Electronic Supplement To

ELECTRONIC SUPPLEMENT TO

The Comparison of Macroseismic Intensity Scales

by

R.M.W. Musson, G. Grünthal and M. Stucchi

Preface

This supplement consists of the actual full text of the most important intensity scales discussed in this paper, for ease of reference. Definitive versions are not always straightforward. The scales presented here are as follows:

Rossi-Forel: As discussed by Davison (1921), the Italian and Swiss versions of this scale differed somewhat. Davison at first referred to his own intensity scale as “Rossi-Forel”, and other variants may also exist. Here, Davison’s translation of the Swiss version (which he describes as the most commonly used) is reproduced.

Mercalli-Cancani-Sieberg: A number of modern versions of this scale can be found, in Italian, on various web pages. The version given here is the original 1912 version, translated by Davison (1921) from Sieberg’s original text. This is fuller than the versions currently circulating, and is of particular historical interest.

Modified Mercalli: As mentioned in the main text of the paper, versions of this scale are legion. The most important is that of Richter (1958), which is the version given here.

Medvedev-Sponheuer-Karník: Although different versions of the MSK scale were published between 1964 and 1981, the differences are fairly inconsequential. The last version is given here.

Japanese Meteorological Agency: The JMA scale of 1996 was published in the form of a table, with intensity degrees down the side and categories of effect along the top. This has been reformatted in a more conventional way for presentation here, and the wording edited slightly to improve the English translation. The scale was further modified in March 2009.

European Macroseismic Scale: Because of the inclusion of graphical elements, this scale is included as a pdf of the original pages that contain the core part of the scale. The full scale is also available as a pdf at http://tinyurl.com/cp7dc2 in both English and French versions, with Spanish and Chinese versions forthcoming. A short version of the scale is available in English, French, German, Spanish, Czech, Dutch, Greek, Hungarian, Lithuanian, Norwegian and Portuguese.

THE ROSSI-FOREL (RF) INTENSITY SCALE

1884 version, translated by Davison (1921) from Archives des Sciences Physiques et Naturelle, vol 11, pp 148-149.

1 Recorded by a single seismograph, or by some seismographs of the same pattern, but not by several seismographs of different kinds; the shock felt by an experienced observer.

2 Recorded by seismographs of different kinds; felt by a small number of persons at rest.

3 Felt by several persons at rest; strong enough for the duration or direction to be appreciable.

4 Felt by several persons in motion; disturbance of movable objects, doors, windows; creaking of floors.

5 Felt generally by everyone; disturbance of furniture and beds; ringing of some bells.

6 General awakening of those asleep; general ringing of bells; oscillation of chandeliers, stopping of clocks; visible disturbance of trees and shrubs; some startled persons leave their dwellings.

7 Overthrow of movable objects, fall of plaster, ringing of church bells, general panic, without damage to buildings.

8 Fall of chimneys, cracks in the walls of buildings.

9 Partial or total destruction of some buildings.

10 Great disasters, ruins, disturbance of strata, fissures in the earth's crust, rock-falls from mountains.

THE MERCALLI-CANCANI-SIEBERG (MCS) INTENSITY SCALE

1912 version, translated by Davison (1921) from Gerland’s Beiträge zur Geophysik, vol 11, pp 227-239

1 Imperceptible. The shock is not felt by man; only the records of seismometers adapted for earthquakes of near origin, or of sensitive seismoscopes give notice of it.

2 Very slight. Only a few persons in perfect repose, especially those with sensitive nerves, feel the shock as a slight tremor or rocking. The shock is especially sensible on the upper floors of houses and very rarely on the ground floor. Also, the quiet of the night is favorable to its perception, if the observer is awake.

3 Slight. Even in densely populated districts, the shock is felt by only a few persons as a shaking like that produced by the rapid passing of a wagon. Occasionally, the duration, and perhaps also the direction, of the movement can be detected. Many only realize afterwards, in talking with others, that there has been an earthquake.

