I • • 11 Terrestrial Fluids, Earthquakes and Volcanoes: The Hiroshi Wakita Volume III Edited by Nemesio M. Pérez Sergio Gurrieri Chi-Yu King Yuri Taran Birkhäuser Basel · Boston · Berlin Reprint from Pure and Applied Geophysics (PAGEOPH), Volume 165 (2008) No. 1 Editors: Nemesio M. Pérez Sergio Gurrieri Environmental Research Division Istituto Nazionale di Geofisica e Instituto Tecnológico y de Energias Vulcanologia Renovables Sezione di Palermo Polígono Industrial de Granadilla s/n V. Ugo La Malfa, 153 38611 Granadilla, Tenerife 90146 Palermo Canary Islands Italy Spain e-mail: [email protected] e-mail: [email protected] Yuri Taran Chi-Yu King Volcanology Department Earthquake Prediction Research, Inc Institute of Geophysics 381 Hawthorne Ave. UNAM Los Altos, CA 94022 3000, Av. Universidad USA Mexico D.F., 04510 e-mail: [email protected] Mexico e-mail: taran@geofisica.unam.mx Library of Congress Control Number: 2006043001 Bibliographic information published by Die Deutsche Bibliothek: Die Deutsche Bibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data is available in the Internet at <http://dnb.ddb.de> ISBN 978-3-7643-8737-2 Birkhäuser Verlag AG, Basel · Boston · Berlin This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, re-use of illustra- tions, recitation, broadcasting, reproduction on microfilms or in other ways, and storage in data banks. For any kind of use permission of the copyright owner must be obtained. © 2008 Birkhäuser Verlag AG Basel · Boston · Berlin P.O. 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TCF ∞ Printed in Germany ISBN 978-3-7643-8737-2 e-ISBN 978-3-7643-8738-9 9 8 7 6 5 4 3 2 1 www.birkhauser.ch PURE AND APPLIED GEOPHYSICS Vol. 165, No. 1, 2008 Contents 1 Introduction N.M.Pe´rez,S.Gurrieri,C.-Y.King,Y.Taran 5 SpatialandTemporalChangesofGroundwaterLevelInducedby ThrustFaulting Y.Chia,J.J.Chiu,Y.-H.Chiang,T.-P.Lee,C.-W.Liu 17 GeochemicalMonitoringofGeothermalWaters(2002–2004)alongtheNorth Anatolian Fault Zone, Turkey: Spatial and Temporal Variations and RelationshiptoSeismicActivity S.Su€er,N.Gu€lec¸,H.Mutlu,D.R.Hilton,C.C¸ifter,M.Sayin 45 Coupling Between Seismic Activity and Hydrogeochemistry at the Shillong Plateau,NortheasternIndia A.Skelton,L.Claesson,G.Chakrapani,C.Mahanta,J.Routh, M.Mo¨rth,P.Khanna 63 RadonChangesAssociatedwiththeEarthquakeSequenceinJune2000inthe SouthIcelandSeismicZone P.Einarsson,P.Theodo´rsson,A´.R.Hjartardo´ttir,G.I.Guðjo´nsson 75 CO Degassing over Seismic Areas: The Role of Mechanochemical Produc- 2 tionattheStudyCaseofCentralApennines F.Italiano,G.Martinelli,P.Plescia 95 ChangesintheDiffuseCO EmissionandRelationtoSeismicActivityinand 2 aroundElHierro,CanaryIslands E.Padro´n,G.Melia´n,R.Marrero,D.Nolasco,J.Barrancos,G.Padilla, P.A.Herna´ndez,N.M.Pe´rez 115 SO EmissionfromActiveVolcanoesMeasuredSimultaneouslybyCOSPEC 2 andmini-DOAS J.Barrancos,J.I.Rosello´,D.Calvo,E.Padro´n,G.Melia´n,P.A.Herna´ndez, N.M.Pe´rez,M.M.Milla´n,B.Galle 135 Underground Temperature Measurements as a Tool for Volcanic Activity MonitoringintheIslandofTenerife,CanaryIslands A. Eff-Darwich, J.Coello, R.Vin˜as, V.Soler,M.C. Martin-Luis,I.Farrujia, M.L.Quesada,J.delaNuez 147 Carbon Dioxide Discharged through the Las Can˜adas Aquifer, Tenerife, CanaryIslands R.Marrero,D.L.Lo´pez,P.A.Herna´ndez,N.M.Pe´rez 173 ListofPublications HiroshiWakitawasborninNishinomiya(Hyogo,Japan)onSeptember29,1936,andisactuallyanEmeritus Professor at The University of Tokyo (Japan). He graduated with B.Sc., M.Sc. and Ph.D. from Gakushuin University(Tokyo)in1962,1964and1968,respectively.He wasaResearcherattheJapanAtomicEnergy ResearchInstitution,Tokyo(1964–68),ResearchAssociateatOregonStateUniversity,Corvallis,USA(1968– 71),ResearchAssociateattheUniversityofTokyo(1971–77),LectureatTheUniversityofTokyo(1977–78), AssociateProfessoratTheUniversityofTokyo(1978–86),ProfessoratTheUniversityofTokyo(1986–97), and Professor at the Gakushuin Women’s College, Tokyo (1998–2007). He was also the Director of the Laboratory for Earthquake Chemistry at The University of Tokyo (1988–97), Associate Editor of Applied Geochemistry(1992–96),PresidentoftheGeochemicalSocietyofJapan(1992–93),andVice-presidentofthe GeochemistryResearchAssociation(1996).HereceivedtheMiyakePrizeforhiscontributionsonthefieldof geochemistryfromtheGeochemistryResearchAssociationin1989. Pureappl.geophys.165(2008)1–3 (cid:2)Birkha¨userVerlag,Basel,2008 0033–4553/08/010001–3 Pure and