Budapest rocks
An earthquake measuring 4.1 on the Richter scale caused minor damage in areas on the edge of Budapest on New Year’s Eve. Many people living in the capital felt a disconcerting tremor lasting for a few seconds. It was a reminder that the earthquake threat in Hungary is limited, but not to be underestimated.
The tremor occurred at around 2.45 pm, causing damage to buildings immediately around the epicentre, in some towns on the eastern edge of Budapest. A sports hall in Pécel that had recently been renovated suffered cracks.
Fears renewed
The seconds of the shock elapsed without major incident, but unease remained. Hungary has low-to-average tectonic activity. The situation in Hungary will not be as severe as a Japanese newspaper predicted in 1979, envisaging a horror scenario of the Gellért hill sliding into the Danube. “The origin of the fully unjustified prediction has remained mysterious,” recalls László Tóth, director of the institute forearthquake research, Geo Risk. “But for a while this newspaper report caused unease.”
The facts, however, are the following: yearly Hungarian seismographs register around 150-200 mini earthquakes that are not perceptible to humans. The number of quakes that are actually felt by parts of the population is between 15 and 20. Ten major earthquakes occured in recent centuries. Information about their strength is given by historical notes and in some cases measurements using instruments. There have been earthquakes measuring over 5.5 in Komárom (1763, 1783, 1806, 1851), Kecskemét (1908, 1911), Érmellék (1834), Eger (1925), Dunaharaszti (1956) and Berhida (1985).
Previously fatal
The largest catastrophe was on 28 June, 1763 in the north Hungarian city of Komárom. The quake with an estimated magnitude of 6.3 caused the death of 63 people and 279 buildings, including seven churches collapsed. The quake with the most serious consequences in the capital was fifty years ago: in Dunaharaszti, a town on the southern edge ofBudapest , hundreds of buildings were damaged by a quake of magnitude 5.3. Some houses were reduced to ruins. In a study, seismologist Péter Varga comments that the consequences would probably have been five to ten times worse of the epicentre had been 10.15 kilometres north in the centre of the capital.
“The maximum strength of earthquakes in Hungary is around 6.5”, GeoRisk director Tóth said. The Institute for Earthquake Research offers a service for local risk assessment. On the www.foldrenges.hu website, the probabilities of quakes in different areas are displayed. The figures are based on data from the past 475 years and are believed to have a 90% likelihood for a time frame of 50 years.
Particular attention is given to the Paks nuclear power situation. GeoRisk’s monitoring system there detects and evaluates earthquakes from magnitude 1 rather than 1.5.
Not up to EUROCOD
Charles Richter, the creator of the first magnitude scale, stressed the importance of construction for protecting against earthquakes: “People are not killed by earthquakes, but by collapsing buildings”. An important goal for Hungary is the adoption of the European norm for the construction of building inearthquake areas, EUROCOD 8. The drafting of the relevant bill is the task of a government committee formed in December 2003. However, according to its own assessment at a forum in June 2006, the work has not yet gone beyond the preliminary stage.
Tóth points to unfavourable tendencies, for example, in older multi-storey buildings in Budapest: “Changes are often made to the structure of the building, for example by constructing shops on the ground floors. That lowers theearthquake resistance of the buildings.”
At a Council of Europe conference in 1991 a warning was given that vulnerability to earthquakes has increased due to a rise in population, the insecure ground consistency of large cities and complicated infrastructure.
(source: The Budapest Times)
Fears renewed
The seconds of the shock elapsed without major incident, but unease remained. Hungary has low-to-average tectonic activity. The situation in Hungary will not be as severe as a Japanese newspaper predicted in 1979, envisaging a horror scenario of the Gellért hill sliding into the Danube. “The origin of the fully unjustified prediction has remained mysterious,” recalls László Tóth, director of the institute forearthquake research, Geo Risk. “But for a while this newspaper report caused unease.”
The facts, however, are the following: yearly Hungarian seismographs register around 150-200 mini earthquakes that are not perceptible to humans. The number of quakes that are actually felt by parts of the population is between 15 and 20. Ten major earthquakes occured in recent centuries. Information about their strength is given by historical notes and in some cases measurements using instruments. There have been earthquakes measuring over 5.5 in Komárom (1763, 1783, 1806, 1851), Kecskemét (1908, 1911), Érmellék (1834), Eger (1925), Dunaharaszti (1956) and Berhida (1985).
Previously fatal
The largest catastrophe was on 28 June, 1763 in the north Hungarian city of Komárom. The quake with an estimated magnitude of 6.3 caused the death of 63 people and 279 buildings, including seven churches collapsed. The quake with the most serious consequences in the capital was fifty years ago: in Dunaharaszti, a town on the southern edge ofBudapest , hundreds of buildings were damaged by a quake of magnitude 5.3. Some houses were reduced to ruins. In a study, seismologist Péter Varga comments that the consequences would probably have been five to ten times worse of the epicentre had been 10.15 kilometres north in the centre of the capital.
“The maximum strength of earthquakes in Hungary is around 6.5”, GeoRisk director Tóth said. The Institute for Earthquake Research offers a service for local risk assessment. On the www.foldrenges.hu website, the probabilities of quakes in different areas are displayed. The figures are based on data from the past 475 years and are believed to have a 90% likelihood for a time frame of 50 years.
Particular attention is given to the Paks nuclear power situation. GeoRisk’s monitoring system there detects and evaluates earthquakes from magnitude 1 rather than 1.5.
Not up to EUROCOD
Charles Richter, the creator of the first magnitude scale, stressed the importance of construction for protecting against earthquakes: “People are not killed by earthquakes, but by collapsing buildings”. An important goal for Hungary is the adoption of the European norm for the construction of building inearthquake areas, EUROCOD 8. The drafting of the relevant bill is the task of a government committee formed in December 2003. However, according to its own assessment at a forum in June 2006, the work has not yet gone beyond the preliminary stage.
Tóth points to unfavourable tendencies, for example, in older multi-storey buildings in Budapest: “Changes are often made to the structure of the building, for example by constructing shops on the ground floors. That lowers theearthquake resistance of the buildings.”
At a Council of Europe conference in 1991 a warning was given that vulnerability to earthquakes has increased due to a rise in population, the insecure ground consistency of large cities and complicated infrastructure.
(source: The Budapest Times)
posted by GG at 9:58 PM
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