CzechGeo workshop, IG ASCR, Prague, 22 November, 2017 Do West Bohemian earthquakes displace the surface ? Jan Mrlina and Michal Seidl Institute of Geophysics ASCR, Prague, Czech Republic N West Bohemia seismoactive region K a - Geology g rlo ra v ni y te Va p r lu y to n - Seismicity Epicentral zones of rift re 1 – Nový Kostel Oh 2 - Kraslice-Klingenthal Cheb 7 - Skalná b a sin C h e Mariánskéb Lázne Fault - M D L o F m a ž lic e g ra b e n E Variscan granitoid massifs Seismological network Neogene sedimentary basins earthquakes foci Qua terna ry volca noes principal tectonic faults towns other faults MLF ( Adopted after Horálek et al., 2000 ) uplifts (Variscan or older) What non-seismological data we may need ? • GPS, leveling, InSAR – surface dynamics • Groundwater level, CO2 – fluids dynamics • 4D Gravity – stress changes, pore pressure • Tilts – blocks dynamics • Volcanological research – magma activity • DEM analysis, gravity survey, . - tectonics Thanks to EPOS/CzechGeo Project we could mainly improve the observation, data transfer and storage of: GPS/GNSS, Tilts/Inclination, Groundwater level, Gravity, Precise levelling, Volcanic structures search 16 G ERM AN Y AD3 17 33 18 KRA SLI C E HRANIC E ADO RF Geodynamic 12 13 B. ELSTER network 9 14 52 58 LUBY 11 NK 32 10 4 AŠ B. BRAM BA C H 5 30 E 3 6 5 H3 P1 A 31 2 7 . Sk 2 8 2 1 SKA LN Á 1 50.167 N C Z E C H R E P. 34 57 F. LÁ ZN E N KYN ŠPERK n . O . 5 km Outer geodynamic network Inner geodynamic network Gravimetric connections Mariánské Lázně fault Hydrogeological boreholes Area of levelling network Epicentral areas Nový Additional gravity stations Kostel and Skalná G P S 1998 - 2000 No permanent trend determined from GPS, rather reversal movements NOKO KOPA IG CAS ??? Height difference 100 80 2IG 60 KOPA 40 20 ] 0 mm [ -20 -40 -60 -80 -100 9/11/2006 9/11/2007 9/11/2008 9/11/2009 9/11/2010 9/11/2011 9/11/2012 [date] Height difference 100 80 3IG 60 NOKO 40 20 ] 0 mm [ -20 -40 -60 -80 -100 9/11/2006 9/11/2007 9/11/2008 9/11/2009 9/11/2010 9/11/2011 9/11/2012 [date] Height difference 10 8 6 4 Unfortunately, we don’t2 see any significant vertical displacement over 10 mm ] 0 in the studied periodmm [ -2 3IG -4 -6 NOKO -8 Level. -10 9/11/2006 9/11/2007 9/11/2008 9/11/2009 9/11/2010 9/11/2011 9/11/2012 [date] Fault projection to surface Installation of permanent GPS station in Novy Kostel Mariánská Nový Kostel Karlovy vary Poustka Within CzechGeo we intend to set up new permanent GNSS station east of Novy Kostel (east of fault ?) Updating of GNSS data transfer form permanent observatory NKOS Trimble 5700 Receiver - measuring GPS data in 15s interval Teltonika RUT955 - Linux LTE Router GFU FTP server RPI Linux computer - 6h logging data from receiver - upload to GFU FTP server TELIS Linux processing server with GAMIT/GLOBK Gravity changes Point 7 6 5 4 3 sw arms Vertical displacements 11/93 reference 04/94 station G6 G5 10/94 3 _ G4 G3 05/95 2 6 12/95 1 05/96 0 -1 10/96 5 -2 3 02/97 -3 09/97 _ -4 4 03/98 _ -5 05/99 -6 5/94 5/95 6/96 7/97 6/98 6/99 6/00 10/00 1/01 6/01 7/02 7/03 8/04 7/05 10/99 06/00 09/00 12/00 Point 7 6 5 4 3 30 