Judge scale

with the international judge scale can be uniformly determined the strength of an earthquake by instruments. The indicated value ( the Magnitude = size class) is considered thereby as measure to the soil movement in the Hypozentrum (and/or. for the set free seismic energy ina certain frequency range). One point more on the scale means an about tenfold higher excursion and the 32-fache Energiefreisetzung (logarithmic rise).

A strength (Magnitude) of 2 or is designated less than micro earthquake, is often not noticed there it of humanswill can and only by local seismographs one seizes. Quake with a strength of approximately 4.5 and more highly enough are strong, in order by seismographs in the whole world to be seized. However the strength must lie over 5, over asmoderate earthquake to be regarded.

Due to its definition the judge scale is upward unlimited theoretically, the physical characteristics of the earth's crust makes however an occurrence of earthquakes of the strength 9.5 or more highly almost not possibly, since the rock do not store enough energycan and before reaching this strength unloads themselves. The plates zerbröseln as it were. The strongest earthquake since the introduction of the judge scale occurred 1960 in the Pacific ocean before the coast of Chile: It original evaluated with 8,6, later however thenrevalued by different institutions (including US Geological Survey) on 9,5. An earthquake similarly strong with 9,2 occurred four years later in March 1964 in the Prince William sound in Alaska. The last one of 9.0+ quake occurred to 26. December 2004 before Sumatra (see also: Earthquake in the Indian ocean 2004).

The judge scale was developed of Charles Francis judge and Beno good mountain at the California institutes OF Technology 1935 as mathematical aid to the comparison of the strength of earthquakesand initially as ML-scale (Magnitude local one) designates.

Für die Beschreibung der Stärke und Zerstörungskraft eines Erdbebens wird hingegen häufig die modifizierte und weiterentwickelte Mercalliskala des Italieners Giuseppe Mercalli (1850-1914) verwendet.

On the so-called. MSK scale (Medvedev Sponheuer Karnik scale) becomesthe strength of a quake indicated in 12 intensities. The gradation orients itself both at subjective and at objective criteria.

Judge and Mercalli earthquake - scale

strength after judge

strength after Mercalli



number of quake per year

tons TNT


0 to 1.9


only by instruments registerable


(4..4000)< math> \ cdot< /math> 10 6

very large number

of 2 to 2.9


only from very few, resting humans noticeably; free-hanging pendulums swing easily


(4..90)< math> \ cdot< /math> 10 9


3 to 3.9


only from fewHumans noticed oscillations; Vibration comparably a driving past truck; quiet Flirren of together-standing glasses

of 30-700

(0,1..3)< math> \ cdot< /math> 10 12


4 to 4.9

IV to V

is noticed by most humans; free pendulum swings clearly; Glasses and plates rattle, window shutter swing; turned off carsswings easily; smallest damage.

(1-22)< math> \ /math< 10> 3 (
small nuclear weapon ) (

4..90) cdot< math> \ cdot< /math> 10 12


5 to 5.9


perception by all humans with frights; many humans leave their houses; Chimneys can collapse; Furniture moves; individual tears in the finery; there is thoseDanger of injuries

(30-700)< math> \ cdot< /math> 10 3

(middle nuclear weapon)

(0,1..3)< math> \ cdot< /math> 10 15


6 to 6.9


is experienced by all humans concerned with large fright; also in the driving car noticeably; partial panic possible; individual shocks arise; Humans leaverapidly their houses; Buildings can suffer substantial damages; it can come to collapses; Trees vary as with strong wind; it gives often hurt; there is danger for life and limb; at coasts tsunami possible.

(1-22)< math> \ /math< 10> 6 ( large nuclear weapon ) (

4..90) cdot< math> \ /math< 10> cdot15


7 to 7.9

X to XI

widespread panic; Humans try to come into panic into the free; acute mortal danger in buildings; only few buildings stop; Columns in the soil tear up; there is dead ones and hurt one; Water and gas linesbreak in large quantities; partial catastrophic effects; at coasts destroying tsunami possible.

(30-700)< math> \ /math< 10> 6 ( meteorite 100-200 m) /p

< cdot>

(0,1..3)< math> \ /math< 10> 18 18


to 8.9 XII


cdot; all buildings uninhabitable; acute mortal danger within and outside of buildings; surface covering destruction; onCoasts catastrophic, high up to 40 tsunami meters possible.

(1-22)< math> \ /math< 10> 9 ( meteorite 250-700 m) /p

< cdot>

(4..90)< math> \ /math< 10> 18 cdot

every 5 years quake

9.0 and over it


large disaster; Destruction like before and additionally: local lumps of earth shift; In parts “completeDestruction of the life ". Further possible: large shifts of the continental plates, “appearance, shifting or disappearing” regions/islands, education of new Subduktionszonen, change of the Erdnutation or the earth rotation speed.


- <p>

<p align= " CENTERS "> unknown; vermutl. all 10 to 100 years

approach can quake the logarithmic connection between energy and Magnitude be summarized with

< math>

M=2+ \ frac {2} {3} \ log_ {10} W \ textrm {\ quad and/or. \ quad} W=10^ {\ frac {3} {2} (M-2)}\, </math>

whereby M is the Magnitude and W the equivalent (explosive) energy in tons TNT.

seismograph moment Magnitude

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