Elenco Glossario (versione inglese)

In general terms, it is the conditions of safety, hygiene, health and energy efficiency of buildings and facilities, evaluated on the basis of existing legislation. In seismic emergency, following an event, the "judgement of conformity" issued by the technicians who work during the emergency, is the possibility to continue using the building for functions that was used, reasonably protecting human life in case of a new tremor of intensity comparable to that already happened. In order to give the opinion of usability, engineers are engaged in the relief of the damage. The result has validity up to a shock later that significantly modifies the resistance of the building or until the ix of the building is complete, after which a technician prepares a final report on the practicability of the same building.

Parametre describing basic dangerousness for reference seismic action on ordinary works (Class II of Building Techinical Regulations). 

Document issued by the peripheral Functional, when it gets activated and is autonomous in regard to weather forecasts, in case of events of recognized importance on a regional scale.

Areas to be used for civil protection in the event of an emergency. These may be one of three types:
- Assembly areas for relief operators and resources
- Waiting areas for the population
- Sheltered areas for the population

It is a mineral common in nature and due to its resistance to fire, heat and the action of chemical and biological agents it has been used for many purposes (in industry, building, etc.). However, since 1992 in Italy its use has been forbidden as it represents a potential hazard due to the dispersal of particles into the environment that when inhaled caused very serious diseases in man.

Document issued by the Civil Protection Department in the case of several regional weather alerts and/or weather events of importance beyond the regional scale.
The national weather warning is therefore the integration of regional weather alerts and assessments carried out by the Department in relation to the same regions whenever the relevant peripheral Functional Centre(s) has not yet been activated or is not autonomous regarding weather forecasts.

Document issued by the peripheral Functional Centre (when activated) or the central Functional Centre (based on the principle of subsidiarity) describing a general evaluation of ongoing events with moderate or high criticality level. The notice shows the type of risk and criticality level expected for at least the following 24 hours in each alert zone. The competence of the notice is of the President of the Regional Council or the delegated body - as provided for by the relevant regional regulations. 

Document issued, depending on the competences, by the DPC or by the Regions to call attention to possible additional and specific events reported in the Bulletins Monitoring weather and/or criticalities. May relate to events already planned as particularly unusual or critical, or events in a manner not expected, but with time consistent with the scope and effectiveness of monitoring and verification of instrumental effects on the land, they evolve towards higher levels of criticality.
The document is made ??available to the National Service of Civil Protection, so that, on the basis of procedures uniquely and individually developed and adopted by the regions, are activated different alert levels that correspond to appropriate preventive measures and emergency management.


Relating to man and his activities. The word comes from the Greek “anthropos” meaning man.

Activities aimed at checking the readiness and efficiency of the operating units and components of civil protection, through simultion exercises, verification of civil protection plans and, in general, practical verification of procedures to be followed in emergencies. (art. 6-11, L. 225/1992).

Places for the installation of emergency dwelling areas with sufficient dimensions to accommodate at least one tent city for 500 people and field services. They are located close to water and electricity supplies, equipped with a waste water drainage system, and in areas not subject to risks of flooding, landslides, collapse of rocky masses, etc. The areas must be near a road junction or in any case easily reached, and the route must be marked on the map.

Emergency reception areas for the population, which may be located in squares, open spaces, car parks, public or privates areas deemed suitable and not subject to risks – landslides, flooding, collapse – accessible by way of a safe route, possibly pedestrian, which is marked on the map. In these areas, the population receives basic information on the event as well as emergency comfort and support, as they wait for the sheltered areas to be set up.

Places in which the rational deployment of relief operators and resources in the intervention areas is guaranteed. They are located in safe areas in terms of risk of landslides, collapse and flooding, near water and electricity supply systems as well as waste water networks, and can be reached by way of safe routes, even with large vehicles. The Mayor of a municipality in which a MOC, Mixed Operations Centre, is set up, must identify at least one assembly area and mark the best route to gain access to it on the map. Relief for Municipalities served by the MOC depart from these areas.

Phenomenon linked to fermenting processes that lead to a production of heat and gas, which, when exposed to oxygen, may become a point of ignition and start a fire. Spontaneous combustion hardly occurs in woods.

Device composed by seismometers or geophones following a specific geometry, that collects data in syncronous way within a central unit.   

A method of studying the subsoil based on artificial generation of seismic waves – e.g. sledge hammer, explosions – and measurement of the arrival times of the waves at a series of receptors (geophones) positioned in a line. The waves used are those subject to refraction phenomena along the surface of passage between means that increase in density with depth. This kind of analysis is very useful for defining the thickness of “soft” surface soils.

A method of examining the subsoil based on analysis of ambient seismic noise (micro tremors), small amplitude seismic waves caused by natural or man-made sources such as the waves in the sea, the wind, traffic, etc. By measuring the frequency of ground vibration, this analysis determines the thickness of “soft” surface soils, when the propagation velocity of shear waves Vs or the thickness of the surface is known. In both cases, measurement of micro-tremors permits subsoil geological model reconstruction used in seismic microzonation studies.

Modification in amplitude, frequency and duration of seismic shaking due to the specific lithostratigraphic and morphological conditions of a site. This can be quantified by calculating the ratio of the seismic motion on the site surface to that observed for the same seismic event on a hypothetical rigid rock outcrop with horizontal morphology. Any ratio greater than 1 is local amplification.

Secondary tremors that come after the main tremor in a seismic series. The number of secondary tremors is usually directly proportional to the size of the main tremor. The tremors are less violent than the main event and the hypocentres concentrated in a limited area of the earth’s crust surrounding the hypocentre dof the main event.

Transformed or adapted environment either to meet the needs of humans, or by human activity.

Unlike laboratory tests, the geognostic analysis can be performed directly on the site of investigation, eg. penetration tests, geophysical tests.

Bulletin issued by the Central Functional Centre to report significant weather events planned for the day of issuance and for the following days, on each one of the supervisions areas in which the Italian territory is divided.

The document represents which are the meteorological phenomena relevant for civil protection purposes and how many.

Bulletin issued by the Central Functional Centre to report the assessment of levels of hydrogeological and hydraulic criticality, expected on average for the following 36 hours from the time of issuance, in the alert areas that comprise the Italian territory.

The document is the evaluation of the possibility, or evolution, to ground effects (landslides and floods) due to meteorological factorsd, based on predefined event scenarios. The prediction is therefore to be understood in a probabilistic way, such as degree of probability of the occurrence of predefined risk scenarios in an area of the order of at least a few tens of kilometers.

