IEC 60721-2-6:2022

IEC 60721-2-6 ®
Edition 2.0 2022-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Classification of environmental conditions –
Part 2-6: Environmental conditions appearing in nature – Earthquake vibration
and shock
Classification des conditions d'environnement –
Partie 2-6: Conditions d'environnement présentes dans la nature – Vibrations et
chocs sismiques
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IEC 60721-2-6 ®
Edition 2.0 2022-12
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Classification of environmental conditions –

Part 2-6: Environmental conditions appearing in nature – Earthquake vibration

and shock
Classification des conditions d'environnement –

Partie 2-6: Conditions d'environnement présentes dans la nature – Vibrations et

chocs sismiques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 19.040 ISBN 978-2-8322-6272-6

– 2 – IEC 60721-2-6:2022 © IEC 2022
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 General description of earthquake . 6
4.1 General . 6
4.2 Earthquake origin and propagation . 7
4.3 Earthquake behaviour . 7
4.4 Products on foundations . 7
4.5 Products in buildings and structures . 7
5 Seismic scales . 7
5.1 Definition of intensity and magnitude . 7
5.2 Examples of intensity scales . 8
5.3 Example of magnitude scale . 9
6 Description of the seismic environment by response spectra . 10
6.1 Response spectrum . 10
6.2 Ground response spectrum . 10
6.3 Required response spectrum . 11
7 Seismic activity zone classification . 11
Annex A (informative) Example of seismic activity zones . 16
A.1 Classification criteria of US Uniform Building Code . 16
A.2 World seismic activity zones classification according to UBC . 16
Bibliography . 25

Figure 1 – Acceleration record of the Irpinia-Basilicata-Italy earthquake (1980) . 12
Figure 2 – Model for composing a response spectrum . 13
Figure 3 – Response spectrum of the Calitri record of Irpinia earthquake (1980)
(Figure 1) for 2 % damping ratio value . 14
Figure 4 – Example of required response spectrum for ground motion . 15

Table 1 – Earthquake intensity scales for some countries/regions . 8
Table 2 – European Macroseismic Scale (EMS-98) . 9
Table 3 – Moment Magnitude Scale . 10
Table 4 – Seismic activity zones . 11
Table A.1 – Seismic activity zones definition according to UBC. 16
Table A.2 – Seismic activity zones classification according to UBC . 16

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
CLASSIFICATION OF ENVIRONMENTAL CONDITIONS –

Part 2-6: Environmental conditions appearing in nature –
Earthquake vibration and shock

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 60721-2-6 has been prepared by IEC technical committee 104: Environmental conditions,
classification and methods of test. It is an International Standard.
This second edition cancels and replaces the first edition published in 1990. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the main aim of this revision is to classify in a limited number of classes the seismic activity
level of the zone where the equipment could be installed;
b) the correlation between intensity scales, magnitude scales and peak ground acceleration is
deleted due to the scientific uncertainty to define such a correlation in a rigorous way;
c) updated scales are given both for intensity and for magnitude;

– 4 – IEC 60721-2-6:2022 © IEC 2022
d) the earthquake zone map, which was not usable in practice, is replaced by an annex giving
information about how to retrieve consistent peak ground acceleration distribution all over
the world;
e) with regard to identification of the peak ground seismic acceleration of the zone, where the
equipment could be installed, the user is made aware that national standards and laws can
apply.
The text of this International Standard is based on the following documents:
Draft Report on voting
104/946/FDIS 104/952/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
A list of all parts in the IEC 60721 series, published under the general title Classification of
environmental conditions, can be found on the IEC website.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
INTRODUCTION
This part of IEC 60721 is one of a series dealing with the following subjects:
– environmental parameters and their severities (IEC 60721-1);
– environmental conditions appearing in nature (IEC 60721-2);
– classification of groups of environmental parameters and their severities (IEC 60721-3).
This part of IEC 60721 is intended to be used as background material when selecting
appropriate severities of parameters relating to earthquakes for product application. Severities
given in IEC 60721-1 [1] should be applied.
More detailed information can be obtained from specialist documentation and from technical
literature, some of which is given in the bibliography.

