Erzincan earthquake in 1939
| Erzincan earthquake | |||
|---|---|---|---|
|
|||
| Coordinates | 39 ° 46 '16 " N , 39 ° 34' 37" E | ||
| date | December 26, 1939 UTC | ||
| Time | 23:57:23 UTC | ||
| intensity | XII on the MM scale | ||
| Magnitude | 7.8 M W | ||
| depth | 20 km | ||
| epicenter | Erzincan | ||
| country | Turkey | ||
| Tsunami | Yes | ||
| dead | 32,962 | ||
The Erzincan earthquake shook the Turkish city of Erzincan and the surrounding area on December 27, 1939 at around 01:57 local time with a magnitude of 7.8 M w . Low temperatures, heavy rainfall and flooding impaired rescue and relief work. About 33,000 people were killed in the deadliest earthquake of the 20th century in Turkey
Tectonic and meteorological background
The North Anatolian Fault Zone , the plate boundary between the Eurasian and Anatolian plates, runs through northern Turkey . At this transform fault , the significantly smaller Anatolian plate moves westward in relation to the Eurasian plate at a speed of around 10 to 20.5 millimeters per year. The North Anatolian Fault is one of the most seismically active regions in the world, and earthquakes occur there again and again. On November 21, 1939, a 5.9 magnitude earthquake occurred about 75 kilometers to the east on the same fault, which may have a seismic connection with the Erzincan earthquake.
The meteorological conditions in the region were extremely adverse at the time of the main quake . Around the 9./10. December began a cold spell , heavy snowfall set in and storms developed on the southern coast of the Black Sea . On December 24th, temperatures of −20 ° Celsius were measured in northeastern Bulgaria and the Danube froze over. After the quake, the air pressure was low , and the lowest temperature in Erzincan on December 28th was −30 ° Celsius.
earthquake
The earthquake had its epicenter less than eight kilometers northeast of central Erzincan. Its hypocenter was 20 kilometers below the surface. Erzincan was therefore the hardest hit. Numerous fires broke out in the ruins, which could hardly be fought due to broken water pipes and destroyed roads. Other very hard hit cities were Sivas and Tokat . There was also damage in Yozgat , Amasya , Samsun , Altınordu , Giresun , Malatya , Turhal , Gümüşhane Suşehri , Koyulhisar , Reşadiye and Niksar as well as in numerous villages. The zone of worst destruction was approximately 15 × 300 kilometers along the North Anatolian fault zone. Telegraph lines, roads and rail connections were interrupted, bridges collapsed. The effects of the vibrations resulted in soil liquefaction , landslides , rock falls and the formation of large cracks in the ground. An offset of the clods reaching to the earth's surface (surface rupture) had a length of 360 kilometers, making it the longest such offset since the beginning of instrumental earthquake research. The displacement reached heights of 1 to 2 meters and a lateral displacement of 2.3 to 8.8 meters.
A small tsunami formed in the Black Sea. In the port of Fatsa , the sea initially retreated about 50 meters before tidal waves hit the land and flooded up to a height of 20 meters above normal sea level. It is not clear whether the tsunami was a direct effect of the quake or whether it was triggered indirectly, for example by a landslide.
Numerous aftershocks occurred along the North Anatolian fault zone. Seven severe aftershocks occurred in the first hours after the main quake.
The first train with aid deliveries on the new Sivas-Erzurum rail link stopped at Sivas because of the destroyed tracks and was snowed two meters high. In the south, the snowfall turned into heavy rain, which on December 31 led to flooding in the Diyarbakır region and other places. On January 1, 1940, another storm broke out over the Black Sea. Epidemics broke out in the affected areas, claiming further deaths. In agriculture, the events made themselves felt months later through a low harvest yield.
The Erzincan earthquake and other earthquakes in the following years were decisive for the exploration of the North Anatolian fault zone, which a few years later was recognized as an active transform fault.
literature
- Halil Gürsoy, Orhan Tatar, Zafer Akpınar, Ali Polat, Levent Mesci, Doğan Tunçer: New observations on the 1939 Erzincan Earthquake surface rupture on the Kelkit Valley segment of the North Anatolian Fault Zone, Turkey. In: Journal of Geodynamics. Volume 65, 2013, pp. 259-271, DOI: 10.1016 / j.jog.2012.06.002 (English).
- Boyko Ranguelov, Arnd Bernaerts: The Erzincan 1939 Earthquake - A Sample of the Multidisaster Event. In: Second Balkan Geophysical Congress and Exhibition. 1999, p. 62f., Digital version online (PDF; 18 kB) at balkangeophysoc.gr (English).
- Hamit N. Pamir, İhsan Ketin : The Anatolian earthquake at the end of 1939. In: Geologische Rundschau. Volume 32, No. 3, 1941, pp. 279-287.
- E. Tillotson: The Earthquake in Turkey. In: Nature. Volume 145, 1940, pp. 13-15, DOI: 10.1038 / 145013a0 (English).
supporting documents
- ↑ Significant Earthquake - TURKEY: ERZINCAN. NOAA , accessed July 4, 2020.
- ↑ Significant Earthquake - TURKEY: ERZINCAN. NOAA, accessed July 4, 2020.
- ^ M 7.8 - eastern Turkey. USGS , accessed July 4, 2020.
- ↑ Tsunami Event - TURKEY: SOUTH BLACK SEA. NOAA, accessed July 4, 2020.