Pyroclastic fragment measuring over 64 mm, emitted in a liquid or semi-liquid state that then solidifies during its flight through the air or as it hits the ground.

Set of interventions that aim to eliminate sources of pollution and pollutants, or reduce the concentrations in the soil, subsoil and groundwater to a level equal to or less than the CSR -threshold concentration of risk.



Fragment measuring over 64 mm, emitted in a solid state and deriving from the vent of the volcanic building (not magmatic).

A document issued daily by the Central or Peripheral Functional Centre, which shows a forecast of expected events, both in terms of weather and in terms of assessing possible consequent effects on the territory.
The forecast is to be understood in a probabilistic way, associated with significant levels of uncertainty and that persists for some types of phenomena, eg. time.

The document is made ??available to the National Civil Protection Service, so that, on the basis of procedures uniquely and individually developed and adopted by the regions, different alert levels get activated, corresponding to appropriate preventive measures and emergency management.

It is the property of organic substances and of some synthetic substances to decompose in nature (thanks to several bacteria). This allows regular maintenance of the planet’s ecological equilibrium.

Set of guarantees recognised to civil protection as provided for the President of the Republic's decree no. 194 of 8 February 2001.

Workers who are also volunteers have the right of stay away from work for activities authorized by the Civil Protection Department or local authorities of civil protection - that have adopted their own statutory tools as provided for by art. 15 of Dpr 194/200: they have the right to receive their salary during their absence and cannot be fired from their workplace.

The employer is bound to allow the carryng out of the activities and has the right of asking to the Civil Protection or the local relevant authority -  where possible -the reimbursement of monies paid to the worker following the preliminary path indicated.

Lithostratigraphic sequence characterised by a shear wave velocity Vs of 800 m/s or more.

Compact, rigid, unaltered rock, either an outcrop or the base of less rigid rocks/soils or of loose sediment. A term commonly used by geologists to refer to any diagenised rock/consolidated soil that has not undergone the meteoric processes of alteration and deterioration or pervasive tectonic deformation.

Unit through which the Department of Civil Protection coordinates the activity of extinguishing forest fires with the State air fleet on national territory. The COAU receives requests for intervention forwarded by the COR or SOUP. Any part of the country can be reached within 60-90 minutes of take off. The COAU is an operating service of Department VIII – Air activities of the Department of Civil Protection.

Civil Protection Department Operations Centre – Emergency management office that works in normal and emergency situations as part of the System.
It contributes to the management of crises caused by sea pollution and supports decontamination and salvage of flotsam and jetsam at sea or on the shore, if a state of emergency is declared. It also monitors aid provided for accidents at sea and activates marine units used for Civil Protection purposes.

Central body of the National civil protection service that ensures unified management and coordination of emergency activities, setting out the interventions of all the administrations and organisations involved in providing relief.

The central administration of the State, regions, provinces, municipalities and mountain communities which, according to the respective legislation and competences, see that civil protection activities are put into action. Also contributing to civil protections activities are public sector agencies, institutions and scientific research groups, all other institutions and organisations including private ones, citizens, voluntary groups and professional associations.

The top coordination body for civil protection activities during an emergency on a provincial level, comprising the heads of all the operating units working in the province. The Ccs identify strategies and measures for dealing with emergencies, also through coordination of activities by the Moc - Mixed operation centres. They are organised into support functions.

Operating unit that coordinates emergency services.
The Com must be located in anti-seismic buildings in compliance with the current legislation, and not exposed to any kind of risk. The facilities used as Coms must have a minimum total surface area of 500 m2 with an internal division that entails at least: a room for meetings, a room for support functions, a room for volunteers, and a room for telecommunications.

Operations centre in support of the Mayor, for the management and coordination of relief and assistance services to the population. The centre must be located in anti-seismic buildings, inside areas that are easily accessed and not exposed to any kind of risk.

Network of support centres to the decisions of the competent authorities for alerts and emergency management.
For the purposes of the functions and tasks of evaluation, decision-making, and the consequent acceptance of responsibility, the network of functional consists of the Regional Functional Centres, or decentralized and a State or Central Functional Centre, Department of Civil Protection.

The network of Functional Centres operates according to shared criteria, methods, standards and procedures and is a part of the National Civil Protection Service. The service provided by the network, under the management of the national warning system for hydraulic and hydrogeological risk, is divided into two phases: the prediction of the nature and intensity of weather events expected, of the impact of such events that could occur in the area, the evaluation of the level expected in critical areas and the surveillance and monitoring phase of the territory.

Flow of magma emitted during an effusive volcanic eruption.

Structure that deals with crisis situations linked to the road system by adopting, even as a prevention, the most suitable intervention strategies . The centre is established by the Ministry of Interiors, that participates into it with his representatives - Fire Department, public air and civil defence and Department for internal and territorial affairs -, along with the ones of the Ministry of Infrastructures and Transportation, the Civil Protection Department, Carabinieri, Anas (National Autonomous Roads Corporation), Aiscat (National Association of Dealer Society for motorways and tunnels), and National Railways.

Operations centre activated in some particular situations. It is competent for specific sectors of intervention in a limited area.

Headquarters of the Chief of the Defence Staff, which contributes to general Defence Planning, carries out operational planning and directs joint-force operations and drills. It develops the methods for the simulation of strategic and operational scenarios, analyses activities and contributes to the formulation of doctrine for NATO and other international organisations

A map that identifies the zones where, based on lithostratigraphic and geomorphologic characteristics, it is possible to forecast homogeneous behaviour in the event of an earthquake. On the map, the microzones are divided into:

a) stable zones, where no significant local effects are hypothesised and seismic motion is not modified
b) stable ones susceptible to local amplification, where amplifications of seismic motion are expected
c) zones susceptible to instability, where the expected predominant seismic effects can be traced back to permanent deformation of the territory. The main kinds of instability are:

- landslides
- liquefaction
- active and capable faults
- differential compaction


Civil protection centre set up in the area hit by the emergency to guarantee coordinate management of intervention. The centre must be located in an area safe from the various kinds of risks, in premises that are suitable from a structural, functional and logistics point of view. It is divided into support functions, according to the Augustus Method, with all the administrations, bodies and individuals that work together in management of the emergency represented. The classic coordination chain, a purely theoretic model, sees from a local to national level activation of the following Centres in hierarchical order: Coc - Centro operativo comunale (municipal operations centre), Com - Centro operativo misto (mixed operations centre), Ccs, - Centro coordinamento soccorsi (relief coordination centre), Dicomac - Direzione comando e controllo (command and control headquarters).

