm in 2008/2009 by a temporary small-aperture seismic array , 2012, Journal of Seismology.

[34]  V. Vavryčuk,et al.  S-wave splitting from records of local micro-earthquakes in West Bohemia/Vogtland: An indicator of complex crustal anisotropy , 2008 .

[35]  S. Mueller,et al.  The European Cenozoic rift system , 1996 .

[36]  P. Tábořík,et al.  Imaging the Mariánské Lázně Fault (Czech Republic) by 3-D ground-penetrating radar and electric resistivity tomography , 2012, Studia Geophysica et Geodaetica.

[37]  T. Fischer.  Modelling of multiple events using empirical Green’s functions: method, application to swarm earthquakes and implications for their rupture propagation , 2005 .

[38]  S. Shapiro,et al.  Estimating the crust permeability from fluid-injection-induced seismic emission at the KTB site , 1997 .

[39]  J. Saul,et al.  Differences in the Crustal and Uppermost Mantle Structure of the Bohemian Massif from Teleseismic Receiver Functions , 2005 .

[40]  G. Leydecker,et al.  Erdbebenkatalog für Deutschland mit Randgebieten für die Jahre 800 bis 2008 , 2011 .

[41]  V. Vavryčuk.  Crustal anisotropy from local observations of shear-wave splitting in West Bohemia, Czech Republic , 1993, Bulletin of the Seismological Society of America.

[42]  K. Mogi.  Some Discussions on Aftershocks, Foreshocks and Earthquake Swarms : the Fracture of a Semi-infinite Body Caused by an Inner Stress Origin and Its Relation to the Earthquake Phenomena (Third Paper) , 1963 .

[43]  V. Vavryčuk.  Comment on the “Analysis of the State of Stress During the 1997 Earthquake Swarm in Western Bohemia” by A. Slancová and J. Horálek (Studia geoph. et geod. 44(2000), 272–291) , 2000 .

[44]  T. Dahm,et al.  FAST TRACK PAPER: The creation of an asymmetric hydraulic fracture as a result of driving stress gradients , 2009 .

[45]  Garry Rogers.  Fault plane solutions , 1980 .

[46]  J. Horalek,et al.  Analysis of State of Stress During The 1997 Earthquake Swarm In Western Bohemia , 2000 .

[47]  Shin-Chan Han,et al.  Source parameter inversion for recent great earthquakes from a decade‐long observation of global gravity fields , 2013 .

[48]  E. Brückl,et al.  Crustal structure due to collisional and escape tectonics in the Eastern Alps region based on profiles Alp01 and Alp02 from the ALP 2002 seismic experiment , 2007 .

[49]  G. Molchan.  Interevent Time Distribution in Seismicity: A Theoretical Approach , 2004, physics/0404111.

[50]  V. Čermák,et al.  Subsurface Temperature Changes Due to the Crustal Magmatic Activity – Numerical Simulation , 2000 .

[51]  A. Hemmann,et al.  Earthquake swarms in the Vogtland/Western Bohemia region: Spatial distribution and magnitude–frequency distribution as an indication of the genesis of swarms? , 2005 .

[52]  P. Hrubcová,et al.  The crust-mantle transition and the Moho beneath the Vogtland/West Bohemian region in the light of different seismic methods , 2009 .

[53]  V. Stejskal,et al.  Variations in discharge and temperature of mineral springs at the Františkovy Lázně spa, Czech Republic, during a nearby earthquake swarm in 1985/1986 , 2008 .

[54]  K. Bräuer,et al.  Combined Gas-geochemical and Receiver Function Studies of the Vogtland/NW Bohemia Intraplate Mantle Degassing Field, Central Europe , 2007 .

[55]  V. Vavryčuk.  Detection of high-frequency tensile vibrations of a fault during shear rupturing: observations from the 2008 West Bohemia swarm , 2011 .

[56]  J. Plomerová,et al.  Boundaries of mantle-lithosphere domains in the Bohemian Massif as extinct exhumation channels for high-pressure rocks , 2013 .

[57]  Andreas Barth,et al.  The World Stress Map database release 2008, 1:46 , 2008 .

[58]  Johnston,et al.  Dilational processes accompanying earthquakes in the long valley caldera , 2000, Science.

[59]  S. Stein.  Fault plane solutions , 1987 .

