1. Earthquakes Prof. David Alexander Global Risk Forum Davos

2. Physical aspects

4. A typical year of earthquakes (1996) Magnitude

7. frequencies present in the waves

8. maximum amplitude of the waves

12. areas of volcanic activityand geothermal fluxes.

14. inverse (compressional movement)

15. transcurrent(lateral, strike-slip)

18. The elastic rebound theory of H.F. Reid

19. Types of seismic wave:- Body waves: P, primus, compression or pressure waves - longitudinal S, secundus, shear waves - transverse Surface waves: L, Love S, Stoneley R, Rayleigh C, channel R waves travel at 92%of the speed of S waves, which travel at 58%of the speed of P waves, etc.....

20. The main kinds of seismic wave Primus (pressure) 'P' waves Body waves Secundus (shear) 'S' waves Love 'L' waves Surface waves Rayleigh 'R' waves

21. LOVE WAVES EPICENTRE RAYLEIGH WAVES FAGLIA SHEAR WAVES PRESSURE WAVES HYPOCENTRE FRONT OF THE WAVES

23. Seismometers

24. Accelerometers

26. Moment Magnitude scale, MW,the world standard.

27. In earthquakes energy expenditure is proportional to magnitude: the points on the magnitude scale have a logarithmic relationship in terms of energy release - thus: M8= 31.6 x M7

28. Relationship between magnitude and other variables

29. World seismic activity over a typical eight-year period Number of earthquakes Magnitude

31. 5 minutes Time S waves with different frequences Distance 1000 km Epicentre Slowing down of P and S waves with distance from epicentre

32. stn. 1 stn. 2 epicentre stn. 3 Localisation of epicentre on the basis of the arrival times of seismic waves

33. Epicentres and faults located for the Bam, Iran, earthquake of 26 Dec. 2003.

34. Effect of different geological materials in amplifying seismic waves

35. Extract from a seismic microzonation map showing different shaking potentials

36. A typical sequence of aftershocks after a major seismic event (Northridge, California, 1994) Number of earthquake per day all others m<5 Days after the earthquake

37. Colfiorito earthquake swarm, central Italy September - December 1997 Days after earthquake Days after earthquake Associated seismic intensities Days after earthquake

38. MCS intensities for 23-11.1980 southern Italian earthquake M6.8

39. NEW ZEALAND Intensities with a probability of 50% of returning within 50 years Return periods of earthquakes with intensities of at least MM=VI

40. Comparative data on four earthquakes

41. Consequences of Earthquakes - and significant issues -

42. Construction failure poses the greatest threat to life in earthquakes

43. Structural integrity: a building's physical adequacy for its intended purpose Failure: total or partial collapse, or the destruction or non-functionality of a building.

46. regularity of building form

51. 85(24%) collapsed partially

53. repair buildings permanently

54. design and construct buildings antiseismically.

57. The largest urban seismic risk is in Istanbul and Tehran Major earthquakes represent an enormous urban search-and-rescue (USAR) challenge

58. The international relief system is hugely expensive and inefficient $1,000,000 per life saved!

63. DISASTER VICTIM Search and rescue UNINJURED INJURED Medical assistance Public health measures IMPROVEMENT OF CONDITION WORSENING OF CONDITION HEALTHY INFECTED Medical aid HEALTHY IMPROVEMENT OF CONDITION WORSENING OF CONDITION Mortuarial and funeral services DEATH DISEASES INJURIES

64. Injuries Emergency room injuries Hospital admissions No damage to buildings Damage to buildings Source: Linda Bourque, UCLA

65. In the Italian Irpinia-Basilicata earthquake of 1980 hospitals collapsed. In the El Salvador earthquake of 1986 hospitals collapsed. In the El Salvador earthquake of 2001 hospitals collapsed. In the Bam, Iran, earthquake of 2003 hospitals collapsed. ....haven't we learnt anything at all?

66. "At Olive View Medical Center, two buildings collapsed in 1971, and three people died, including two patients on life-support systems that failed when auxiliary generators did not start. The third was an ambulance driver who was crushed by a falling wall. Olive View was an 888-bed hospital then. It had only been open a month when the quake hit. Because of extensive damage, the hospital was rebuilt, with attention to strengthening it against any future quake. But it was much smaller. Now it has a capacity of 377 patients." [Sylmar, California, history file]

67. Of the 58 fatalities caused by building damage, 50 occurred in hospitals. The worst damage to medical facilities occurred at the Veterans Administration Hospital in Sylmar where two large buildings collapsed. Even though the hospital site was right on the edge of the heavily urbanized San Fernando Valley, it took one hour and 22 minutes before a fire department helicopter happened to spot the collapses and send help. The reason for such a delay? The phones didn’t work, the hospital’s radio was in one of the collapsed buildings, and the first message orally delivered by a hospital staff member to a nearby government facility was confused with an already received report of damage to a different nearby hospital. [Reitherman 2004]

73. loss of medical and surgical capacity

76. surgical and curative (fixed ordiminished in the short term).

79. Disaster planning for the medical centre Disaster planning for the system of medical centres Disaster planning for the external environment Disaster in the medical centre Disaster in the system of medical centres Co-ordinated EMS Disaster plans Disaster in the external environment

80. Helicopter links Ambulance routes Emergency bus transportation Telecommunications links T1 T2 Primary triage point Secondary triage points Pulmonary specialists Hospital I Hospital II T2 Staging area T2 T1 Burns unit Disaster T2 Secondary treatment centre Incident command post Incident commander Mortuary Emergency operations commander Emergency operations centre Next-of-kin Coroner

81. IMPACT ON THE COMMUNITY RISK OF EARTHQUAKE Characteristics of the event: magnitude, duration, location of epicentre, level ofground acceleration Buildings, drinking water, sewerage, public transport, public buildings, hospitals, fire stations, etc. Local geological characteristics Population distribution and density Aftershocks Socio-economic characteristics RISK OF EARTHQUAKE Landslides Previous experience of risk Floods Casualties, economic damage; type, costs times of reconstruction Fires Level of community preparedness

82. Thank you for your attention!