___________
Numbers in square brackets refer to the Bibliography.

– 6 – IEC 60721-2-6:2022 © IEC 2022
CLASSIFICATION OF ENVIRONMENTAL CONDITIONS –

Part 2-6: Environmental conditions appearing in nature –
Earthquake vibration and shock

1 Scope
This part of IEC 60721 deals with environmental conditions appearing in nature related to
earthquake vibrations and shocks.
Its object is to define some fundamental properties and quantities for characterization of
earthquakes as background material for the severities to which products are liable to be
exposed during storage and use. The accelerations given are for ground surface conditions
only. Conditions related to structures are referred to but restricted to general case descriptions.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60068-3-3:2019, Environmental testing – Part 3-3: Supporting documentation and guidance
– Seismic test methods for equipment.
ISO 2041, Mechanical vibration, shock and condition monitoring – Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60068-3-3 and
ISO 2041 apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
4 General description of earthquake
4.1 General
Influences from earthquakes are vibrations which can be modelled as stochastic processes and
can affect products and provide stress in many ways.
This Clause 4 is intended to provide information on earthquake behaviour, and on the dynamic
performance of products during earthquakes. Numerical values given are typical and illustrative
but should not be considered as standard.

4.2 Earthquake origin and propagation
An earthquake occurs when stresses have accumulated to such a degree that they cause the
breaking of the earth's crust. These instabilities are located in areas known as active seismic
zones, in connection with a series of geological accidents such as troughs, oceanic ridges,
mountain ranges, volcanoes, ocean trenches, tectonic faults.
The sudden breaking releases elastic deformation energy which will spread from the hypocentre
in the form of three typical basic waves with different speeds:
– longitudinal volume waves which compress and expand the rock in the propagation
direction;
– transversal waves which shear the rock by distortion, perpendicular to the propagation;
– surface waves which are a combination of the two previous ones and subject to surface limit
conditions.
4.3 Earthquake behaviour
Earthquakes produce random ground motions which are characterized by simultaneous but
statistically independent horizontal and vertical components. A moderate earthquake can
persist for 15 s to 30 s; a severe earthquake for 60 s to 120 s. In general, the strong part with
the highest ground acceleration can last up to 10 s. The typical broadband random motion has
its maximum energy over a frequency range from 1 Hz to 35 Hz, and produces more damaging
effects from 1 Hz to 10 Hz. Usually the vertical component of the ground motion is assumed to
be between 67 % and 100 % of the horizontal.
NOTE Maximum acceleration is commonly used in design to reflect earthquake "strength" at a particular site.
4.4 Products on foundations
The typical broadband spectra which describe the ground motion indicate that multiple
frequency excitation predominates. The vibration nature of the ground motion (both horizontal
and vertical) can be magnified in foundation-mounted products. For any given ground motion,
the magnification depends on the characteristic frequencies of vibration of the system (soil,
foundation and product) and on the mechanism of damping.
4.5 Products in buildings and structures
The ground motion can be filtered and amplified by intervening building structures to produce
fluctuating sinusoidal floor motions. The typical narrowband spectra which describe a building
floor motion indicate that single frequency excitation can predominate. The dynamic response
of floor-mounted products can reach an acceleration many times that of the maximum ground
acceleration, depending on the system damping and characteristic frequencies of vibration. The
magnification and bandwidth depend on the dynamic response characteristics of each building
and product structure. Products sensitive to frequencies ranging from 1 Hz to 10 Hz are most
likely to be affected.
5 Seismic scales
5.1 Definition of intensity and magnitude
In seismology, earthquakes are classified with the aid of various scales according to their
intensity or magnitude.
Intensity scales are determined empirically and classify earthquakes in degrees of intensity
according to their effects. Intensity scales are based on the observed effects of the shaking,
such as the degree to which people or animals were alarmed, and the extent and severity of
damage to different kinds of structures or natural features.

