EMSEV-DEMETER JOINT WORKSHOP IGAR September 7-12, 2008 Bucharest SINAIA, ROMANIA GEODYNAMIC TORSION PROCESS OF THE GEODYNAMIC TORSION PROCESS OF THE SEISMOGENIC RELIC SLAB AND THE SEISMOGENIC RELIC SLAB AND THE INTERMEDIATE DEPTH SEISMICITY OF THE INTERMEDIATE DEPTH SEISMICITY OF THE VRANCEA ZONE VRANCEA ZONE Dumitru STANICA and Maria STANICA Dumitru STANICA and Maria STANICA
OUTLINE: OUTLINE: SEISMIC ACTIVE VRANCEA ZONE; GEOTECTONIC SEISMIC ACTIVE VRANCEA ZONE; GEOTECTONIC OVERVIEW: OVERVIEW: - - CRUSTAL MAP (Sandulescu and CRUSTAL MAP (Sandulescu and Visarion Visarion, 2000); , 2000); - DEEP GEODYNAMIC MODELS: DEEP GEODYNAMIC MODELS: - Wenzel et al., 1998: CRC (Germany)+ RGVE (Romania) groups; 1. Wenzel et al., 1998: CRC (Germany)+ RGVE (Romania) groups; 1. Linzer Linzer, PANCARDI, 2000; , PANCARDI, 2000; 2. 2. Sperner et al., 2005; et al., 2005; 3. Sperner 3. Martin et al., 2006 4. 4. Martin et al., 2006 Zadeh, 2005 , 2005 5. 5. Zadeh THE ELECTRICAL CONDUCTIVITY ANOMALY - - THE ELECTRICAL CONDUCTIVITY ANOMALY TRANSEUROPEAN SUTURE ZONE AND ACTIVE FAULTS TRANSEUROPEAN SUTURE ZONE AND ACTIVE FAULTS (ELECTROMAGNETIC DATA): : (ELECTROMAGNETIC DATA) CEMES (Central Europe Mantle geoElectrical geoElectrical Structures) NATO Structures) NATO- -Project (2001 Project (2001- -2003) : 2003) : 1. CEMES (Central Europe Mantle 1. - 1D and 2D 1D and 2D lithospheric lithospheric resistivity models; resistivity models; - 3D images w ith mantle conductance distribution - 3D images w ith mantle conductance distribution - Lithospheric Lithospheric peculiarities on the Romanian territory: peculiarities on the Romanian territory: 2. 2. 1D, 2D models (including resistivity/phase response functions) - 1D, 2D models (including resistivity/phase response functions) - - 3D tomographic images; 3D tomographic images; - Carpathian electrical conductivity anomaly 3. Carpathian electrical conductivity anomaly 3. 4. TransEuropean TransEuropean Suture Zone (TESZ) Suture Zone (TESZ) 4. Geodynamic model Vrancea zone 5. Geodynamic model Vrancea zone 5.
GEOTECTONIC OVERVIEW GEOTECTONIC OVERVIEW CRUSTAL MAP (Sandulescu and CRUSTAL MAP (Sandulescu and Visarion Visarion, 2000) , 2000) Vrancea zone 1. Precambrian East European Platform crust; 2. Precambrian Moesian Platform crust; 3. Paleozoic Scythian Platform crust; 4. Cimmerian-North Dobrogea crust; 5. “Transylvanian” type crust; 6. “Pannonian” type crust; 7. Depth to Moho; 8. Main deep faults (mostly transcrustal); 9. Position of the suture zones at the Moho level ; 10. Seismic active Vrancea zone 11. Magnetotelluric profiles
Deep Geodynamic Models- -Vrancea zone Vrancea zone Deep Geodynamic Models Wenzel et al., 1998 CRC (Germany)+ RGVE (Romania) groups
DEEP GEODYNAMIC MODELS DEEP GEODYNAMIC MODELS Wenzel et al., 1998: CRC (Germany)+ RGVE (Romania) groups Wenzel et al., 1998: CRC (Germany)+ RGVE (Romania) groups
DEEP GEODYNAMIC MODELS DEEP GEODYNAMIC MODELS Wenzel et al., 1998: CRC (Germany)+ RGVE (Romania) groups Wenzel et al., 1998: CRC (Germany)+ RGVE (Romania) groups
DEEP GEODYNAMIC MODELS DEEP GEODYNAMIC MODELS HYPOTHETICAL LITHOSPHERIC CROSS - SECTION SHOWING THE CONCENTRATION OF EARTHQUAKES IN THE VRANCEA AREA AND THEIR RELATIONSHIP TO A SINKING SLAB IN THE UPPER MANTLE (Linzer, PANCARDI, 2000)
DEEP GEODYNAMIC MODELS DEEP GEODYNAMIC MODELS Gvirtzman, 2003
DEEP GEODYNAMIC MODELS DEEP GEODYNAMIC MODELS
DEEP GEODYNAMIC MODELS DEEP GEODYNAMIC MODELS Top: Geodynamic evolution of plate subduction in SE Romania since the late Miocene (12 Mil.years ago) (Sperner et al., 2005) Bottom : Tomographic image of the subducted slab as high velocity body viewed from SSW (Martin et al., 2006)
Alik Ismail Zadeh, 2005
TESZ - - Electromagnetic data TESZ Electromagnetic data CEMES (Central Europe Mantle CEMES (Central Europe Mantle geoElectrical Structure) NATO- - geoElectrical Structure) NATO Project Project B. Deep Electromagnetic Soundings of B. Deep Electromagnetic Soundings of the Mantle around the TESZ the Mantle around the TESZ