Applied Geophysics DOI10.1007/s00024-007-0295-3 Introduction Terrestrial Fluids, Earthquakes and Volcanoes: The Hiroshi Wakita Volume III is a special publication to honor Professor Hiroshi Wakita for his scientific contributions to science, which have been closely linked with one of the major objectives of the 2008 International Year for the Earth Planet. Reducing natural risks in active tectonic and volcanicenvironmentsbysearchingforanddetectingearlywarningsignaturesrelatedto earthquakes and volcanic eruptions has been a major research goal for Hiroshi Wakita. ThevolumeIIIconsistsofnineoriginalpaperswrittenbyresearchersfromTaiwan,Italy, Turkey, Iceland, USA, Sweden, India and Spain dealing with various aspects of the role of terrestrial fluids in earthquake and volcanic processes, which reflect Prof. Wakita’s wide scope of research interests. The volumes I and II consist of 17 and 10 original contributions which were published in Pure and Applied Geophysics on May 2006 and December 2007, respectively. These Pure and Applied Geophysics Hiroshi Wakita volumesshouldbeusefulforactiveresearchersinthesubjectfield,andgraduatestudents who wish to become acquainted with them. Professor Wakita founded the Laboratory for Earthquake Chemistry in April 1978 with the aim of establishing a scientific base for earthquake prediction by means of geochemical studies, and served as its director from 1988 until his retirement from the university in 1997. He has made the laboratory a leading world center for the study of earthquakesand volcanic activities by means ofgeochemical and hydrological methods. Together with his research team and numerous foreign guest researchers whom he attracted, he has made many significant contributions in the above-mentioned scientific fields of interest. This achievement is a testimony for not only his scientific talent, but also his enthusiasm, his open-mindedness, and his drive in obtaining both human and financial support. TheninecontributionsofthisvolumeIIIarearrangedintotwogroups.Thefirstgroup of five papers deals with the movement and signatures of terrestrial fluids related to earthquakesandactivetectonicregions. Thepaper byCHIAet al.describesthe observed changesofgroundwaterlevelinducedbythrustfaultingduringtheM 7.6,1999Chi-Chi w earthquakerecordedin276monitoringwellsinTaiwan.Mostoftheobservedcoseismic falls appeared near the seismogenic fault as well as other active faults, while coseismic rises prevailed removed from the fault. The following paper by SU¨ER et al. presents the results of the 2002–2004 geochemical monitoring period of terrestrial fluids in geothermal fields located along an 800-km long E-W transect of the North Anatolian 2 N.M.Pe´rezetal. Pureappl.geophys., Fault Zone (NAFZ) in Turkey, in order to both characterize the chemical nature of the individual fields and identify possible temporal variations associated with localized seismic activity. The paper by SKELTON et al. describes transient hydrogeochemical anomalies observed in a granite-hosted aquifer, which is located at a depth of 110-m, northoftheShillongPlateau,Assam,India.Theironsetsprecededmoderateearthquakes onDecember9,2004(M = 5.3)andFebruary15,2005(M = 5.0),respectively,206 W W and 213 km from the aquifer. The observation of these two hydrogeochemical events with the only two M C 5 earthquakes in the study area argues in favor of cause- W and-effect seismic-hydrogeochemical coupling. The paper by EINARSSON et al. describes theobservedradonchangesingeothermalwatersfromdrillholesrelatedtoanearthquake sequence at the transform plate boundary in South Iceland, which included two magnitude 6.5 earthquakes in June 2000. The authors emphasize that these radon anomalieswerelargeandunusualifcomparedtoa17-yearhistoryofradonmonitoringin this area. The paper byITALIANO et al. provides field observations andnew experimental data for the potential of the unexpected additional CO gas source production by 2 mechanical energy applied to carbonate rocks in active tectonic regions beside mantle- derived CO or CO produced by thermometamorphism. Data collected during the 2 2 seismiccrisiswhichstrucktheCentralApenninesin1997–1998haveshownanenhanced CO flux not associated with the presence of mantle or thermometamorphic-derived 2 fluids. This earthquake-tectonic-related paper is then followed by four additional contribu- tionsdealingwithobservationsrelatedtovolcanicprocesses.ThepaperbyPADRo´Netal. describes