Level 3 seismic microzonation maps associate a numerical quantification of seismic motion amplification to the zones or parts of zones identified on the Map of homogeneous microzones from a seismic perspective. These numerical quantifications permit the following maps to be drawn up:

- map of stable zones and stable zones susceptible to local amplification, characterised by amplification factors;
- map of zones with permanent deformation, characterised by quantity parameters.
Overlapping these two maps gives a level 3 seismic microzonation map.

A mixture of pyroclastics, gas and steam emitted during an explosive eruption. It rises in the atmosphere at great speed and can reach heights vary according to the energy of the eruption and the size and shape of the duct.

Fast-moving current of superheated gas (which can reach temperatures of about 1,000 °C (1,830 °F)) and rock. They are a common and devastating result of certain explosive volcanic eruptions. The flows normally hug the ground and travel downhill, or spread laterally under gravity. Their speed depends upon the density of the current, the volcanic output rate, and the gradient of the slope. Their distribution may vary, depending on the morphology of the area.


Wide subcircular depression created by a volcano, generally measuring more than a kilometre in diameter. It has subvertical walls and is the result of the collapse of a small or large part of the roof of a near-surface magmatic chamber that emptied following a big eruption.

Structure through which the magma rises to the surface.

Chamber where magma accumulates, located a few kilometres below the volcano. 

Sequence of device, functional and/or structural, that allows the management of disaster victims. It deals with the identificatio, delimitation and coordination of different intervention sectors for victims rescue, the Rescue Noria set-up between the event place and the Pma, and the Evacuation Noria set-up between the Pma and hospitals.

It is like a normal aid chain, but more complex due to the event or for environmental features. It usually features one or more evacuation health centres (Cme), along the la evacuation noria. Field hospitals, le navi ospedale, mobile surgery medical units are equivalent to Cme's.

Common Emergency Communication and Information Centre.

It facilitates communication between the MIC with National Authorities. Its main task is to host a database on potentially available assets for assistance, to handle requests for assistance on the basis of these data, to exchange information and to document all action and message traffic through the European Civil Protection Mechanism.


Collegial body with consulting capacity. It is composed of one representative from each volunteer organization of civil protection at national level which is listed in the National Civil Protection Department.

The council was set up by decree of the President of the Council of Ministers of 25 January 2008 at the Civil Protection Department.

Operations centre that coordinates emergency intervention in an area that generally covers more than one neighbouring municipality or corresponds to the territory of competence of the mountain communities. In many territorial situations, the COI is not activated only in emergencies but also works in normal situations and acts as a local point of reference and contact for civil protection activity.

Financial aid that may be granted in emergencies, with a special order, to citizens who, forced to leave their homes, are willing to provide independently for their own accommodation arrangements.

Structural device for the sanitary treatment of victims; it is activated in case of catastrophes on wide areas. It is located along the path of the Evacuation Noria to allow  permettere di stabilizzare il trattamento dei feriti ed ottimizzare, su più ampia scala, l'utilizzazione delle risorse di trasporto sanitario e quelle di cura definitiva. Ad uno stesso Cme possono afferire più Pma. È sinonimo di ospedale da campo.

Fertilister used in farming and gardening to add to the soil one or more nutritious elements that can be used by plants.

It is the result of decomposition and humification of a mixture of organic materials (like for example pruning waste, leaves and grass clippings from the garden, kitchen waste, manure and sewage) by macro and microorganisms in particular conditions. It is a product obtained from the composting of the organic part of urban waste, respecting special technical standards that define content and use compatible with protecting the environment and health and in particular that define quality levels.

Tar belongs to the category of bituminous materials and is a composite deriving from the dry distillation of fossil carbon, in particular of bituminous coal (the most important fossil carbon). It is a thick black or dark brown liquid.

This is the well-balanced group of relief teams, means, equipment and specialist modules, even belonging to different but jointly coordinated structures, that intervene in emergency situations.
The mobile column is designed and created to guarantee instrumental and performance operative standards that are the same for all interventions and ensure the necessary continuity of action throughout the entire duration of the calamity.

Logistic pole where emergency resources are properly stored in order to be promptly used for aid and assistance to the population (tents, plant design, beds and sheets, generators, etc.) and rescuers efficiency (means, draining pumps, water purifyng devices, etc.).

Boards covering several volunteer organizations that get together and recognize a common statute. They can create a new organization self-registered regional or national, or may represent de facto coordination. They aim to strengthen relations between the various components of the volunteers, maintain links and collaborate with institutions.

Advisory bodies of civil protection voluntary work organizations at regional level. They are established with a regional measure and can be included in regional laws. The same advisory functions are carried out, at provincial level, by provincial voluntary work councils. 


Organisms with the purposes of supporting and qualifying activities of voluntary work organizations. They are provided by art. 15 of law no. 266 of 1991 on voluntary work and are established at local boards. They are financed with special regional funds. Voluntary work organization manages them and the applicants for the establishment request may be:: local boards, a minimum number of 5 voluntary work organizations, bank patronized fundations, and savings banks.

Presence of a radioactive substance in foodstuffs, materials, surfaces, home or work environments or in a human organism.

Refuse-derived fuel (RDF), following UNI 9903-1 technical laws Fuel Many fuels can be derived from waste, refuse can be combusted directly in an incinerator to provide power, methane produced at landfill can be collected and combusted, even chicken litter can be dried and combusted. However since this report is looking into biofuels for transport this section will concentrate only on liquid and gas fuels produced from waste that are suitable for combustion in a vehicle engine.


Combustibile classificabile come Rdf di qualità normale, sulla base delle norme tecniche UNI 9903-1 e successive modifiche e integrazioni. È recuperato dai rifiuti urbani speciali non pericolosi, mediante trattamenti finalizzati a garantire un potere calorifico adeguato al suo utilizzo, nonché a ridurre e controllare: il rischio ambientale e sanitario; la presenza di materiale metallico, vetri, inerti, materiale putrescibile e il contenuto di umidità; la presenza di sostanze pericolose, in particolare ai fini della combustione.

Technical structure established at Ispra with dlgs. no. 230/1995, activated in case of radiological events that represent a national emergency. For the evalutaion of the emergency, of environemental radioactivity levels and possible consequences, it operates supporting the Civil Protection Department, and the civil protection Operating Committee.