[60]  T. Dahm,et al.  Seismicity-based estimation of the driving fluid pressure in the case of swarm activity in Western Bohemia , 2012 .

[61]  K. Bräuer,et al.  An active subcontinental mantle volatile system in the western Eger rift, Central Europe: Gas flux, isotopic (He, C, and N) and compositional fingerprints , 1999 .

[62]  V. Vavryčuk.  Tensile earthquakes: Theory, modeling, and inversion , 2011 .

[63]  W. Geissler,et al.  Receiver function search for a baby plume in the mantle transition zone beneath the Bohemian Massif , 2011 .

[64]  T. Dahm,et al.  Comparison of Absolute and Relative Moment Tensor Solutions For The January 1997 West Bohemia Earthquake Swarm , 2000 .

[65]  P. Hrubcová,et al.  Moho depth determination from waveforms of microearthquakes in the West Bohemia/Vogtland swarm area , 2013 .

[66]  Jonathan M. Lees,et al.  Multiplet analysis at Coso geothermal , 1998, Bulletin of the Seismological Society of America.

[67]  J. Fiala,et al.  The lithology , geochemistry , and metamorphic gradation of the crystalline basement of the Cheb ( Eger ) Tertiary Basin , Saxothuringian Unit , 2004 .

[68]  T. Dahm,et al.  Velocity ratio variations in the source region of earthquake swarms in NW Bohemia obtained from arrival time double-differences , 2014 .

[69]  V. Vavryčuk.  Non-double-couple earthquakes of 1997 January in West Bohemia, Czech Republic: evidence of tensile faulting , 2002 .

[70]  J. Havíř.  Stress Analyses in the Epicentral Area of Nový Kostel (Western Bohemia) , 2000 .

[71]  Tomáš Fischer,et al.  Seismic regime of the west Bohemian earthquake swarm region: Preliminary results , 1996 .

[72]  K. Bräuer,et al.  Natural laboratory NW Bohemia: Comprehensive fluid studies between 1992 and 2005 used to trace geodynamic processes , 2008 .

[73]  J. Málek,et al.  One-Dimensional qP-Wave Velocity Model of the Upper Crust for the West Bohemia/Vogtland Earthquake Swarm Region , 2005 .

[74]  U. Koch,et al.  Slug Flow—A Possible Explanation for Hydrogeochemical Earthquake Precursors at Bad Brambach, Germany , 2000 .

[75]  E. Faber,et al.  Continuous gas monitoring in the West Bohemian earthquake area, Czech Republic: First results , 2009 .

[76]  U. Koch,et al.  Hydrogeological effects of the latest Vogtland-NW Bohemian swarmquake period (August to December 2000) , 2003 .

[77]  Three-dimensional seismic velocity model of the West Bohemia/Vogtland seismoactive region , 2013 .

[78]  Yosihiko Ogata,et al.  Detecting fluid signals in seismicity data through statistical earthquake modeling , 2005 .

[79]  A. Brauer,et al.  Discovery of the first Quaternary maar in the Bohemian Massif, Central Europe, based on combined geophysical and geological surveys , 2009 .

[80]  M. I. Seht,et al.  Earthquake swarms in continental rifts — A comparison of selected cases in America, Africa and Europe , 2008 .

[81]  Tomáš Fischer,et al.  Shear and tensile earthquakes caused by fluid injection , 2011 .

[82]  T. Dahm,et al.  Bidirectional and unidirectional fracture growth during hydrofracturing: Role of driving stress gradients , 2010 .

[83]  Thomas Plenefisch,et al.  Seismic structure and location of a CO2 source in the upper mantle of the western Eger (Ohře) Rift, central Europe , 2005 .

[84]  U. Koch,et al.  Seismohydrological effects related to the NW Bohemia earthquake swarms of 2000 and 2008: Similarities and distinctions , 2011 .

[85]  Václav Vavryčuk,et al.  Inversion for parameters of tensile earthquakes , 2001 .

[86]  V. Cílek,et al.  Evolution of hot-spring travertine accumulation in Karlovy Vary/Carlsbad (Czech Republic) and its significance for the evolution of Teplá valley and Ohře/Eger rift , 2007 .

[87]  J. Mrlina,et al.  Relation of surface movements in West Bohemia to earthquake swarms , 2008 .

[88]  M. Christie,et al.  Masking of earthquake triggering behavior by a high background rate and implications for epidemic‐type aftershock sequence inversions , 2011 .