– 8 – IEC 60721-2-6:2022 © IEC 2022
Intensity is here considered a classification of the severity of the ground shaking on the basis
of observed effects in a limited area. Intensity scales, and the concept of intensity itself, have
been evolving through the course of the last century. From a pure hierarchical classification of
effects more and more attempts have been made to develop intensity as a rough instrument for
measuring the shaking; at least, it has been used in this sense. Intensity is descriptive of the
earthquake effects, rather than analytical in the manner of an instrumental measurement.
Magnitude is related to the amount of seismic energy released at the hypocentre of the
earthquake. It is based on the amplitude of the earthquake waves recorded on instruments
which have a common calibration. The magnitude of an earthquake is thus represented by a
single, instrumentally determined value.
Both these scales, intensity and magnitude, can roughly correspond with certain values of
ground acceleration; their use for establishing test values is limited.
The relationship between the intensity scales and the acceleration level on products can only
be approximated on account of the following factors:
– the soil or rock conditions (including water saturation);
– the proximity to the earthquake activity;
– the conditions of the structure or base of the product.
Also the relationship between the magnitude scale and the peak ground acceleration is limited
by the following effects:
– the soil or rock base at the location;
– the focal depth of the earthquake;
– the duration of the earthquake activity.
5.2 Examples of intensity scales
Table 1 provides a list of different intensity scales adopted by some countries.
Table 1 – Earthquake intensity scales for some countries/regions
Country/Region Seismic intensity scale used
China Liedu Scale (GB/T 17742-2020)
Europe European Macroseismic Scale (EMS-98)
Hong Kong, China Modified Mercalli Scale (MM)
India Medvedev-Sponheuer-Karnik Scale
Israel Medvedev-Sponheuer-Karnik Scale (MSK-64)
Japan JMA Seismic Intensity Scale
Kazakhstan Medvedev-Sponheuer-Karnik Scale (MSK-64)
Philippines PHIVOLCS Earthquake Intensity Scale (PEIS)
Russia Medvedev-Sponheuer-Karnik Scale (MSK-64)
Taiwan, China Central Weather Bureau Seismic Intensity Scale
United States Modified Mercalli Scale (MM)

The European Macroseismic Scale EMS-98 is the first seismic intensity scale designed to
encourage co-operation between engineers and seismologists, rather than being for use by
seismologists alone. It comes with a detailed manual, which includes guidelines, illustrations,
and application examples. The short form of the European Macroseismic Scale (see Table 2),
abstracted from [2], is intended to give a very simplified and generalized view of the EMS.

Table 2 – European Macroseismic Scale (EMS-98)
EMS intensity Definition Description of typical observed effects (abstracted)
I Not felt Not felt.
II Scarcely felt Felt only by very few individual people at rest in houses.
III Weak Felt indoors by a few people. People at rest feel a swaying or
light trembling.
IV Largely observed Felt indoors by many people, outdoors by very few. A few
people are awakened. Windows, doors and dishes rattle.
V Strong Felt indoors by most, outdoors by few. Many sleeping people
awake. A few are frightened. Buildings tremble throughout.
Hanging objects swing considerably. Small objects are
shifted. Doors and windows swing open or shut.
VI Slightly damaging Many people are frightened and run outdoors. Some objects
fall. Many houses suffer slight non-structural damage like
hair-line cracks and fall of small pieces of plaster.
VII Damaging Most people are frightened and run outdoors. Furniture is
shifted and objects fall from shelves in large numbers. Many
well built ordinary buildings suffer moderate damage: small
cracks in walls, fall of plaster, parts of chimneys fall down;
older buildings can show large cracks in walls and failure of
fill-in walls.
VIII Heavily damaging Many people find it difficult to stand. Many houses have large
cracks in walls. A few well built ordinary buildings show
serious failure of walls, while weak older structures can
collapse.
IX Destructive General panic. Many weak constructions collapse. Even well
built ordinary buildings show very heavy damage: serious
failure of walls and partial structural failure.
X Very destructive Many ordinary well built buildings collapse.
XI Devastating Most ordinary well built buildings collapse, even some with
good earthquake resistant design are destroyed.
XII Completely devastating Almost all buildings are destroyed.