The structure established in 1992 has its premises in the General Inspectorate of the National Forestry Corps, to provide the necessary support and coordination to the national forestry operating activities. The whole activity of the Operating Centre is focused on the number 1515 for environmental emergencies. Calls received, along with the ones of the regional operating centres, are mainly about wood fires, reports of environmental damages, civil protection, public rescue and cruelty to animals.

Since 2000, each municipality is required to assess, through a special register, the stands already covered by fire in the previous five years, making use of surveys carried out by the State Forestry Corps, and update it annually in case of new fires.

The list of land areas hit by the fire and, therefore, subject to the limitations provided by law, must be exposed for thirty days to the town council, for comments.
After this deadline, the municipalities evaluate the comments submitted and approved within the next sixty days, the final lists and their perimeters. The revision of the lists with the deletion of provisions relating to the prohibitions referred to in paragraph 1 of art. 10 of Law 353/2000 is permitted, only when the periods indicated for each ban expiry.

A seismic survey that uses two or more borings (usually just a few metres apart). A vertical impulse source is placed into one and one or more receivers (geophones) into the others. Based on the distances that the waves travel, measurement of the times of the first arrival and/or amplitude of the elastic waves, the seismic wave speeds (Vs, Vp) can be calculated and the elastic parameters of the rock/ground determined. Depending on the method used, the results give either an integral average value for the zone under study or a seismic tomography of the soil.

The seismic classification is the division of the territory in zones with different seismic hazard. Italy is currently divided into four zones, where special technical regulations must be applied with growing levels of protection for building (anti-seismic standards), maximum in Zone 1, the most dangerous area, where severe earthquakes have caused very serious damage in the past. All Italian municipalities come under one of the four seismic zones.

Permanent deformations of varying entities of the foundation soils subject to seismic shaking. These manifest in the zones of contact between lithologies with different mechanical behaviour and can determine damage to buildings constructed on these soils.

A map showing the location and kind of surveys carried out to characterise the subsoil. As part of seismic microzonation studies, this map shows soundings, geophysical investigations, instrumental measurements and any other information used for characterising the territory from a seismic point of view.

Paper which sets out the limits of the lithological units recognized in the study area, distinguished on the basis of the physical characteristics of rocks and their age, or group of fossils. The paper also reports the non-active tectonic elements - faults, folds, thrust faults - and geomorphic.

Soil samples, commonly knows as "carrots", wihdrawn and kept in hollow punches, and used during laboratory tests for physical and mechanical soil characterization.

Sono le contabilità aperte, previa autorizzazione della Direzione generale del Tesoro, nelle Sezioni provinciali di Tesoreria nelle quali sono versati i fondi assegnati da Amministrazioni, Enti e organismi pubblici per assicurare una gestione separata di queste risorse.

The regional mobile Colums is created by a project of the Conference of Regions and Autonomous Provinces. It provides for functional modules interchangeable able to guarantee homogenous operating standards for every intervention and self-sufficiency for the entire emergency.

The mobile column is constituted by a complex of men, equipment and procedures and, in case of major interventions, is composed of:

• assistance modules to the population
• meal production and distribution modules
• emergency Telecommunication modules
• secretary and command module
• logistic module for operators and rescue activities
• health module – Advanced Medical Post (Pma)

Instantaneous and permanent deformations of the earth’s surface caused by earthquakes: lowering and raising of the soil, slope and fault scarp breaks.

The National coordination centre for the civil protection components and operating units, set up in the area in question when necessary by the Civil Protection Department in the event of a national emergency.

Doctor, or in his absence, a nurse in charge of coordinating triage operations for victims in the Pma. He related to the Director of sanitary aid.

Group of chemicals that are highly toxic and highly generally persistent in the environment and in biological systems. The generic term "dioxin" or "dioxins" is commonly used to describe a large family of chemicals that contain chlorine. These substances are characterized by similar properties, including difficulties in biodegrade, long duration in the environment, strong tendency to accumulate in living organisms.
They are a powerful carcinogen. Dioxins in the human body remain for several years.

Concept structure that aims at minimizing vulnerabilities to prevent or limit impact of disasters.
For the effectiveness of risk reduction, the prevention process needs to involve government bodies, the population, media, scientific components, and public and private sectors. 

Nurse or technical operator in charge of sanitary transportation, depending on the priorities of the triage operations. The director of transportation directly reports to the triage director.

Set of human and material resources used for the response to the event.

Organic compounds highly toxic and carcinogenic to humans.

This is the technological system that eliminates foreign or polluting substances from liquids and gases. The process comprises a series of programmed actions of a mechanical, physical and biological nature.

Where waste is deposited on a production site before being collected, at the following conditions:

1. The deposited waste must not contain polychlorodibenzodioxine, polychlorodibenzofuran, polychlorodibenzophenone in quantities exceeding 2.5 ppm or polychlorobiphenyl or polychlorotriphenyl in quantities exceeding 25 ppm;
2. The quantity of hazardous waste deposited must not exceed 10 m³, in other words the waste must be removed at least once every two months;
3. The quantity of non-hazardous waste deposited must not exceed 20 m³, in other words the waste must be removed at least once every three months;
4. The temporary deposit must be used for homogeneous kinds of waste and must respect the relative technical legislation. Hazardous waste must also respect legislation governing the deposit of the hazardous substances it contains.
5. The laws governing packaging and labelling of hazardous waste must be respected;
6. The Provincial Authorities must be informed of the temporary deposit of any hazardous waste.

Seismic survey carried out in a boring where a seismic source is placed on the surface close to the mouth of the hole and two or more receivers (geophones) are placed at preset depths inside the boring. The data obtained are the times it takes the shear and compression waves to travel from the source to the geophones. This method is normally used to determine shear and compression wave velocity at different depths, allowing reconstruction of the stratigraphy.

Data regarding the seismic and tectonic structure of a territory relative to seismicity – and energy of earthquakes – and to ratio with faults.

Data and information necessary for lithological and geotechnical characterisation of soils and rocks obtained through geognostic surveys and lab tests.

Point on the earth’s surface where the shaking caused by the passage of the seismic waves is strongest. The epicentre is vertical to the hypocentre.

Training activity for the national protection service components and operating units that, given a simulated scenario, check their procedures for alert, activation and intervention as part of the system for coordinating and managing the emergency.
These exercises may be held on an international, national, regional or local level and may actively involve the population.

