Grades by Richter Scale

Horizontal Velocity

Cm/sec.

Earthquake Effects

3

-

Nobody feels the earthquake except some people under very special circumstances.

3.5

2 - 3

It is felt only by some people, and the things that are freely hanging tremble.

4

4 - 7

It is clearly felt in houses as it causes shakings such as the ones caused by the metro.

4.5

7 - 15

It is felt as if a truck collides with a building, and vehicles shake obviously.

5

15 - 30

Wall portraits fall, unbalanced things are turned over, and the pendulum of watches stops.

5.5

30 - 70

It is felt by everyone, heavy pieces of furniture move, and chimneys and weak buildings crack.

6.0

70 - 150

Cracking is remarkable in poor-concrete buildings and loadbearing walls.

6.5

150 - 300

Cracking is simple in earthquake-resistant installations. There is a big crack in buildings having loadbearing walls. Buildings separate from columns and beams, and some of them move out. Statues, minarets, chimneys and fences fall. Heavy pieces of furniture are turned over, and the level of well water changes.

7

300 - 700

Cracking is obvious in earthquake resistant installations, concrete installations. In addition, some buildings separate from their bases, and the soil splits clearly.

7.5

700 - 1500

Most buildings having loadbearing walls are destroyed, and some concrete installations and their bases are ruined. The earth is split apart into big and serious cracks, and railways are bent. Sides of rivers and canals slide, and the sand soil and the silt move.

8

1500 - 3000

Most buildings having loadbearing walls collapse, and concrete buildings are destroyed. Bridges fall, making in the earth breaks swallowing people and vehicles. Water and sewage networks collapse altogether.

8.5

300 - 600

The destruction is mass, as seismic waves can be seen on the ground obviously, and heavy objects fly in the air.