Only detected by seismographs, not felt by persons.
Detected indoors by a few persons, particularly on the upper floors of buildings.
Detected indoors by several persons: windows may vibrate and objects swing.
Detected out of doors by a few persons and indoors by many; crockery rattles and floors and ceilings creak as they would if a heavily laden lorry were passing along a cobbled street.
Detected by the whole population of a locality. Awakens many sleepers. Causes liquids to spill. Makes suspended objects swing considerably and small objects move. Some bells ring.
Awakens all sleepers. Frightened people leave their homes. The shock makes all bells ring and lighting fitments swing. Clocks stop. Trees shake, books and small objects fall off shelves and furniture. In badly built dwellings roughcast surfaces crack and plasterwork falls.
General alarm, but well-built structures suffer no damage. Church bells ring. Cracks appear in some buildings. Chimneys in a poor state of repair fall and may damage roofs. Windows are broken. The mud in ponds is stirred up. Waves form on some watercourses. Variations occur in the level and width of sources of water. There are landslips on river banks and cracks appear in roads. Dwellings in tropical areas made of interwoven leaves and branches and the wooden houses of Japan remain intact.
General alarm and panic. Gaping cracks appear in well-built structures. Tree branches break off. Furniture moves about or is overturned, lighting fitments are damaged. Fissures several centimetres wide appear in the ground. Lake water becomes muddy. New lakes may be formed. Springs may disappear or appear and their level and capacity may change several times. Church belfries and factory chimneys are most damaged. Rocks fall from mountain slopes. Driving is made difficult. Statues twist round on their pedestals or fall.
General panic. Partial or total destruction of about 50% of buildings. Numerous cases of damage to furniture and objects in houses. Animals flee. Monuments and statues fall. Reservoirs are damaged. Some underground pipes are broken.
Most stone buildings are destroyed. Solid wooden buildings and bridges suffer damage and some are destroyed. Water and gas mains are broken. Cracks appear in the streets. Fissures are formed in loose ground and landslides occur along slopes and river banks. The water of lakes and watercourses is thrown up on to the banks.
Stone buildings completely destroyed. Solid structures of timber and branches only survive in isolated cases. Even the best-built bridges are destroyed. Railway rails are twisted. Dykes disintegrate.
No manmade structures survive. Changes in topography occur: fault slips, important horizontal displacements, mountain landslides, lake formation, the appearance of new watercourses, etc.
¹Some countries use the Rossi_Forel of one to ten. The Richter scale measures the magnitude of an earthquake, i.e. the energy relesed. Above Richter magnitude 5.5 damage is generally caused.