4 Moderate. Of persons in the open air, not many feel the earthquake. Indoors, many persons, but not all, recognize the trembling or slight rocking movement of furniture; glasses and crockery near together gently strike one another as they do when a heavily laden wagon is driven by on an uneven pavement; windows rattle; doors, joists, floors, and ceilings creak; liquids in open vessels are slightly moved. Alarm is hardly ever caused except in the case of persons who have already become nervous and anxious through the experience of other earthquakes. In a few cases, sleepers awake.

5 Rather strong. Even during the busiest hours of the day, the earthquake is felt by many persons in the open air. Indoors, the shaking of the whole building is generally noticed, the feeling being the same as when some heavy object (such as a sack or piece of furniture) falls in the house; or the observers move, together with chair, bed, etc., as in a ship on an agitated sea. Plants, the branches and weaker boughs of shrubs and trees sway visibly, as they do with a moderate wind. Freely hanging objects, such as curtains and lamps, but not heavy chandeliers, oscillate; small bells ring; the pendulums of clocks are stopped or swing more widely according as the direction of the shock is at right angles or parallel to the plane of oscillation; similarly, stopped pendulum clocks are set going; the striking spring of clocks sounds; electric lights fail to act when contact of the conducting wire is made; pictures rattle against the walls or are displaced; small quantities of liquid are spilt out of wellfilled open vessels; ornaments, small standing frames fall and also objects leaning against the wall; even light furniture may be somewhat shifted from its place, rattling of furniture; doors and windowshutters open or shut; windowpanes crack. Sleepers as a rule are awakened. A few persons run into the open air.

6 Strong. The earthquake is felt by everyone with alarm, so that very many persons run into the open air, many thinking that they must fall. Liquids move violently, pictures fall from the walls, books, etc., from shelves, unless the direction of the shock is parallel to that of the walls; numerous vessels are broken; a few pieces of stable furniture are shifted or overturned; church bells and church clocks strike. In a few solidly built midEuropean houses there are cracks in the plaster, which is detached here and there in fragments from the roof and walls. In poorly built houses, the damage is greater, but still not of a serious nature.

7 Very strong. Considerable damage is done to furniture through the upsetting or breaking even of heavy pieces. Even large church bells strike. The surfaces of rivers, ponds, and lakes are disturbed, and the mud at the bottom stirred up. A few slips of sandy and gravelly coasts. The level of water in wells is changed. Notwithstanding their solid construction, many midEuropean houses suffer moderate damage; there are slight fractures in walls, large pieces of plaster crumble down, tiles fall, pantiles are loosened and slip down. Chimneys are damaged by cracks and by the falling of weather moulding and stones; chimneys in bad condition break off at the roof and injure it. Badly fastened decorations fall down from towers and high buildings. In framework buildings, and especially in their partition walls, the damage to the plastering is great. Buildings that are badly built or out of repair suffer seriously in the same way; wooden fences, sheds, high enclosure walls, cottages and even churches, minarets of mosques, etc., in many country districts of southern Europe, fall down to a greater or less extent. Earthquakeproof buildings, such as most of the stone and wooden houses in Japan, and the wood and wattled buildings, which are used in such great quantities in tropical earthquake districts, remain quite undamaged.

8 Ruinous. The trunks of trees, of palms especially, sway as with a strong wind. Even the heaviest pieces of furniture are shifted some distance or overturned. Statues, etc., near the ground, such as those in churches, churchyards, public parks, etc., either rotate on their pedestals or fall. Stone enclosurewalls are split and thrown to the ground. Notwithstanding their solid construction, midEuropean houses suffer serious damage, with gaping cracks in the masonry; in some cases, they collapse partly; most chimneys fall; church towers and factory chimneys especially so suffer, and, by their fall, neighboring houses may be more seriously damaged as if by the action of the shock alone; exceptionally wellbuilt factory chimneys are only fractured and displaced in their upper portions. Earthquakeproof buildings (such as those of Japan) show, slight damage, such as fractures, the crumbling of plaster, etc. (see degree 7, midEuropean houses), and wooden houses crack considerably in their joints. Rotten posts of Malayan stakehuts break. Slight cracks in the ground near steep slopes and in damp soil; a few outflows of water carrying small quantities of sand or mud.