the continuous monitoring of diffuse CO emission at El Hierro volcanic 2 system, Canary Islands (Spain) and the observed geochemical anomalies before the occurrence of low magnitude seismic events in and around the volcanic island in 2004. The authors applied the material Failure Forecast Method (FFM) on the diffuse CO 2 emissiondata toforecastsuccessfullythe firstseismic eventthat tookplaceinElHierro in2004.Thefollowingvolcano-relatedpaperbyBARRANCOSetal.providesadditionaland recent SO emission data from eight active volcanoes: Santa Ana (El Salvador), San 2 Cristo´balandMasaya(Nicaragua),ArenalandPoa´s(CostaRica),Tungurahua(Ecuador), SierraNegra(Gala´pagos)andEtna(Italy).ThispaperalsodescribesacomparisonofSO 2 emissionmeasurementsbyCOSPECandmini-DOASshowingthatmostoftheobserved relativedifferenceswerelowerthan10%.ThepaperbyEFF-DARWICHetal.describesthe spatial distribution of groundwater temperatures in Tenerife (Canary Islands) thanks to the vast network of *1.500 subhorizontal tunnels which provide most of the water resourcesfortheisland.Geological,hydrologicalandvolcanologicalcharacteristicsseem to be responsible for the actual groundwater temperature spatial distribution which has been characterized during a quiescent period, in order to detect changes in heat flow related to volcanic activity. The last volcano-related paper is also related to the groundwater system at Tenerife, Canary Island (Spain). The paper by MARRERO et al. provides an estimation of the water mass balance and the CO budget in Las Can˜adas’ 2 aquifer; the largest aquifer on the island. The relatively high dissolved inorganic carbon Vol.165,2008 Introduction 3 content in the groundwaters explains the ability of this aquifer to dissolve and transfer magmatic CO , even during quiescence periods. 2 The guest editorial team would like to thank all the contributors, and reviewers involved, who are listed below: R.M. Azzala, Werner Balderer, Alain Bernard, Emily Brodsky, Giorgio Capasso, Carlo Cardellini, Yeeping Chia, Antonio Eff-Darwich, WilliamsC.Evans,CinziaFederico,FaustoGrassa,JensHeinicke,PedroA.Herna´ndez, David Hilton, GeorgeIgarashi,Kohei Kazahaya,NaojiKoizumi,PaoloMadonia,Rayco Marrero, Norio Matsumoto, Agnes Mazot, Eleazar Padro´n, Antonio Paonita, J. W. Rudnicki, Francesco Sortino, Jean-Paul Toutain, Nick Varley, Giuseppe Vilardo and VivekWalia.SpecialthanksareduetoKennethMcGee,whoservedasco-guesteditorin TheHiroshiWakitavolumeI,forhissupportofthisspecialissue,toPedroA.Herna´ndez for his great assistance to the Guest-Editorial team, and to Renata Dmowska, without whosemarvellousandtremendoussupporthelpthethirdspecialvolumewouldnothave been possible. Nemesio M. Pe´rez Chi-Yu King Environmental Research Division Earthquake Prediction Research, Inc. Instituto Tecnolo´gico y de Energ´ıas 381 Hawthorne Ave. Renovables (ITER) Los Altos, CA 94022 Tenerife, Canary Islands USA Spain Yuri Taran Sergio Gurrieri Institute of Geophysics Istituto Nazionale di Geofisica e Universidad Nacional Auto´noma de Vulcanologia, V. Ugo La Malfa Me´xico (UNAM) 153 - 90146 Palermo Mexico D.F 04510 Italy Mexico Pure appl. geophys. 165 (2008) 5-16 ' Birkhauser Verlag, Basel, 2008 0033^553/08/010005-1 2 (cid:149) D,,,. ^ ^» H Ar^r^li^r l r-^^,^l.woi..o DOT 10.1007/S00024-007-0293-5 ’ ^^^^ ^" ^ Applied Geophysics Spatial and Temporal Changes of Groundwater Leve l Induced by Thrust Faulting YEEPIN G CHIA/ JESSIE J. CHIU,^ YI-HSUA N CHIANG/ TSAI-PIN G LEE/ and CHEN-WUM G LIU"^ Abstract(cid:151)Changes of groundwater level, ranging from a fall of 11.10 m to a rise of 7.42 m, induced by thrust faulting during the 1999 M ^ 7.6, Chi-Chi earthquake have been recorded in 276 monitoring wells in Taiwan. Most coseismic falls appeared near the seismogenic fault as well as other active faults, while coseismic rises prevailed away from the fault. Coseismic groundwater level rises and falls correlated fairly well with hypocentral distance in the vicinity of the thrust fault. W e found a major difference of coseismic changes in wells of different depths at most multiple-wel l stations. The recovery process of coseismic groundwater level changes is associated with the confining condition of the aquifer. Cross-formational flow is likely to play an important role in groundwater level changes after the earthquake. In the hanging wall of the thrust fault, an abnormal decline of groundwater level was observed immediately before the earthquake. The underlying mechanism of the unique preseismic change warrants further investigation. Key words: Groundwater, Chi-Chi earthquake. Thrust fault, Coseismic, Postseismic, Preseismic. 