[89]  P. Hrubcová,et al.  Lithospheric structure of the Bohemian Massif and adjacent Variscan belt in central Europe based on profile S01 from the SUDETES 2003 experiment , 2008 .

[90]  K. Bräuer,et al.  Isotopic evidence (3He/4He, of fluid‐triggered intraplate seismicity , 2003 .

[91]  Weak tidal correlation of NW-Bohemia/Vogtland earthquake swarms , 2006 .

[92]  S. Hainzl.  Seismicity patterns of earthquake swarms due to fluid intrusion and stress triggering , 2004 .

[93]  T. Fischer,et al.  Role of crustal fluids in triggering the West Bohemia/Vogtland earthquake swarms: Just what we know (a review) , 2008 .

[94]  K. Bräuer,et al.  Earthquake swarms in non‐volcanic regions: What fluids have to say , 2009 .

[95]  Jiří Zahradník,et al.  Toward Understanding Subtle Instrumentation Effects Associated with Weak Seismic Events in the Near Field , 2010 .

[96]  K. Bräuer,et al.  Seismically induced changes of the fluid signature detected by a multi‐isotope approach (He, CO2, CH4, N2) at the Wettinquelle, Bad Brambach (central Europe) , 2007 .

[97]  W. Seifert,et al.  Petrological and seismic studies of the lithosphere in the earthquake swarm region Vogtland/NW Bohemia, central Europe , 2007 .

[98]  T. Fischer.  Space-time distribution of earthquake swarms in the principal focal zone of the NW Bohemia/Vogtland seismoactive region: period 1985–2001 , 2003 .

[99]  Reinhard Dietrich,et al.  Determination of recent crustal deformations based on precise GPS measurements in the Vogtland earthquake area , 2003 .

[100]  V. Vavryčuk.  Principal earthquakes: Theory and observations from the 2008 West Bohemia swarm , 2011 .

[101]  T. Fischer,et al.  Post 2000-swarm microearthquake activity in the principal focal zone of West Bohemia/Vogtland: Space-time distribution and waveform similarity analysis , 2008 .

[102]  G. R. Keller,et al.  Crustal and uppermost mantle structure of the Bohemian Massif based on CELEBRATION 2000 data , 2005 .

[103]  Tomáš Fischer,et al.  Slip‐generated patterns of swarm microearthquakes from West Bohemia/Vogtland (central Europe): Evidence of their triggering mechanism? , 2005 .

[104]  Stefan Wiemer,et al.  Mapping active magma chambers by b values beneath the off‐Ito volcano, Japan , 1997 .

[105]  K. Bräuer,et al.  Evidence for ascending upper mantle‐derived melt beneath the Cheb basin, central Europe , 2005 .

[106]  Stillweg Bmienzorshung.  Results of deep reflection seismic profiling in the Oberpfalz (Bavaria) , 1987 .

[107]  T. Bohlen,et al.  Superdeep vertical seismic profiling at the KTB deep drill hole (Germany): Seismic close-up view of a major thrust zone down to 8.5 km depth , 2004 .

[108]  W. Rabbel,et al.  P-receiver functions of anisotropic continental crust: a hierarchic catalogue of crustal models and azimuthal waveform patterns , 2011 .

[109]  Carsten Rücker,et al.  Geoelectrical investigations in the Cheb Basin/W-Bohemia: An approach to evaluate the near-surface conductivity structure , 2010 .

[110]  T. Fischer,et al.  The 2008 West Bohemia earthquake swarm in the light of the WEBNET network , 2010 .

[111]  J. Šílený,et al.  Source mechanisms of the 2000 earthquake swarm in the West Bohemia/Vogtland region (Central Europe) , 2013 .

[112]  T. Plenefisch,et al.  Temporal variations of focal mechanisms in the Novy Kostel focal zone (Vogtland/NW-Bohemia)—comparison of the swarms of 1994, 1997 and 2000 , 2003 .

[113]  Ragnar Slunga,et al.  Stress tensor inversion using detailed microearthquake information and stability constraints: Application to Ölfus in southwest Iceland , 1999 .

[114]  E. Jelínek,et al.  Recurrent Cenozoic volcanic activity in the Bohemian Massif (Czech Republic) , 2011 .

[115]  Vladimir Schenk,et al.  Geodynamic pattern of the West Bohemia region based on permanent GPS measurements , 2009 .