5.3 Example of magnitude scale
The Moment Magnitude Scale (MMS; denoted explicitly by M ) is a measure of an earthquake’s
w
magnitude, size or strength, based on its seismic moment, which is a measure of the work done
by the earthquake. The Moment Magnitude Scale (M ) is considered the authoritative
w
magnitude scale for ranking earthquakes by size. Caltech seismologist Hiroo Kanamori [3] using
an approximate relation between radiated energy and seismic moment approximated M by
w
M = (log M − 9,045)/1,5
w o
where
M = seismic moment is a measure of the work accomplished by the faulting of an earthquake;
o
it is measured in the units of newton metres (Nm) or joules.
An approximate indication of the relationship between seismic moment and the Moment
Magnitude Scale is given in Table 3.

– 10 – IEC 60721-2-6:2022 © IEC 2022
Table 3 – Moment Magnitude Scale
M M
w o
J
1,11 × 10
3,51 × 10
1,11 × 10
3,51 × 10
1,11 × 10
3,51 × 10
1,11 × 10
3,51 × 10
1,11 × 10
3,51 × 10
1,11 × 10
6 Description of the seismic environment by response spectra
6.1 Response spectrum
A commonly accepted design description of the seismic environment specially for testing
purposes is the use of response spectra. In a response spectrum the maximum absolute value
of the time history response (displacement, velocity or acceleration) of a family of oscillators,
each having a single degree of freedom with fixed viscous damping ratio, is plotted versus the
undamped natural frequency of these oscillators when subjected to the base movement caused
by the earthquake. It can be noted that a response spectrum is not an analytic function and it
should not be confused with a spectrum. See ISO 2041 and ISO 18431-4 [4].
In Figure 1 an example of an acceleration record (natural time history) of a real earthquake is
given. The ground acceleration was recorded during the Irpinia-Basilicata-Italy 1980 earthquake
in Calitri village; the moment magnitude scale M = 6,8 and the EMS-98 intensity = 8.
w
Figure 2 shows a model for composing a response spectrum. The time domain response to the
base vibration amplitude of oscillators with natural frequencies f (i = 1 to n) and constant
ri
damping ratio is registered and the absolute maximum value is picked for each oscillator and
plotted against its natural frequency. The response amplitude of an oscillator will be all the
greater the longer and stronger it is excited at its damped natural frequency.
6.2 Ground response spectrum
If a ground motion time history has been recorded at the site of an earthquake, or near it, this
is used to establish a shock response spectrum (SRS) (Figure 3).
A representative number of ground response spectra determined from different earthquakes is
used to describe the anticipated seismic stress for the site or area.