It is the unit number (or “value”) of each of the elements at risk in a given area, like human lives or inhabited areas.

From Stromboli volcano, an eruption is characterized by bursts of low energy that are followed at regular intervals, from seconds to hours. The pieces of magma thrown up to several hundreds of meters high, fall to the ground and form a cinder cone.

Outpouring of magma through an eruptive mouth of a volcano. The eruption may be effusive, if the magma comes out in liquid form (called “lava”), or explosive, if the magma is fragmented into pieces of varying size (pyroclasts). Eruptions are classified according to their flow and the volume of magma emitted and the level of the blast.

Violent emission of fragmented magma driven by the gas it contains and/or as an effect of vaporisation of water from outside coming into contact with the magma.

Eruption during which magma is emitted in the form of lava flows.

Explosive eruption with phenomena similar to the ones of the plinian eruption, but with lower energy and consequent reduced distribution of eruptive mass.

Pliny the Younger described the eruption of Vesuvius in 79 AD, is an eruption characterized by explosions that produce eruptive columns that rise to tens of kilometers.
From the top of the column, less dense and pushed by winds aloft, falling particles that settle on no less than 500 km². The densest part of the column could collapse and produce pyroclastic flows.

Excessive water plant growth that occurs where there are large amounts of nutritious substances such as nitrogen, phosphorus or sulphur, deriving from natural or man-made sources - fertlizers, detergents, civil or industrial waste. Microscopic algae flourish and, since they cannot be completely digested by the ecosystem, cause a major baceria activity and lack of oxygen needed for fish to survive. Eutrophication is among causes of environmental decay.

This refers to electromagnetic pollution caused by electromagnetic radiations, radio broadcasters, electric wiring carrying current, networks for mobile phones and mobile phones themselves.

Effects due to the behaviour of the ground in the case of seismic events because of the presence of particular lito-stratigrafic and morphological conditions that determine local amplifications and ground instability phenomena (slope instability, liquefaction, active faults and capable faults, differential compaction, etc.).

Discharge from any solid, liquid or gas substance introduced into the ecosystem by any installation that may cause atmospheric pollution.


The whole made up of animal and plant organisms that interact with each other and with their surrounding environment: each element relates to the others.

Natural or manmade phenomenon capable of causing damage to the population, businesses, buildings and infrastructures, as well as the area. Law no. 225 of 1992, art. 2 identifies three types of civil protection event:

a) natural or man-related events that may be tackled with the ordinary intervention of a single organisation or authority;
b) natural or man-related events that, due to their nature and extent, require the coordinated, ordinary intervention of different organisations and authorities;
c) natural disasters, catastrophes or other events that, due to their intensity and extent, must be tackled using special means and powers.

Struttura che è responsabile dell’aiuto umanitario e delle operazioni di assistenza dell'Unione europea. Il suo compito principale è fornire assistenza alle vittime di catastrofi, contribuire a salvare e proteggere vite umane, ridurre le sofferenze e tutelare l'integrità e la dignità delle persone coinvolte. L'intervento di emergenza può comprendere la fornitura di tende, coperte e altri generi di prima necessità, quali cibo, medicinali, attrezzature mediche, sistemi di depurazione dell'acqua e combustibili. Finanzia inoltre squadre mediche, esperti in sminamento e fornisce sostegno nel campo dei trasporti e della logistica.

Point on the earth’s surface where the shaking caused by the passage of the seismic waves is strongest. The epicentre is vertical to the hypocentre.

The movement of the lithospheric plates ithat make up the earth’s crust causes great pressure on rocks deep down, leading to their breakage along fracture surfaces called faults. Rocks near the fault planes (the slip surface) are often intensely fragmented due to friction between the blocks of rock in relative motion. The fault may be:

- reverse, if the motion of the blocks of rock that touch along the break surface is compressive – the blocks overlap each other;
- normal or extensional faults, if the blocks move apart;
- strike-slip, if the motion of the blocks in mainly horizontal – the blocks slip sideways.


Natural emission of gaseous mixtures prevalently made up of water vapour. Dry fumaroles can reach a temperature of several hundred degrees centigrade. Whereas saturated steam fumaroles have a temperature close to the boiling point of water.

Variations in the physical and chemical parameters of a volcano system that indicate possible repeat eruptions. Some of these can only be detected by instruments, while others, such as for example more severe earthquakes, visible ground deformation, the appearance of the new fumaroles or the opening of fissures, can be recognised by people.

A structure that guides the magma towards the surface. The fissure may be caused by magma pressure, or may be a reactivated pre-existing structure. Volcanic activity may be distributed evenly right along the fissure, or more frequently, be concentrated in certain points, leading to alignment of volcanic buildings, typically cones.

They constitute the basic organisational structure of the operations centres and represent the different emergency management activity sectors. Each Function is made up of representatives from the units that cooperate, with professions and resources, in a specific sector, and whose coordination is entrusted to a person in charge. The support functions are activated in emergencies, in a flexible way, in relation to possible requirements and based on emergency planning.

A cloud denser than air made up of fragments of rocks and gas, characterised by high temperature and speed. It is generated by the collapse of an eruption plume supported either by a dome or by a lateral blast. It tends to flow to the ground under the force of gravity, to channel into valleys and fill depressions and some have enough energy to make their way over even tall morphological barriers. Their distribution in the area will therefore depend on morphology.

Fertilisers are technical means used in farming and gardening that create, reconstitute, preserve or increase soil fertility. Fertilisers are divided into the following categories, depending on how they improve the soil:

Soil feeders: these enrich the soil with one or more nutrition elements.
Soil improvers: these improve the physical properties of the soil, altering its structure and/or its fabric.
Soil correctors: they alter the reaction of anomalous soils, making the pH more neutral.

The structure belongs of the US Department of Homeland Security, Dhs – US Department of Homeland Securitysince 2003. It has the task of coordinating the Governement activities of preventing, mitigating, fighting disaster effects, both natural and man-made - including terrorist acts - and protecting, rescuing and granting safety measures for the population.

Phenomena that occur after an earthquake. Direct phenomena are permanent deformation of the topographic surface; indirect phenomena due to shaking and the entity of the shift on the fault plane are: landslides, ground splitting and liquefaction, variations in the flow of rivers, the generation of tsunamis.

Numerical parameter describing the amplification of the seismic motion in a given point compared with one measured in a reference site (bedrock), represented by hard (rock) or level ground. Amplification may be linked to the lithological and morphological features of the evaluated area. The amplification factor may be expressed in acceleration  (Fa) and/or speed (Fv) terms.