1. Introduction Water level in a well-confine d aquifer could be sensitive to crustal strain (BREDEHOEFT , 1967). Field observations have shown a correlation between the estimated tectonic strains and the coseismic changes of well water level during the 1974 Izu-Hanto- Oki earthquake (WAKITA , 1975). Variations of groundwater level in seismic regions have been used to monitor crustal deformation and to search for an earthquake precursor (BAKU N and LINDH , 1985; KISSI N et al., 1996). Coseismic groundwater level changes have been reported in many places around the world (MONTGOMER Y and MANGA , 2003), howeve r most changes are either sparsely distributed or concentrated in a few spots. Postseismic changes may reflect the subsurface flow in response to coseismic changes or permeability changes (ROELOFFS, 1998; WAN G et al., 2004). The observation of the flow process, particularly after small changes, is often impeded by pumping or other hydrologic factors. Preseismic changes are seldom ^ Department of Geosciences, National Taiwan University, Taipei 106, Taiwan. E-mail: [email protected] ^ Atomi c Energy Council, Yonghe , Taipei 234, Taiwan. ^ Department of Bioenvironmen t System s Engineering, National Taiwan University, Taipei 106, Taiwan. 6 Y . Chia et al. Pure appl. geophys., reported (ROELOFFS and QUILTY , 1997; KOIZUM I and TSUKUDA , 1999), and the supporting evidence and underlying mechanism of their relations to fault deformation or earthquakes are not clear (KIN G et al, 2000). Whil e studies pertaining to the distribution and process of earthquake-related hydrologic phenomena are hampered by limited data, preliminary clues have been obtained by examining groundwater level changes recorded by a dense monitoring well network in the vicinity of a thrust fault ruptured during a large earthquake in Taiwan. Here we use monitoring records before, during, and after the earthquake to enhance our understanding of the spatial and temporal distribution as well as the possible mechanisms of groundwater level changes induced by thrust faulting. 2. Earthquake and Monitoring Wells On 21 Septembe r 1999, an earthquake of Mw 7.6 occurred near the town of Chi-Chi in central Taiwan at 1:47 a.m. local time. The hypocentral depth was estimated to be 10 km (SHIN et al., 2000). The best fitting focal mechanism has a nodal plane with a strike of 5(cid:176), a dip of 34(cid:176) and a rake of 65(cid:176)(CHAN G et al, 2000; KA O and CHEN, 2000). A s shown in Figure 1, widespread surface rupture resulted from thrusting along the Chelungpu fault extended approximately 100 km in the north-south direction (ANGELIE R et al, 2003). The hanging wall is on the east side of the thrust fault. Field investigations and GPS data indicated that the hanging wall move d as much as 10.1 m laterally and 8 m vertically. In contrast, up to 1.5-m lateral displacement and 0.26-m vertical displacement were observed in the footwall (Y u et al., 2001). In the coastal plain of Taiwan, the second generation network of monitoring wells had been installed since 1992 for improving groundwater resource management. A t the time of the Chi-Chi earthquake, 377 monitoring wells were operational in Taiwan. In the vicinity of the seismogenic fault, all wells, except one, are located in the footwall (west side) of the fault. Groundwater level is recorded by the digital data logger at one-hour interval. Som e wells equipped with the analog data logger also provide continuous records. Al l of the monitoring wells were screened in highly permeable sand or gravel layers. An y changes of groundwater level in the aquifer can, therefore, be quickly reflected by changes of water level in the monitoring well. 3. Spatial Distribution of Coseismic Groundwater Changes Coseismic changes of groundwater level in central western Taiwan due to the Chi-Chi earthquake have been discussed by CHIA et al. (2001) and WAN G et al. (2001). The mechanisms of these coseismic changes have been discussed by LEE et al. (2002), WAN G et al. (2003), KOIZUM I et al. (2004) and LA I et al. (2004). Tw o types of coseismic changes of water level were observed: oscillatory changes and persistent changes.