TESZ - - Electromagnetic data TESZ Electromagnetic data
TESZ - TESZ - LITHOSPHERIC PECULIARITIES ON THE ROMANIAN LITHOSPHERIC PECULIARITIES ON THE ROMANIAN TERRITORY : TERRITORY : 2D MT models and response functions 2D MT models and response functions Resistivity response of the 2D model DEPTH[Km] ρ 2D-tomographic image ( ) along the blue line (Dobrogean Orogen) perpendicular to the Peceneaga-Camena (P-C) active fault
2D MT models and 3D tomographic images 2D MT models and 3D tomographic images PHASE DISTRIBUTION (B-POLARIZED MODE) FALCIU TG. SECUIESC TULNICI PANCIU ESE SW WNW NE l l l l l 0.3 - 0.5 - F 1.0 - C TROTUS F - 2.0 - P 3.0 - C 5.0 - E 10.0 - C RELIC 20.0 - A SLAB 30.0 - SQRT(T) PHASE DISTRIBUTION (E-POLARIZED MODE) TG. SECUIESC TULNICI FALCIU PANCIU ESE SW NE l l l l l WNW 0.3 - 0.5 - 1.0 - TROTUS F 2.0 - F C C 5.0 - - E P 10.0 - C RELIC A 20.0 - SLAB 30.0 - 2 D MODEL VRANCEA Z ONE SQRT(T) Profile : Cata lina - Tulnici - Panciu (Forw ard modeling-finite e le ment code) 3 D magnet otelluric t omographic image in t he Vrancea zone on the 3-50km depth int er val; green plane is t he Peceneaga-Camena fault; blue plane is the Trotus fault .
Carpathian Electrical Conductivity Anomaly (CECA) Carpathian Electrical Conductivity Anomaly (CECA) CONTINENTAL LITHOSPHERE - THE EUROPEAN PLATFORM 0 0 200 400 600 800 1000 1200 -50 CONTINENTAL LITHOSPHERE- PHANEROZOIC TERRANES (Transylvanian Basin) -100 Depth (km) 0 Series1 0 200 400 600 800 -150 -20 -40 36 140 -200 3 E P DEPTH (km) 111 Series1 120 -60 42 44 -250 52 16 15 22 23 RESISTIVITY (ohm.m) 100 7 394 42 20 4 -80 88 21 15 5 80 56 3 219 Focsani 12 -100 Brasov 26 60 5 2 13 -120 2 40 RESISTIVITY (ohm .m ) 7 Buzau 5 20 4 2 40 60 80 100 120 140 160 180 200 220 Resistivity distribution at 100km depth Resistivity distribution at 100km depth
TESZ TESZ - - - LITHOSPHERIC PECULIARITIES ON THE LITHOSPHERIC PECULIARITIES ON THE LITHOSPHERIC PECULIARITIES ON THE TESZ TESZ LITHOSPHERIC PECULIARITIES ON THE ROMANIAN TERRITORY : ROMANIAN TERRITORY : : MT MT MT Data Data Data ROMANIAN TERRITORY ROMANIAN TERRITORY : MT Data BRITTLE-DUCTILE TRANSITION ZONE IN THE LOWER CRUST 49 18 - 28 km TESZ 30 - 38 km VRANCEA 40 - 50 km ZONE 48 EAST EUROPEAN PLATE INTRA-ALPINE 47 PLATE 46 45 MOESIAN PLATE 44 43 20 21 22 23 24 25 26 27 28 29 30 0 80 160 240 320km Stanica, Stanica - - 1999, 2001 1999, 2001 Stanica, Stanica
Magnetotelluric tomography (resistivity) at 100 km depth Magnetotelluric tomography (resistivity) at 100 km depth EP EP - - European Platform; European Platform; w hite diamonds - - Trans Trans- -European Suture Zone; European Suture Zone; w hite diamonds blue cross- -w ises w ises - - Pecenaga Pecenaga- -Camena Camena fault; fault; blue cross w hite rectangle w hite rectangle - - horizontal cross horizontal cross- -section through the relic slab. section through the relic slab.
Magnetotelluric tomography (resistivity) at 150 km depth. Magnetotelluric tomography (resistivity) at 150 km depth. EP - EP - European Platform; European Platform; White rectangle - horizontal cross- -section through the relic slab. section through the relic slab. White rectangle - horizontal cross
Deep Geodynamic Model (50 - -150km) 150km) - - Vrancea zone Vrancea zone Deep Geodynamic Model (50 - torsion process of the relic slab torsion process of the relic slab TOMOGRAFIES - MT- - TOMOGRAFIES MT Descending Asthenospheric Currents Stanica et al., 2004 GEO-MOTION GROUP
Geodynamic model- - Vrancea zone Vrancea zone Geodynamic model INTERMEDIATE DEPTH EQ INTERMEDIATE DEPTH EQ hypocenters hypocenters MoP epicenters epicenters Geodynamic model elaborated beneath the crustal level. The thick black lines represent CECA; yellow circles are intermediate depth earthquakes(Stanica et al., 2004)
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