Active fault deemed capable of producing surface faulting, in other words instantaneous vertical and/or horizontal – coseismic – vdislocation of the ground along one or more shear planes.

A fault that shows signs of slipping between the two volumes of rock/ground in the past 40,000 years, leading to presume that they may slip some more.

Space-based global navigation satellite system that provides location information, based on signals sent by USA artificial satellites constellations  

Established at the Civil Protection Department, that coordinates it, is composed by a representative, respectively, of the Weather sector of the Central Functional Centre, of the Weather Service of the Air Force and of each Region whose weather services, or areas of weather forest of the respective Functional Centres, have been selected in regards to the level of competence, experience, operating and instrumental capabilities.

The Technical Group organized and formally communicates to the Head of Civil Protection Department by 12 p.m. each day weather forecasts on synoptic scale with civil protection purposes for the following 24, 48 and 72 hours - following the notices from authorized Functional Centres.

Collection, transport, recovery and disposal of waste, including checks made on these operations and checks on tips and disposal sites after their closure.

Event of particular organisational complexity in terms of safety, public order, mobility, reception and medical assistance, which requires the adoption of extraordinary and urgent measures, to ensure regular development of the event. Law no. 401 of 9 November 2001 extends the provisions of law no. 225 of 24 February 1992 on the declaration of a state of emergency to the “major event”, in particular on the use of ordinances signed by the Prime Minister.

Organization established by resoluntion of the local administration, that includes civil protection volunteers employed by the Mayor or one of his delegates.

Discipline of Earth Sciences that studies the shapes of the earth’s crust and the phenomena that modify it.

The volume of rock deep under the ground where the earthquake, originates and whence the seismic waves propagate in all directions.

Fire that hits interlink areas between urbanized and natural areas.

Unintentional event related to plant or other activities regarding radioactive substances. It may have different causes such as operating erros or equipment breakdown; consequences or potential consequences are not unimportant, both from a safety and radioprotection point of view. 


Ines - International Nuclear Event Scale is a tool that helps to enable prompt communication of safety significance information in case of nuclear accidents. Nuclear and radiological events are classified in 7 levels: major accident, serious accident, accident with wider consequences, accident with local consequences, serious incident, incident, anomaly. 

Institute that replaces and carries out all functions of ex-APAT, Italian Environment Protection and Technical Services Agency, ex-INFS, National Institute for Wildlife and ex-ICRAM, Central Institute for Scientific and Technological Research applied to the Sea. The Institute acts under the vigilance and policy guidance of the Italian Ministry for the Environment and the Protection of Land and Sea. has been established by Law no. 113 of 6 June 2008. 

This is a man-made or natural alteration of the environment, which causes disruption or permanent damage to the life of an area and which is not in balance with existing natural cycles.

Using the Mercalli Cancani Sieberg scale, this measures the effects of the earthquake on man, on buildings in the area struck by the quake and on the environment. Unlike the Richter Scale, the precise value of the intensity can only be attributed after observation of the damage produced by the earthquake.

A vast class of chemical composites made up of carbon and hydrogen, many of which, gases, liquids or solids, are the main elements of crude oil and natural gas, as well as of various natural substances (artificial resins, natural rubber, etc.). Due to their different structures they have different physical and chemical and can therefore be used in a large number of fields. Their fundamental characteristic is that they produce heat energy via rapid oxidation (in other words they burn). They also provide the raw material indispensable for the modern chemical industry, which for this reason is called petrol-chemical.

System, resource, process or structure, even virtual, whose destruction, interruption or even partial or temporary unavailability significantly weakens the normal efficiency and function of a country, as well as security and the economic and social system, including central and local Public Administration bodies.

These are plants that dispose of waste via a high-temperature combustion process (incineration) that emit gas effluent, ashes and dust. In more modern plants, the heat developed during combustion of waste is recuperated and used to produce steam, then used for the production of electricity. Facilities with recovery technology are called energy-recovery incinerators, or more commonly WtE or Waste to Energy plants.

See noise analysis.

MASW is a seismic exploration method that uses the generation of surface waves from an impulse source, called hammer, or from an aligned vibrating source with equidistant receivers, normally 24 with 1 metre wheel base, and progressively moved away.  The Masw test allows to determine a speed profile for the propagation of Rayleigh surface waves (Vr) in deep and to build the stratigraphy.

Method for surveying the subsoil based on measurement of variations in electric resistivity of the ground layers deep down. The resistivity of the ground, in other words the resistance that the ground opposes to the passage of an electric current, injected into the ground and measured at regular intervals on the surface along a linear path, depend on the water content: the less water present, the greater the resistivity. Because the water content is a function of the ground’s lithological characteristics, measuring resistivity makes it possible to reconstruct the formation of the soils deep underground.

Pyroclastic fragments measuring between 2 and 64 mm emitted during volcanic explosions.

Term used for totally or partially molten magma when this reaches the surface following an effusive or moderately explosive eruption. The term lava is also used for rocks formed when the erupted magma solidifies.

A 3-level scale, which defines, in relation to each type of risk, a scenario of events that may occur in a territory.
For the hydraulic and hydrogeological risks, levels of ordinary, moderate and high criticality are defined.
The assessment of criticality levels is the responsibility of the pheripheral functional centre, when activated, or by the central functional Centre, in accordance with the principle of subsidiarity.

Scale of alert of the national civil protection service used in case of an expected or underway emergency. The scale provides for the activation phase of risk prevention, and/or the various phases of emergency management.
The relationship between the levels of criticality assessed by a Functional Centre and the different levels of alert is established, uniquely and individually, by the Regions, and is adopted during special procedures.
The declaration and the adoption of the alert level of the civil protection system is always the responsibility of relevant local authorities (municipality, province and region) as defined in art. 108, D.lgs.112/98.

Organic waste with a high water content.

The thin external layer of the planet Earth, on average about 70 km thick, which includes the earth’s crust and the uppermost mantle.

Branch of geology which deals with the study of earth's crust forms and phenomena that modify it.

Description of a geometric succession of rock strata, in which can be distinguished different intervals due to the nature of the rocks that form them, regardless of the presence of fossil associations (basis of biostratigraphy) or the age of the rocks (basis of chronostratigraphy).