6.3 Required response spectrum
A dominating curve above the ground response spectra is termed a required response spectrum
because it marks the limits of the seismic ground motion at a given site or area during
earthquakes. This spectrum (Figure 4) gives the amplitude response (displacement, velocity or
acceleration) versus the natural frequency and damping ratio of the oscillators excited by the
ground motion.
Different mounting configurations of products at a certain site can lead to the use of different
corrected required response spectra according to the behaviour of their support (building
structure, floor, or enclosure, etc.), (see IEC 60068-3-3). For testing purposes it is common
practice to make reference to the ground acceleration response spectrum from which to derive
the test required response spectrum accommodating the earthquake excitation to the specific
mounting conditions. This test required response spectrum gives the limits of the seismic
excitation to which the product should be exposed to verify its capability to withstand the
earthquake (see ETSI EN 300 019-1-3 [5]).
7 Seismic activity zone classification
In order to define a local seismic ground motion it would be necessary to measure some local
seismograms from which to derive:
– the earthquake duration, and
– the response spectrum giving the distribution of the ground acceleration in the frequency
domain and the zero period acceleration, that is the peak ground acceleration (PGA).
Moreover, a statistical study should be performed with regard to the repetition rate of the
earthquake versus its intensity. Generally, a probable maximum intensity with probability
exceeding 10 % in 50 years, equivalent to a "return period" of 475 years, is used.
Earthquake zonation maps are reported in national and international standards and in natural
hazards studies made by insurance companies and research institutions [6], [7]. See also only
for information Annex A.
The following Table 4 gives a limited number of classes of seismic activity zones, covering the
whole range of possible values of the peak ground acceleration.
Table 4 – Seismic activity zones
Seismic
Peak ground acceleration (PGA)
activity zone
m/s
0 0,01 to 0,2
1 0,2 to 0,5
2 0,5 to 1
3 1 to 2
4 from 2 to more than 20
The user of this document should select the lowest classification necessary for covering the
conditions of seismicity of the intended zone of installation.
The identification of the peak ground seismic acceleration of the zone where the equipment
could be installed, can be subject to relevant national standards and laws.

– 12 – IEC 60721-2-6:2022 © IEC 2022

Figure 1 – Acceleration record of the Irpinia-Basilicata-Italy earthquake (1980)

Key
a base acceleration amplitude f natural frequency
A k
response acceleration amplitude stiffness
a i
D damping M mass
i i
f natural frequency of distinct oscillators t time
ri
Figure 2 – Model for composing a response spectrum

– 14 – IEC 60721-2-6:2022 © IEC 2022

Figure 3 – Response spectrum of the Calitri record of Irpinia earthquake (1980)
(Figure 1) for 2 % damping ratio value

Key
A response acceleration amplitude
a
A response displacement amplitude
s
response velocity amplitude
A
v
f natural frequency
r
D damping ratio
Figure 4 – Example of required response spectrum for ground motion

