Multilateral Comenius Project Endogenous Hazards

An earthquake or a seism is a term used for the movements of the Earth that consist in vibrations of the Earth`s crust, propagated as waves which result from the clashes of the tectonic plates.

When an earthquake sets off shock waves will be released from the epicentre and they are usually called primary waves or “P” waves. They propagate longitudinally producing back and forth oscillations.

The “P” waves are followed by secondary waves or “ S” waves which propagate perpendicularly on the forward direction.

A third type, the surface waves provoke undulating of the soil and enhances the devastating effect of the secondary waves.

Measuring the earthquakes The most commonly known measuring scales are the Richter and Mercali scales.

The dimensions of the earthquakes. Lower than 2 magnitude earthquakes are called micro-earthquakes are not detected by people and are recorded only by local seismographs.

Larger magnitude or equal to 4-5 degrees earthquakes are powerful enough to be recorded by sensitive seismographs all over the globe and generally sensed by people.

Over 6 magnitude earthquakes are considered big earthquakes and the ones greater than 8 are considered major earthquakes.

There are various equipments to measure the characteristics of the earthquakes. Among these, the most important are the accelometers and seismographs.

Mercali scale, invented by the Italian seismologist Giuseppe Mercalli, is a scale that establishes the intensity of an earthquakes according to the degree of destruction of a building, constructions, according to the degree of deformations of the Earh`s crust and according to the reaction of people after the seismic shock.

The seismic hazards and the earthquakes in Romania.

Vrancea is the most active seismic region in Romania, each year producing an average of earthquakes of a larger than 4 degrees on Richter scale. Vrancea seismic region

The seismic warning centre of Bucharest patented an alerting system for the population, triggering some seconds before “S” wave releases from Vrancea to Bucharest. The seismic alarm activates for earthquakes larger than 4,5 on Richter scale. Bucharest map with region

In Romania there are more categories of earthquakes:  superficial, focal depth of under 5km.  crustal ( normal) with focal depth of between 5 and 30km.  intermediary, with focal depth of between 70 and 170 km.

Other seismic regions in Romania that produce crustal earthquakes are : Banat, Fagaras- Campulung, Maramures, Transilvania, Crisana, Campia Romana, North Dobrogea, seaside region of Black Sea and the south of Dobrogea. Here there is a plethora of low depth earthquakes ( more frequently between 5 and 30 km)

In the last 72 years. Romania has undergone a series of powerful earthquakes with the epicentre in Vrancea : -10 november 1940 (M=7,7; depth 160 km); - 4 march1977 (M=7,5; depth 100 km); - 30 august 1986 (M=7,2, depth140 km); - 30 may 1990 (M=6,9; depth 80 km).

The 1977 earthquake was a powerful earthquake which produced at on 4 th of March 1977 with devastating effects for Romania. The epicentre of the earthquake was localized at a depth of approx.100 km. The shock wave was felt in all the Balcanic Peninsula.

It had a magnitude of 7.2 degrees on Richter scale and did, in 56 seconds, victims of which only in Bucharest. The first seismic wave and the most powerful lasted 55 seconds, recording a tragic outcome.

Most damage was focused in Bucharest where over 33 buildings and large blocks collapsed and some houses totally destroyed.

Economic loses – There is no ball park figure of these but according to some calculations there were between 2 and 3 billion dollars of which 60% regarding buildings only.

Seismic hazards in Roman town and surrounding areas. Roman is placed in the great seismic area of Vrancea region, at a distance of 150 km from the epicentre zone.

This region was affected by the catastrophic earthquake of and the one of

Although seismic activities were recorded with the epicentre in Tazlau region, the possibility of reoccurrence of these movements in Neamt county is diminished.

The most recent map of the buildings prone to seismic activity from Roman town dates back in 2010 and includes some apartment buildings of which the most hazardous are the ones built on Stefan cel Mare street ( former middle of the town).

Four houses are classified in the 1st seismic hazard scale and other five were classified in the 2 nd seismic hazard scale. ( a total of 133 people).

The newest apartment buildings of the town were built after the 1977 earthquake and the foundations, main structures are extremely well made.

The Emergency Situations Inspectorate “ Petrodava” of Neamt county and the Fire Department of Roman town periodically develop prevention and information activities of the population on the first aid thematic in case of earthquakes.

Recently recorded earthquakes In Romania :

This presentation was made by Romanian students: - GAVRIL RAZVAN - BUTNARU ANDREI-BOGDAN - LUNGU GEORGIANA From L.P.S. Roman