1. Europlanet Graz, 1-2 June 2007 1 Gerald Duma Central Institute for Meteorology and Geodynamics Vienna, Austria AN ELECTROMAGNETIC PROCESS REGULATES EARTHQUAKE ACTIVITY Workshop Earthquakes: Ground-based and Space Observations

2. Europlanet Graz, 1-2 June 2007 2 Studies performed  10-year research pogramme  Several cooperations in Europe, Asia, America  Effect verified for many earthquake zones worldwide  Plausible interpretation and model

3. Europlanet Graz, 1-2 June 2007 3 Observations (1996) – daily range AUSTRIA M  2.5, 1901-1990 Geomagnetic Observatory

4. Europlanet Graz, 1-2 June 2007 4 Duma, Vilardo (INGV), 1998 Geomagnetic Observatory Observations (1997) – daily range Mt. VESUVIUS volcanic eqs, area 10 x 10 km, 1.8  M  3.1, 1972-1996, 1400 events

5. Europlanet Graz, 1-2 June 2007 5 A seismic daily cycle  Aristoteles  Pliny the Elder,  79 A.D. eruption of Mt.Vesuvius  Tams, 1926  Conrad, 1932  Shimshoni, 1972  Lipovics, 2000, 2005  Schekotov & Molchanov, 2005  Poorly investigated in recent decades, no interpretation given yet

6. Europlanet Graz, 1-2 June 2007 6 A seismic daily cycle 3 sub-periods 20th century AUSTRIA M  2.5 May 31 – June 18, 1997 Earthquake swarm in Austria, region IMST

7. Europlanet Graz, 1-2 June 2007 7 A seismic daily cycle  Observed in many main seismic regions  Earthquakes M  5 and M  6  A very powerful geodynamic process acting!

8. Europlanet Graz, 1-2 June 2007 8 Geomagnetic Observatory Obs WIK, comp N ‚ secular variation‘ AUSTRIA M  3.1 (Io  5°) Observations (1996) – long term

9. Europlanet Graz, 1-2 June 2007 9 Mechanism, models?  Dependence on Local Time  Process related to sun  A mechanism which penetrates the whole Earth‘s lithosphere  Tides ?  No!  High energy mechanism  Can a few nT influence tectonic performance?

10. Europlanet Graz, 1-2 June 2007 10 The electromagnetic model  Geomagnetic variations in a conductive lithosphere  Maxwell‘s equations (E-H)  ‚Telluric currents‘ associated with all natural geomagnetic variations (frequency range from min – solar cycle)

11. Europlanet Graz, 1-2 June 2007 11 The electromagnetic model  Telluric currents and forces F = e. [ v e. B ] F... mechanic force vector e... electron charge v e... velocity vector B... magnetic field vector ‚Lorentz force‘ F B veve e

12. Europlanet Graz, 1-2 June 2007 12 The electromagnetic model  Magnetic observatories monitor:  H(t) ~  I H (t) ~  F V (t) vertical force

13. Europlanet Graz, 1-2 June 2007 13 The electromagnetic model r P1 P2 I2 ≠ I1  Regional mechanic moment, torque Tr

14. Europlanet Graz, 1-2 June 2007 14 The electromagnetic model  The gradient of  H(t) reflects the change of regional torque  Tr(t) (azimuth Az) Torque axis P

15. Europlanet Graz, 1-2 June 2007 15 Energy – diurnal variation T = MM x H A large scale current field, covering  1/3 of the northern Earth‘s hemisphere  The dayside Sq induced lithospheric current vortex (Chapman, Bartels, 1940; Matsushita, 1968)

16. Europlanet Graz, 1-2 June 2007 16 Energy – diurnal variation  The mechanic moment of Sq for a single loop (Duma, Ruzhin, 2003) The example demonstrates: The deformation energy provided to the lithosphere by a single current loop, radius 1500 km and current 10 kA, is equivalent to the energy of an earthquake M 5,1.

17. Europlanet Graz, 1-2 June 2007 17 Energy – diurnal variation  60% of total moment concentrates in a 30° segment H I

18. Europlanet Graz, 1-2 June 2007 18 Modelling the electromagnetic effect  Data for  H(lat,long) to compute gradient Daily variation: hourly mean values  Model of Sq telluric current vortex  Regional observatory data (lat i, long i ) Long term: annual mean values  Retrieved from IGRF, 1900-2010 (grid data)  Regional observatory data (lat i, long i )

19. Europlanet Graz, 1-2 June 2007 19 Case studies – Regions AustriaTaiwan CaliforniaBaikal region

20. Europlanet Graz, 1-2 June 2007 20 Case studies – Austria (M ≥ 3.2, Gradient  H – N10W) Gradient  H from IGRF10 (1900-2010) Diurnal range Long term 1900 - 2003 Gradient  H from Sq-Model