– 16 – IEC 60721-2-6:2022 © IEC 2022
Annex A
(informative)
Example of seismic activity zones
A.1 Classification criteria of US Uniform Building Code
The UBC seismic provisions contain six seismic zones, ranging from 0 (no chance of severe
ground shaking) to 4 (chance of the most severe ground shaking). The correspondence between
the seismic zone and a peak ground acceleration (10 % chance of occurrence in a 50-year
interval) is depicted in the following Table A.1. See [6].
Table A.1 – Seismic activity zones definition according to UBC
Seismic activity
Peak ground acceleration (PGA)
zone
m/s
0,0 to 0,5
1 0,5 to 0,75
2A 0,75 to 1,5
2B 1,5 to 2
3 2 to 3
4 from 3 to more than 4
A.2 World seismic activity zones classification according to UBC
In the following Table A.2 a list of the world seismic activity zones is reported following the
classification rules of the US Uniform Building Code (UBC).
Table A.2 – Seismic activity zones classification according to UBC
Seismic
Country/City
zone
Afghanistan – Kabul 4
Albania – Tirana 3
Algeria – Algiers 3
Algeria – Oran 3
Angola – Luanda 0
Argentina – Buenos Aires 0
Australia – Brisbane 1
Australia – Canberra 1
Australia – Melbourne 1
Australia – Perth 1
Australia – Sydney 1
Austria – Salzburg 2A
Austria – Vienna 2A
Azores – All 2A
Bahamas Islands – All 1
Seismic
Country/City
zone
Bahrain – Manama 0
Bangladesh – Dacca 3
Belgium – Antwerp 1
Belgium – Brussels 2A
Belize – Belmopan 2A
Benin – Cotonou 0
Bermuda – All 1
Bolivia – La Paz 3
Bolivia – Santa Cruz 1
Botswana – Gaborone 0
Brazil – Belem 0
Brazil – Belo Horizonte 0
Brazil – Brasilia 0
Brazil – Manaus 0
Brazil – Porto Alegre 0
Brazil – Recife 0
Brazil – Rio de Janeiro 0
Brazil – Salvador 0
Brazil – Sao Paulo 1
Brunei – Bandar Seri Begawan 1
Bulgaria – Sofia 3
Burkina Faso – Ouagadougou 0
Burma – Mandalay 3
Burma – Rangoon (Myanmar – Yangon) 3
Burundi – Bujumbura 3
Cameroon – Douala 0
Cameroon – Yaounde 0
Canada – Argentia NAS 2A
Canada – Calgary 1
Canada – Churchill 0
Canada – Cold Lake 1
Canada – E. Harmon AFB 2A
Canada – Edmonton 1
Canada – Fort Williams 0
Canada – Frobisher 0
Canada – Goose Airport 1
Canada – Halifax 1
Canada – Montreal 3
Canada – Ottawa 2A
Canada – St. John's 3
Canada – Toronto 1
Canada – Vancouver 3
Canada – Winnipeg 1
– 18 – IEC 60721-2-6:2022 © IEC 2022
Seismic
Country/City
zone
Canal Zone – All 2A
Cape Verde – Praia 0
Caroline Is. – Koror, Palau Is. 2A
Caroline Is. – Ponape 0
Central African Republic – Bangui 0
Chad – Ndjamena 0
Chile – Santiago 4
Chile – Valparaiso 4
China – Beijing 4
China – Chengdu 3
China – Guangzhou 2A
China – Nanjing 2A
China – Shanghai 3
China – Shenyang 2A
China – Taiwan (All) 4
China – Urumqi 4
China – Wuhan 2A
China – Hong Kong 2A
Colombia – Bogota 3
Congo – Brazzaville 0
Costa Rica – San Jose 3
Croatia – Zagreb 3
Cuba – All 2A
Cyprus – Nicosia 3
Czech Republic – Prague 1
Denmark – Copenhagen 1
Djibouti – Djibouti 3
Dominican Republic – Santo Domingo 3
Ecuador – Guayaquil 3
Ecuador – Quito 4
Egypt – Alexandria 2A
Egypt – Cairo 2A
Egypt – Port Said 2A
El Salvador – San Salvador 4
Equatorial Guinea – Malabo 0
Eritrea – Asmara 3
Ethiopia – Addis Ababa 3
Fiji – Suva 3
Finland – Helsinki 1
France – Bordeaux 2A
France – Lyon 1
France – Marseille 3
France – Nice 3
Seismic
Country/City
zone
France – Paris 0
France – Strasbourg 2A
French West Indies – Martinique 3
Gabon – Libreville 0
Gambia – Banjul 0
Germany – Berlin 0
Germany – Bonn 2A
Germany – Bremen 0
Germany – Düsseldorf 1
Germany – Frankfurt 2A
Germany – Hamburg 0
Germany – Munich 1
Germany – Stuttgart 2A
Germany – Vaihingen 2A
Ghana – Accra 3
Greece – Athens 3
Greece – Kavalla 4
Greece – Makri 4
Greece – Rhodes 3
Greece – Souda Bay 4
Greece – Thessaloniki 4
Greenland – All 1
Grenada – Saint Georges 3
Guatemala – Guatemala 4
Guinea-Bissau – Bissau 1
Guinea – Conakry 0
Haiti – Port au Prince 3
Honduras – Tegucigalpa 3
Hungary – Budapest 2A
Iceland – Keflavik 3
Iceland – Reykjavik 4
India – Mumbai (Bombay) 3
India – Calcutta 2A
India – Madras 1
India – New Delhi 3
Indonesia – Bandung 4
Indonesia – Jakarta 4
Indonesia – Medan 3
Indonesia – Surabaya 4
Iran – Isfahan 3
Iran – Shiraz 3
