Sixty-five years ago an earthquake shook Budapest
Hungarian version of the article: Hat ház dőlt össze Budapesten a 65 évvel ezelőtti földrengésben
January 9, 2021 at 10:00 AM
The year 1956 got off to a shaky start - on the morning of 12 January, residents in southern Budapest were woken by an alarming phenomenon: the earth was moving. The MTI published the following report the next day:
“The earthquake felt at 6:46:12 and followed by an aftershock at 8:41, could be felt in several parts of the country but was not of national proportion. The tremors caused significant damage in Budapest and Pest county, while minor damage has been reported from Baranya, Bács-Kiskun, Fejér, Komárom, Szolnok, Tolna and Veszprém counties, mainly in non-brick buildings.”
Taksony and Dunaharaszti were the wort-afflicted, with the tremors leading to two deaths, A total of 38 injuries were recorded, of which 15 were classified as light. 3144 of the 3500 houses in Dunaharaszti suffered damage.
Severe damage was reported in Budapest. Six houses collapsed in the 20th and 21st Districts, and several others were damaged. The electrical network was also damaged, and the overhead powerlines of the Soroksár suburban railway also broke. Some buildings of the Csepel Automotive Factory were also damaged.
Even more interesting was another consequence of the quake. The water flow from the heat sources that supply the Rudas Bath increased temporarily, before returning to the usual level.
A map showing the extent of the earthquake (Source: Élet és Tudomány, 7 March 1956)
The earthquake, which measured 5.6 on the Richter scale, was caused by the movement of the dolomite slab that can be considered the continuation of Gellért Hill under Csepel Island. The earthquake came as a surprise because the previous quake which could be felt by the public happened around Eger in 1925.
Budapest had never previously been affected by a major quake. Since 1956, only a single tremor with an epicentre within the capital has been recorded. On 17 October 2000, an earthquake with a magnitude of 1.5 on the Richter-scale was measured. Nevertheless, smaller tremors are a common occurrence around the city. Over the past 25 years, there have been a total of 6 earthquakes on the borders of Budapest, but none of these has reached a magnitude of 3.
Residents of the city could also feel the 4.7 magnitude earthquake that shook Oroszlány on 29 January 2011. Luckily, no injuries or significant damage was reported in Budapest. A few minor events were recorded. Cracks appeared on a panel house in the 3rd District, while plaster fell from the walls of another in Gazdagrét within the 11th District. Following the tremor, the condition of every bridge, overpass, and underpass in the city was checked - all were deemed to be safe. In principle, Budapest's bridges should survive such a quake even if the epicentre was in Budapest.
The Richter scale is not linear, but logarithmic. This means that rather than growing like the Celsius scale – in which the same range separates each degree from the previous and the next – on the Richter-scale a level 4 quake is about 35-times more powerful than a level 3 quake. A 4.5 earthquake releases as much energy as the nuclear bomb detonated above Nagasaki. On average, 6200 quakes of this magnitude occur on the Earth each year.
The walls of the house collapsed in the earthquake (Photo: Mandab.hu/Katasztrófavédelem Központi Múzeuma)
The power of earthquakes can be seen in reports of the Croatian tremors being felt in Budapest's taller buildings. True, the Croatian earthquake was much stronger, reaching a magnitude of 6.3.
Could a similar quake occur in Hungary? In principle, yes. There have actually been similar tremors before, one near Komárom in 1763 is estimated to have been a 6.2 or 6.3. The tremor not only caused damage in Komárom but destroyed the church in Zsámbék.
Several earthquakes have been felt in Hungary over the last 65 years, but luckily, none have led to a loss of life.
Hopefully, this is a trend that will continue in the following years and decades. The fact that Hungary is relatively calm - from a tectonic point of view - gives us some hope. On average 100–200 smaller, barely perceivable tremors occur, and 4–5 which can be felt. In general, a single quake with a magnitude above 4, and the potential to cause serious damage happens each decade.
Cover photo: Firefighters during damage control (Magyar Tűzoltó, 1 February 1956)