21. Europlanet Graz, 1-2 June 2007 21 Case studies – Taiwan (M ≥ 5, Gradient  H – N55E) Gradient  H from IGRF10 (1900-2010) Diurnal range Long term Gradient  H from Sq-Model 1973 - 1998

22. Europlanet Graz, 1-2 June 2007 22 Case studies – Baikal area (M ≥ 5, Gradient  H – N00E) Gradient  H from IGRF10 (1900-2010) Diurnal range Long term Gradient  H from Sq-Model 1900 - 1980 2001 - 2006

23. Europlanet Graz, 1-2 June 2007 23 Case studies – California (M ≥ 6, Gradient  H – N30E) Gradient  H from IGRF10 (1900-2010) Diurnal range Long term Gradient  H from Sq-Model 1970 - 2005

24. Europlanet Graz, 1-2 June 2007 24 Case study – earthquakes 2004-2006 2004 08 01 – 2006 12 31, M  5 S-ITALY IONIAN IS AEGEAN

25. Europlanet Graz, 1-2 June 2007 25 Case study – earthquakes 2004-2006 IONIAN ISLANDS Seismic activity – Local Time M  5 1965 – 1989 (25 yrs, PDE) 1990 – 2003 (14 yrs, PDE) 2004 08 01 – 2006 12 31 M  5 n = 11 (PDE) Gradient  H (N85E)

26. Europlanet Graz, 1-2 June 2007 26 Case study – earthquakes 2004-2006 1910 – 1980 (72 yrs, INGV) 2004 08 01 – 2006 12 31 M  5 n = 4 (PDE) 2004 08 01 – 2006 12 31 M  4.5 n = 11 (PDE) S-ITALY Seismic activity – Local Time M  5

27. Europlanet Graz, 1-2 June 2007 27 Case study – earthquakes 2004-2006 Aegean Sea 2004 08 01 – 2006 12 31 M  5 n = 5 (PDE) Crete Aegean Sea vs. Crete Seismic activity – Local Time M  5 2004 08 01 – 2006 12 31 M  5 n = 4 (PDE) Aegean Sea / Strongest events 2004-2006: 2006 01 08 UT=11 34 55.64 lat=36.31° long=23.21° d=66 km M=6.7

28. Europlanet Graz, 1-2 June 2007 28 Case study – earthquakes 1963-2006 Aegean M  4, n = 956 (NOA) Ionian Is M  4, n = 237 (NOA) Gradient  H from IGRF10 AEGEAN vs. IONIAN IS Seismic activity – long term M  4

29. Europlanet Graz, 1-2 June 2007 29 Case study – earthquakes 1963-2006 Ionian Is M  5, n = 36 (NOA) S-Italy M  5, n = 57 (INGV+PDE) S-ITALY vs. IONIAN IS Seismic activity – long term M  5

30. Europlanet Graz, 1-2 June 2007 30 Novel aspects  External sources – causing geomagnetic variations - strongly influence seismic activity (trigger)  Origins: solar radiation, ionosphere, Sq ; magnetic dynamo  Answer to daily rhythm of seismic activity (LT)  Monitoring the process: easy by geomagnetic observatories  Predictability: systematic diurnal, seasonal, secular variations (IGRF 2010)  Not yet investigated: influence of magnetic storms  Faster monitoring of variations by space observations ?

31. Europlanet Graz, 1-2 June 2007 31 Observations (1997) – long term Duma, Vilardo (INGV), 1998 n: annual number of eqs M  1.8, 1972-1996 sf: annual number of solar flares (10 3 ) Duma, Vilardo (INGV), 1998 Mt. VESUVIUS volcanic eqs, area 10 x 10 km, 1.8  M  3.1, 1972-1996, 1400 events

32. Europlanet Graz, 1-2 June 2007 32 Tectonic settings & faulting mechanisms in Greece (Dewey et al., 1973 / A. Tzanis, UOA, 2003)

33. Europlanet Graz, 1-2 June 2007 33 Model of Sq telluric current vortex  Fits observed Sq-variations at observatories  Computes grad  H(LT)

34. Europlanet Graz, 1-2 June 2007 34  H – current density

35. Europlanet Graz, 1-2 June 2007 35 The electromagnetic model  Magnetic observatories monitor horizontal force Fh C (t)

36. Europlanet Graz, 1-2 June 2007 36 Energy – diurnal variation  Sq: solar controlled, heating, ionization, tides (Chapman, Bartels, 1940)