Iran – Tabriz 4
Iran – Tehran 4
– 20 – IEC 60721-2-6:2022 © IEC 2022
Seismic
Country/City
zone
Iraq – Baghdad 3
Iraq – Basra 1
Ireland – Dublin 0
Israel – Haifa 3
Israel – Jerusalem 3
Israel – Tel Aviv 3
Italy – Aviano AFB 3
Italy – Brindisi 0
Italy – Florence 3
Italy – Genoa 3
Italy – Milan 2A
Italy – Naples 3
Italy – Palermo 3
Italy – Rome 2A
Italy – Sicily 3
Italy – Trieste 3
Italy – Turin 2A
Ivory Coast – Abidjan 0
Jamaica – Kingston 3
Japan – Fukuoka 3
Japan – Itazuke AFB 3
Japan – Misawa AFB 3
Japan – Naha, Okinawa 4
Japan – Osaka/Kobe 4
Japan – Sapporo 3
Japan – Tokyo 4
Japan – Wakayama 3
Japan – Yokohama 4
Japan – Yokota 4
Johnson Island – All 1
Jordan – Amman 3
Kenya – Nairobi 2A
Korea – Kimhae 1
Korea – Kwangju 1
Korea – Pusan 1
Korea – Seoul 0
Kuwait – Kuwait 1
Laos – Vientiane 1
Lebanon – Beirut 3
Leeward Islands – All 3
Lesotho – Maseru 2A
Liberia – Monrovia 1
Libya – Tripoli 2A
Seismic
Country/City
zone
Libya – Wheelus AFB 2A
Luxembourg – Luxembourg 1
Malagasy Republic
(Madagascar) – Tananarive
Malawi – Blantyre 3
Malawi – Lilongwe 3
Malawi – Zomba 3
Malaysia – Kuala Lumpur 1
Mali – Bamako 0
Malta – La Valletta 2A
Mariana Islands – Guam 3
Mariana Islands – Saipan 3
Mariana Islands – Tinian 3
Marshall Islands – All 1
Mauritania – Nouakchott 0
Mauritius – Port Louis 0
Mexico – Ciudad Juarez 2A
Mexico – Guadalajara 3
Mexico – Hermosillo 3
Mexico – Matamoros 0
Mexico – Mazatlan 2A
Mexico – Merida 0
Mexico – Mexico City 3
Mexico – Monterrey 0
Mexico – Nuevo Laredo 0
Mexico – Tijuana 3
Morocco – Casablanca 2A
Morocco – Kenitra (Port Lyautey) 1
Morocco – Rabat 2A
Morocco – Tangier 1
Mozambique – Maputo 2A
Nepal – Kathmandu 4
Netherlands – All 0
New Zealand – Auckland 3
New Zealand – Wellington 4
Nicaragua – Managua 4
Niger – Niamey 0
Nigeria – Ibadan 0
Nigeria – Kaduna 0
Nigeria – Lagos 0
Norway – Oslo 2A
Oman – Muscat 2A
Pakistan – Islamabad 4
Pakistan – Karachi 4
– 22 – IEC 60721-2-6:2022 © IEC 2022
Seismic
Country/City
zone
Pakistan – Lahore 2A
Pakistan – Peshawar 4
Panama – Colon 3
Panama – Galeta 2B
Panama – Panama 3
Papua New Guinea – Port Moresby 3
Paraguay – Asuncion 0
Peru – Lima 4
Peru – Piura 4
Philippine Is. – Baguio 3
Philippine Is. – Cebu 4
Philippine Is. – Manila 4
Poland – Krakow 2A
Poland – Poznan 1
Poland – Warszawa 1
Portugal – Lisbon 4
Portugal – Porto 3
Qatar – Doha 0
Republic of Rwanda – Kigali 3
Romania – Bucharest 3
Russia – Moscow 0
Russia – St. Petersburg 0
Samoa – All 3
Saudi Arabia – Al Batin 1
Saudi Arabia – Dhahran 1
Saudi Arabia – Jeddah 2A
Saudi Arabia – Khamis Mushayt 1
Saudi Arabia – Riyadh 0
Senegal – Dakar 0
Seychelles – Victoria 0
Serbia – Belgrade 2A
Sierra Leone – Freetown 0
Singapore – All 1
Slovakia – Bratislava 2A
Somalia – Mogadishu 0
South Africa – Cape Town 3
South Africa – Durban 2A
South Africa – Johannesburg 2A
South Africa – Natal 1
South Africa – Pretoria 2A
Spain – Barcelona 2A
Spain – Bilbao 2A
Spain – Madrid 0
Seismic
Country/City
zone
Spain – Rota 2A
Spain – Seville 2A
Sri Lanka – Colombo 0
Swaziland – Mbabane 2A
Sweden – Goteborg 2A
Sweden – Stockholm 1
Switzerland – Bern 2A
Switzerland – Geneva 1
Switzerland – Zurich 2A
Syria – Aleppo 3
Syria – Damascus 3
Tanzania – Dar es Salaam 2 A
Tanzania – Zanzibar 2A
Thailand – Bangkok 1
Thailand – Chiang Mai 2A
Thailand – Songkhla 0
Thailand – Udon 1
Togo – Lome 1
Trinidad & Tobago – All 3
Tunisia – Tunis 3
Turkey – Adana 2A
Turkey – Ankara 2A
Turkey – Izmir 4
Turkey – Istanbul 4
Turkey – Karamursel 3
Uganda – Kampala 2A
Ukraine – Kiev 0
United Arab Emirates – Abu Dhabi 0
United Arab Emirates – Dubai 0
United Kingdom – Belfast 0
United Kingdom – Edinburgh 1
United Kingdom – Edzell 1
United Kingdom – Glasgow/Renfrew 1
United Kingdom – Hamilton 1
United Kingdom – Liverpool 1
United Kingdom – London 2A
United Kingdom – Londonderry 1
United Kingdom – Thurso 1
Uruguay – Montevideo 0
Venezuela – Caracas 4
Venezuela – Maracaibo 2A
Vietnam – Ho Chi Minh (Saigon) 0
Wake Island – All 0
– 24 – IEC 60721-2-6:2022 © IEC 2022
Seismic
Country/City
zone
Yemen – Aden 3
Yemen – Sanaa 3
Zaire – Bukavu 3
Zaire – Kinshasa 0
Zaire – Lubumbashi 2A
Zambia – Lusaka 2A
Zimbabwe – Harare (Salisbury) 3