The phenomenon by which ground loses its shear resistance as a consequence of the application of dynamic actions such as seismic effects in non-draining conditions. The cause lies in the increase of interstitial pressures that follows the dynamic shaking: this increase, added to the initial value of the interstitial pressure, ends up by equalling the tensions normally applied, therefore cancelling effective tensions and as a consequence also resistance. Loose sandy surface soil deposits below the ground water table level are particularly susceptible to dynamic liquefaction.

Description of the geometric series  della successione geometrica delle rocce in profondità, distinte sulla base della loro natura – alluvioni, depositi lacustri, depositi vulcanici, calcari, ecc. – , a prescindere dalla presenza di associazioni fossilifere, base della biostratigrafia, o dall’età delle rocce, base della cronostratigrafia.

European civil protection modules are composed, on a voluntary basis, by Member States of the Union.
They are part of the civil protection response, as requested by the European Council and Parliament following the tsunami disaster in South-East Asia. There are currently 17 modules about: purification and water pumping; AIB campagign, wood fire-fighting with aeroplanes and helicopters; Usar teams urban search and rescue, also in caseof Nbcr - Nuclear biological chemical radiological - risk; medical assistance and evacuation; field hospitals; fields; Nbcr survey and sampling.

24 hour active centre that represents the operating component of the European Civil Protection Mechanism and lies in the Civil Protection Unit of the General Direction of Humanitarian Aid and Civil Protection. It provides countries with the access to a community platform of civil protection, where requests from EU or non-EU countries hit by a calamity and help offers of Member States are collected.

Constant observation of an event that has already happened or that could happen. Divided into:

- Environmental monitoring: control with detection and measurement over time of certain bio-chemical-physical parameters that characterise the environment:
- Instrumental monitoring: control with detection and measurement over time of certain chemical-physical-mechanical parameters, using recording receivers, such as seismographs.

Natural substance with a high temperature, which represents a heterogeneous system containing a prevalent liquid phase, a solid mineral phase and a gas phase in variable quantities. Magma is formed when the temperature and pressure conditions in the earth’s mantle or crust reach lead to partial fusion of the rocks. When magma reaches the earth’s surface it is called lava.

The European Civil Protection Mechanism is a strategy of the European Union to promptly respond to emergencies that may occur in territories inside or outside the European Union, through the share of resources in all the member countries. All the initiatives are based on the principle of subsidiarity, according to which all actions by the European Union must be undertaken in coordination and upon request of the emergency struck country. The Mechanism is managed by DG ECHO of the European Commission and the emergencies are dealt with by using european civil protection modules.  



Organisation by the civil protection system of the response to the emergency at the different levels of responsibility, also through the planning and activation of operations centres in the territory.

Structure composed by men and means with a specific function, that can be activated by constitution of the intervention device.

Prior identification of operations centres and emergency areas in the areas involved in emergency planning.

A simple and flexible tool for planning an emergency at different territorial levels of competence. The name comes from the idea of Emperor Octavian Augustus that “the value of planning is reduced in proportion to the complexity of the state of things”.

Any intervention to limit or permanently insulate the polluting source from the surrounding environment.

Control with a geodetic network that has the task of monitoring tectonic deformations (in other words of the earth’s crust), movements and deformation of the ground associated with the most intense seismic events. Monitoring also promotes development of knowledge about the tectonic processes that cause seismic activity.

SDivision of a territory on municipal scale into areas with homogeneous behaviour from a local seismic response profile, taking into consideration geological, geomorphological, and hydrogeological conditions able to produce amplification phenomena of the seismic signal and/or permanent deformation of the ground (landslides, liquefaction, compaction and settling).

Small amplitude seismic waves that originated from natural or man-made local sources, like sea waves, the wind, small earth movements, traffic, etc. The contribution of sources deep underground is negligible. (also see noise analysis).

The strongest shock during a seismic period or sequence.

A branch of seismology that studies the effects of earthquakes on the territory, in particular in the anthropologic context: built-up areas, individual buildings and people. The information is gathered both using “direct” macroseismic methods and also using “indirect” tools like telephone calls, the sending out of special questionnaires to authorities and to the people in the areas involved, etc. The information is translated into a “macroseismic observation” that allows an intensity value from the MCS (Mercalli Cancani Sieberg) macroseismic scale to be attributed to the areas involved.

Operations, even temporary, aimed at reducing risk in a certain environment and carried out promptly in the event of an emergency, with the primary goal of safeguarding human life.

The measurement of the energy liberated by an earthquake at his ipocentre. It is calculated starting from the amplitude of the seismic waves recorded by the seismograph, and it is given on a logarithmic scale of values of the energy recorded, called the Richter Scale. Each point of magnitude corresponds to an increase of around 30 times the energy: the energy developed by an earthquake of magnitude 6 is around 30 times greater than that produced by one of magnitude 5 and around 1000 times greater than that produced by an earthquake of magnitude 4.

All operations of the technical staff, including health unit and transport of wounded from the scene at PMA, and vice versa.

Displacement of ambulances and other sanitary means of transportation from Pma to hospitals, and viceversa, for hospitalization of victims.


A mass of air containing toxic substances.

Nuclear, biological, chemical or radiological substances able to provoke major damages to people, animals or things and spread the infection. This type of substances may be dispersed following industrial accidents, car crashes, wrong handling, employment for terrorist purposes, or after earthquakes, floods or other natural phenomena.  

Compulsory technical regulations that must be applied on seismic classified territories whenever a new building is projected or when existing building undergo renovation processes. To build respecting anti-seismic regulations guarantees the protection of the building from the earthquake effects: in that is the case, an anti-seismic building will not collapse, safeguarding the life of its inhabitants.

Emergency unit comprising men and equipment able to ensure catastrophe victims with an intermediate level of treatment between first aid and final treatment. This is a structure equipped for emergency surgery, intensive assistance for several hours and clinical observation of patients.

Heat waves are extreme meteorological conditions that occur during the summer, characterised by high temperatures, above usual values, that may last days or weeks.

Department of the United Nations responsible for bringing together humanitarian actors to ensure a coherent response to emergencies and coordinate humanitarian missions. OCHA also aims at assisting populations struck by disasters and various emergences, promoting planning activities, prevention and response, defending human rights.

Organismo liberamente costituito e senza fini di lucro che svolge o promuove attività di previsione, prevenzione e soccorso per eventi di protezione civile. Si avvalgono prevalentemente delle prestazioni personali, volontarie e gratuite dei propri aderenti, curandone anche le attività di formazione e addestramento. L’organizzazione è iscritta negli elenchi regionali, ed eventualmente nell’elenco nazionale del Dipartimento della Protezione Civile.

