Disaster intensity scales

With the eyes of the world on Haiti after yesterday's devastating magnitude 7.0 earthquake, I thought I'd review the various disaster intensity scales.

Richter Magnitude Scale
Developed by American scientist Charles Richter (1900-1985), the Richter scale quantifies the amount of seismic energy released by an earthquake. Each number of the scale multiplies the shaking amplitude by 10, so a 5.0 earthquake is 10 times stronger than a 4.0. Descriptions from Earthquakefacts.net follow.

1-2: Shaking is rarely felt by people.
2-3: Only people at rest feel the shaking, especially if they are on the upper floors of a building.
3-4: Many people indoors feel the shaking, but most people do not recognize it as an earthquake.
4: Most people indoors and some outdoors notice shaking. Dishes, windows, and doors rattle. Walls creak. Parked cars rock.
4-5: Felt by almost everyone. Many sleeping people wake up. Liquid splashes out of glasses. Small objects are knocked over. Some dishes and windows break.
5-6: Felt by all. People have trouble walking. Some heavy furniture moves. Dishes break, and pictures fall off walls. No damage to buildings.
6: People have trouble standing. Furniture breaks. Plaster and bricks may crack and fall. Noticeable waves on ponds. Church bells ring. Considerable damage to poorly built buildings.
6-7: People have trouble driving cars. Walls, chimneys, and tree branches break and fall. Some poorly built buildings may collapse. Tall structures may twist and fall.
7: People panic. Underground pipes may break, and well-built buildings are considerably damaged. The ground may crack.
7-8: The ground cracks. Water splashes over the banks of rivers and canals. Railroad tracks bend.
8: Highways, railroads tracks, bridges and underground pipelines are destroyed. Most buildings collaspe. Large cracks appear in the ground.
8 or greater: Destruction of buildings and transportation systems. Almost everything is destroyed. The surface of the ground moves in waves or ripples. The ground is covered with cracks and holes.

The Enhanced Fujita Scale
Replacing the original Fujita scale introduced by American scientist Ted Fujita (1920-1998), the Enhanced Fujita scale rates the strength of tornadoes in the U.S. based on the damage they cause. Descriptions from Wikipedia follow.

EF0 65–85mph winds, minor damage: Peels surface off some roofs; some damage to gutters or siding; branches broken off trees; shallow-rooted trees pushed over.
EF1 86–110mph winds, moderate damage: Roofs severely stripped; mobile homes overturned or badly damaged; loss of exterior doors; windows and other glass broken.
EF2 111–135mph winds, considerable damage: Roofs torn off well-constructed houses; foundations of frame homes shifted; mobile homes completely destroyed; large trees snapped or uprooted; light-object missiles generated; cars lifted off ground.
EF3 136–165mph winds, severe damage: Entire stories of well-constructed houses destroyed; severe damage to large buildings such as shopping malls; trains overturned; trees debarked; heavy cars lifted off the ground and thrown; structures with weak foundations blown away some distance.
EF4 166–200mph winds, devastating damage: Well-constructed houses and whole frame houses completely leveled; cars thrown and small missiles generated.
EF5 >200mph winds, extreme damage: Strong frame houses leveled off foundations and swept away; automobile-sized missiles fly through the air in excess of 100 m (300 ft); steel reinforced concrete structure badly damaged; high-rise buildings have significant structural deformation.

The Saffir-Simpson Hurricane Wind Scale
Developed by American civil engineer Herbert Saffir (1917-2007) and American meteorologist Bob Simpson (b. 1912), the Saffir-Simpson scale classifies Western Hemisphere tropical cyclones by the intensities of their sustained winds, starting at 74mph, for use in measuring potential damage. Descriptions from the National Hurricane Center follow.

Category One: Sustained winds 74-95mph. Damaging winds are expected. Some damage to building structures could occur, primarily to unanchored mobile homes (mainly pre-1994 construction). Some damage is likely to poorly constructed signs. Loose outdoor items will become projectiles, causing additional damage. Persons struck by windborne debris risk injury and possible death. Numerous large branches of healthy trees will snap. Some trees will be uprooted, especially where the ground is saturated. Many areas will experience power outages with some downed power poles.
Category Two: Sustained winds 96-110mph. Very strong winds will produce widespread damage. Some roofing material, door, and window damage of buildings will occur. Considerable damage to mobile homes (mainly pre-1994 construction) and poorly constructed signs is likely. A number of glass windows in high rise buildings will be dislodged and become airborne. Loose outdoor items will become projectiles, causing additional damage. Persons struck by windborne debris risk injury and possible death. Numerous large branches will break. Many trees will be uprooted or snapped. Extensive damage to power lines and poles will likely result in widespread power outages that could last a few to several days.
Category Three: Sustained winds 111-130mph. Dangerous winds will cause extensive damage. Some structural damage to houses and buildings will occur with a minor amount of wall failures. Mobile homes (mainly pre-1994 construction) and poorly constructed signs are destroyed. Many windows in high rise buildings will be dislodged and become airborne. Persons struck by windborne debris risk injury and possible death. Many trees will be snapped or uprooted and block numerous roads. Near total power loss is expected with outages that could last from several days to weeks.
Category Four: Sustained winds 131-155mph. Extremely dangerous winds causing devastating damage are expected. Some wall failures with some complete roof structure failures on houses will occur. All signs are blown down. Complete destruction of mobile homes (primarily pre-1994 construction). Extensive damage to doors and windows is likely. Numerous windows in high rise buildings will be dislodged and become airborne. Windborne debris will cause extensive damage and persons struck by the wind-blown debris will be injured or killed. Most trees will be snapped or uprooted. Fallen trees could cut off residential areas for days to weeks. Electricity will be unavailable for weeks after the hurricane passes.
Category Five: Sustained winds greater than 155mph. Catastrophic damage is expected. Complete roof failure on many residences and industrial buildings will occur. Some complete building failures with small buildings blown over or away are likely. All signs blown down. Complete destruction of mobile homes (built in any year). Severe and extensive window and door damage will occur. Nearly all windows in high rise buildings will be dislodged and become airborne. Severe injury or death is likely for persons struck by wind-blown debris. Nearly all trees will be snapped or uprooted and power poles downed. Fallen trees and power poles will isolate residential areas. Power outages will last for weeks to possibly months.