Bibliography
[1] IEC 60721-1, Classification of environmental conditions – Part 1: Environmental
parameters and their severities
[2] European Macroseismic Scale 1998 (EMS 98) – Editor G. GRÜNTHAL – CONSEIL DE
L’EUROPE – Cahiers du Centre Européen de Géodynamique et de Séismologie –
Luxembourg 1998
[3] Hanks, T. C., and H. Kanamori (1979). A moment magnitude scale, Journal of
Geophysical Research, 84, 5, 2348 – 2350, 9B0059, doi:10.1029/JB084iB05p02348
[4] ISO 18431-4, Mechanical Vibration and Shock – Signal processing – Part 4: Shock-
response spectrum analysis
[5] ETSI EN 300 019-1-3 v2.3.2 (2009-11) – Environmental Engineering (EE);
Environmental conditions and environmental tests for telecommunications equipment;
Part 1-3: Classification of environmental conditions; Stationary use at weatherprotected
locations
[6] SCAFCO Grain Systems Co., available at http://scafcograin.com/language/en/
[7] M. Pagani, J. Garcia-Pelaez, R. Gee, K. Johnson, V. Poggi, R. Styron, G. Weatherill, M.
Simionato, D. Viganò, L. Danciu, D. Monelli (2018). Global Earthquake Model (GEM)
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