20 10 ) l 0 a G -10 o 06/00 - 10/99 r -20 c i m ( 20 G 10 d 0 Gravity changes are not caused -10 09/00 - 06/00 -20 K r u š n é h o r y M t s. by vertical movements C h e b b a s i n SWW NEE MLF 1 2 3 4 5 6 West Bohemia: Relation of - Gravity changes - GPS displacements - Seismicity Within CzechGeo frame we wish to install a permanent gravimeter in Novy Kostel Historical precise levelling 1967-1956 12 Kraslice 10 8 Krajková 6 Sokolov 4 Frant. Lázně 2 Cheb 2 4 6 8 10 12 Precise levelling Main focal zone ( mm ) 1500 Nový Kostel area Vertical displacements ? 5 1997 - 1998 1000 NKC 4 ( no earthquake 3 swarm ) 2 500 N ? 1 0 0 -1 ? -2 -500 ? -3 area of interpolation division line -4 -1000 of different displacements -5 -500 0 500 1000 1500 2000 2500 3500 Nový Kostel - levelling: 6/2000 - 10/2000 contour map of vertical displacements 3000 no data in 10/2000 3-D view Earthquake swarm 2500 [mm] “Autumn 2000” 2000 3 2 1500 1 seism.obs. N.Kostel 0 1000 -1 -2 -3 500 -4 -5 0 -6 Luby -7 -500 -8 Similar vertical -9 surface movements -1000 -10 N.Kostel levelling points like in -1500 -1000 -500 0 500 1000 1500 2000 2500 3000 January 1997 Sokolov SW seism.obs. N.Kostel [mm] no data in 10/2000 no data in 10/2000 NE Novy Kostel precise levelling network 2017 - 1994 +10 mm ? Does this mean that even small earthquake swarms may produce recordable geodynamic signals ??? With support of CzechGeo, our Group of Geodynamics constructed a prototype of a new 2-component tide-sensitive tiltmeter in 2016-2017 ! This is not it !!! Anomalous tilt to SW -1150 850 SKALNA Observatory: Tiltmeters data [10-3 arcsec] N - S [Geodynamics & EarthTide Group, Příbram] -1250 750 Raw data E - W - corrected for sharp shifts caused by earthquakes - precipitation effects not removed -1350 magnitude 650 M=3.9 precipitation 1 7 mm -1450 550 1.10.2008 3.10.2008 5.10.2008 7.10.2008 9.10.2008 11.10.2008 13.10.2008 15.10.2008 17.10.2008 19.10.2008 21.10.2008 23.10.2008 25.10.2008 27.10.2008 29.10.2008 31.10.2008 100 10 hrs before strongest event 80 Observatory SKALNA: Residual Tilts North 60 East 40 20 0 -20 -40 20081008 20081009 20081010 20081011 20081012 20081013 20081014 -60 -80 -100 10 / 2008 31.5.2014 M = 4.4 We have the following Partners to progress with dynamic, structural and tectonic models building • GPS, leveling, InSAR – surface dynamics (IG ASCR, GFZ) • Groundwater level, CO2 – fluids dynamics (IG ASCR, GFZ) • 4D Gravity – stress changes, pore pressure (IG ASCR, . ) • Tilts – blocks dynamics (Uni Jena, IG ASCR, Russian Academy) • Volcanological research – magma activity (IG ASCR, GFZ, Uni Leipzig, Museum Goerlitz, Bavarian Geol. Survey) • DEM analysis, gravity survey, . - tectonics (IG ASCR, . ) . and use the results for ICDP drilling planning, but also for practical use – spa, CO2 control, search for volcanoes, . In the memory of all those days, • MYMA when the volcanism sun is still little shining over the land falling asleep • Tilts under the soft foggy blanket • InSAR, GPS, Leveling and we are still observing • 4DG till late dark . • Magmatic activity, JM . • . fluids, groundwater, CO2 Cheb Basin, November 2016 .