National network of the Civil Protection Department dedicated to permanent monitoring of seismic response in civil structures of zones at high seismic risk. When an earthquake occurs, the network provides the Department with data on the response of monitored buildings, and allows to evaluate from remote the damage extent almost in real time. It has a double task: monitoring relevant structures of the Department for the seimic emergency management and supply data for the creation of interpretative and predictive of the seismic conduct of structures.

Activities aimed at avoiding or minimising the possibility of damage occurring in the wake of a disaster. These include structural as well as non-structural intervention such as emergency planning, civil protection exercises, training and informing the public.

Functional device of selection and sanitary treatment of victims, placed along the borders of the safety area or in a central zone from area where the event occurred. It may be a structure - tents, containers - or a structured area to gather victims concentrate first treatment resources and organize the sanitary evacuation of wounded people.

Official document through which authorities organize the civil protection response to mitigate damages after a considerable accident. It is designed on scenarios that locate risk areas, namely the territory surrounding an industrial plant, where - presumably - effect of the event may occur.

Document prepared by the administrator of an industrial plant exposed to relevant risk, in order to be able to deal with it. Pei provides for the activation of internal emergency teams, along with fire fighters. The administrator must inform authorities about the event. 

A pit crater (also called a subsidence crater or collapse crater) is a depression, usually with a circular opening, formed by a sinking of the ground surface lying above a void or empty chamber, rather than by the eruption of a volcano or lava vent.  

Coordinated elaboration of the operative intervention procedures to be implemented when an expected event occurs in a certain scenario. 

Activities aimed at determining the causes of calamitous phenomena, in order to identify risks and define the territory concerned by the risk.

Plan drawn up by municipalities to adequately manage a possible emergency in their area, as provided for by DLgs 112/1998. It takes account of the various risk scenarios considered in the prevision and prevention programmes, on a provincial and regional level

Maximum ground acceleration value measured during an earthquake. This is a value of engineering interest used in planning to define the construction characteristics for buildings in seismic zones.

A generic term for all fragmented materials emitted during explosive volcanic activity.

An influenza pandemic is an epidemic of an influenza virus that spreads on a worldwide scale and infects a large proportion of the human population. In contrast to the regular seasonal epidemics of influenza, these pandemics occur irregularly.

Cognitive, regulatory and technical-operational tool, through which actions and usage rules for the conservation, protection, exploitation of land and water use are designed and planned, based on the physical and environmental characteristics of territory.


The parts into which, according to the plate tectonic heory, the earth’s crust is divided. The litosphere is made up of around a dozen main plates like a sort of puzzle, with pieces in continual movement. Earthquakes and volcanic activity are the most obvious manifestation of this vital aspect of the earth.

A component of seismic hazard due to the seismological characteristics of the area (type, size and depth of the seismic sources, energy and frequency of earthquakes). Basic seismic hazard calculates (usually using a probabilistic method), for a certain region and in a certain period of time, the parameter values corresponding to set excess probabilities. These parameters (speed, acceleration, intensity, spectrum ordinates) describe the shaking produced by the earthquake in conditions of rigid ground and with morphological irregularities (reference earthquake). This study is usually on a regional scale. One of the purposes of these studies is seismic classification classification on a large scale of the territory, with a view to programming prevention measures and emergency planning. It represents a base for definition of reference earthquakes for studying seismic microzonation.

Element of seismic hazard that depends on local characteristics (lithostratigraphic and morphological, see local effects). The study of local seismic hazard is carried out on a detailed scale starting with the results of basic seismic hazard studies (reference earthquake) and analysing the site’s geological, geomorphological, geotechnical and geophysical characteristics. It allows definition of local amplification and the possibility of occurrence ground instability phenomena. The most important result of this kind of study is the microzonation map.

This is a generic term used for all substances capable of controlling, limiting, warding off or destroying living organisms (microorganisms, animals or plants) considered to be toxic or of stopping their development.
The term “pesticide” also includes products for protection of plants, products used by vets to protect pets (for example, anti-flea collars for dogs).

Weather forecasts organized by the Weather Technical Group, adopted by the Department on the entire national territory for the following 72 hours, with the purpose of allowing the weather forecast areas of the peripheral Functional Centres to produre and render their own forecast on limited areas (on regional or provincial scale) and the Department to isse a national weather vigilance bulletin on a daily basis.

The Euro-Mediterranean Partnership (or Barcelona Process) started in 1995, following the Barcelona Declaration and establishes the politics of the European Union towards Mediterranean countries.

The partnership aims at strenghtening relations between the European Union and Partner Countries, to favour peace and stability through the reinforcement of political and security dialogue, promoting shared values such as democracy and legally constituted state.


Sizes and related indicators of the likely occurrence of preconfigured scenarios of an event, along with the consequent effects on the integrity of life, property, settlements and environment, if no action of contrast and containment - albeit temporary and provisional - occurs.

It is the simplest of synthetic polymers and it is the most common of plastics. It is often indicated with the abbreviation “PE”.

Flammable and dense liquid, found in some fields of the upper layers of the earth's crust. It consists of a mixture of various hydrocarbons

Practical activities to assess search and rescue intervention capacity. They are carried out and organised by each of the operating units of the Civil Protection National Service through the use of its own resources in terms of man power, means and materials.

Activities including the period of anticipation of the event, namely the technical-scientific knowledge of the risks of a territory, and the phase of prevention, namely the mitigation of risks. The result is the prediction and prevention programs that are a prerequisite for emergency planning, managed by the responsible authorities  for territory.


Set of rules that govern the management of the flow of information between subjects involved in an emergency, the warning, deployment and coordination of the components and operating units of the Civil Protection National Service.

The probability that a harmful event of a specific intensity occurs in a given area within a specified period, called return period. The dangerousness is function of the frequency of the event. In some cases, such as floods, it is possibile to estimate - within an acceptable approximation - the probability that a given event may occur within the return period. In other cases, such as some types of landslides, the estimate is more difficult.

Maximum velocity value of ground subject to seismic action which characterises the amplitude of the seismic motion at intermediate frequencies. The value indicates the potential damage of structures sensitive to intermediate frequencies, such as tall buildings or bridges.

The highest value of ground displacement recorded during an earthquake, necessary for characterising the amplitude of the seismic motion at low frequencies.