9 Disastrous. Solidly built houses of European construction are seriously damaged, so that a large number becomes uninhabitable, a few fall completely or nearly so. Framework buildings are displaced on their stone foundations, on account of which they are under certain conditions damaged. Earthquakeproof buildings made of stone show considerable damage, the walls of wooden ones reveal gaps and cracks, old wooden houses are loosened in their frames.

10 Destructive. Most stone and framework buildings are overthrown together with their foundations, even firstclass brick walls show dangerous cracks, but the percentage of those of midEuropean construction is larger than in the case of earthquakeproof buildings. Even wellbuilt wooden houses and bridges suffer serious damage, a few are even demolished. Embankments, dams, etc., are more or less considerably damaged. Iron railwaylines are slightly bent. Conduit pipes (gas, water, etc.) in the ground are rent or compressed. Fissures and undulating folds are formed in the asphalt of the streets. Loose, and especially damp, ground shows fissures up to several decimeters in width; especially near watercourses, there may be parallel fissures from onehalf to threequarters of a meter wide. Not only does loose ground slide down from cliffs as landslips, but also rockslides fall into the valleys from the mountains, from the banks of rivers and even steep coasts whole parts break off, and on flat coasts masses of sand and mud are displaced, by which substantial changes in the form of the ground are wrought. The level of water springs is changed. From rivers, canals and lakes, water is thrown on to the banks.

11 Catastrophe. Stone buildings of whatever kind practically no longer stand. Even solid buildings of wood or wattling are only in a few cases able to survive, especially near lines of faulting. Bridge-buildings, though large and securely constructed, are destroyed by the breaking off of massive stone piers or fracture of iron shafts. Yielding wooden floors, however, are sometimes less damaged. Embankments and dams are quite torn asunder, frequently for long distances. Iron rails are strongly bent and compressed. The kind and amount of damage to roads depends on the nature of the foundations. Conduit pipes in the ground are completely severed and rendered useless. The most varied and very considerable morphological changes of the ground are noticed, which are closely defined by the nature of the ground; wide fissures and cracks are formed, the derangements in the horizontal and vertical directions being specially important in soft and watery ground. There is also the appearance in various forms of water carrying sand and mud. Landslips and rocksfalls are numerous.

12 Great catastrophe. No work of human hands remains standing. The derangements and transformations of the ground attain the grandest dimensions. Even in rocky ground, faults of considerable depth are formed, with great horizontal movements and numerous fissures. Dock cliffs break, rockfalls, landslips, collapse of river banks or shore are numerous and widespread. Underground and surface waters in consequence undergo the most various derangements; waterfalls are formed, lakes are dammed, rivers diverted, etc.

THE MODIFIED MERCALLI (MM) INTENSITY SCALE

1956 version, from Richter (1958)

Definitions:

Masonry A: Good workmanship, mortar, and design; reinforced, especially laterally, and bound together by using steel, concrete, etc.; designed to resist lateral forces.

Masonry B: Good workmanship and mortar; reinforced, but not designed in detail to resist lateral forces.

Masonry C: Ordinary workmanship and mortar; no extreme weaknesses like failing to tie in at corners, but neither reinforced nor designed against horizontal forces.

Masonry D: Weak materials, such as adobe; poor mortar; low standards of workmanship; weak horizontally.

1 Not felt. Marginal and long period effects of large earthquakes.

2 Felt by persons at rest, on upper floors, or favourably placed.

3 Felt indoors. Hanging objects swing. Vibration like passing light trucks. Duration estimated. May not be recognised as an earthquake.

4 Hanging objects swing. Vibration like passing of heavy trucks; or sensation of a jolt like a heavy ball striking the walls. Standing motor cars rock. Windows, dishes, doors rattle.Glasses clink. Crockery clashes. In the upper range of 4, wooden walls and frame creak.