1894 Atalanti earthquakes
  Istanbul Athens  | |
| UTC time | Doublet earthquake: |
|---|---|
| 1894-04-20 15:52 | |
| 1894-04-27 19:42 | |
| Local date | 20 April 1894 27 April 1894 |
| Magnitude | |
| 6.7 Mw | |
| 6.9 Mw | |
| Depth | 10 km (6.2 mi) |
| Epicenter | 38°39′N 23°05′E / 38.65°N 23.08°E |
| Areas affected | Greece, Locris |
| Max. intensity | MMI X (Extreme) |
| Casualties | 255 |
The first of the 1894 Atalanti earthquakes occurred on 20 April 1894 at 16:52 UTC, with a magnitude of 6.4 on the moment magnitude scale and a maximum perceived intensity of X on the Mercalli intensity scale. It was followed seven days later on 27 April at 19:42 UTC by the second, with a magnitude of 6.9 and had a maximum intensity of X. These two earthquakes caused widespread damage in the Locris area, causing a total of 255 deaths.[1]
Earthquake overview
[edit]The 1894 Atalanti earthquakes, occurring on 20 and 27 April, significantly impacted Central Greece, particularly affecting the Locris region around the town of Atalanti. These earthquakes involved movements along the Atalanti Fault, a major geological structure running east-west and inclined to the north. The first earthquake on 20 April had an estimated magnitude of approximately 6.7, and the subsequent quake on 27 April was even stronger, estimated around magnitude 7.0. The earthquakes resulted in considerable damage to buildings, infrastructure, and settlements, and triggered substantial geological changes, including surface ruptures and alterations in the local landscape.[2]
The earthquakes' epicentres were closely associated with the Atalanti Fault's segments, extending for about 35 kilometres. Surface ruptures caused by the earthquakes were clearly visible, marking the earth's displacement along the fault line. In addition to surface damage, the quakes led to significant environmental impacts, such as landslides and changes in groundwater levels, influencing local water sources and agricultural lands.[2]
These seismic events profoundly affected the region's inhabitants, with many homes destroyed and significant loss of life and injuries reported. Historical accounts describe widespread devastation, prompting extensive reconstruction and relief efforts in the aftermath. The 1894 earthquakes remain significant in historical records as examples of destructive seismic activity in Greece, highlighting the persistent seismic hazards associated with active fault lines in the region.[2]
Historical significance
[edit]Prior to the 1894 earthquakes, the Atalanti area had been seismically quiet for over 1300 years, with no significant earthquakes recorded since at least 551 AD. This long period of seismic quiescence made the 1894 events particularly noteworthy to seismologists studying patterns of earthquake occurrence in historically active regions.[3]
Geological effects
[edit]The mainshock caused extensive surface faulting from Martino to Atalanti, covering about 25 km. Field reports documented normal faulting patterns, with researchers noting a seismic wave that flooded the Atalanti Gulf coastline. Another recorded effect was the increase in water levels at the hot springs in Loutra Aidhipsou.[3]
Modern implications
[edit]A century after these events, researchers from the University of Athens used the European Macroseismic Scale (EMS92) to re-evaluate these historical earthquakes. Their findings suggest that if similar earthquakes occurred today, Athens would experience ground accelerations at least 20% higher than in 1894. This increased vulnerability stems from the city's expansion onto unfavourable soil conditions and the proliferation of high-rise buildings over the past century, highlighting ongoing seismic risks to the Greek capital.[3]
See also
[edit]References
[edit]- ^ Albini P. & Pantosti D. (2004). "The 20 and 27 April 1894 (Locris, Central Greece) Earthquake Sources through Coeval Records on Macroseismic Effects" (PDF). Bulletin of the Seismological Society of America. 94 (4). Seismological Society of America: 1305–1326. Bibcode:2004BuSSA..94.1305A. doi:10.1785/012003174.
- ^ a b c Ganas, Athanassios; Karakostas, Vassilios; Papadimitriou, Eleftheria (2006). "A reappraisal of the 1894 Atalanti earthquake surface ruptures, central Greece". Bulletin of the Geological Society of Greece. 39 (4): 1635–1646. doi:10.12681/bgsg.17239.
- ^ a b c Makropoulos, K.C.; Kouskouna, V. (1994). "The 1894 April 20 and 27 Atalanti earthquakes: 100 years after—lessons learnt". Proceedings and Activity Report of the 1992–94 XXIV European Seismological Commission. 1: 61–71.
- Ganas, A., Roberts, G.P., & Memou, Tz. 1998. Segment boundaries, the 1894 ruptures and strain patterns along the Atalanti Fault, Central Greece. Journal of Geodynamics, 26: 2–4, 461–486.
- Ganas, A, Sokos, E, Agalos, A, Leontakianakos, G, Pavlides S, 2006, Coulomb stress triggering of earthquakes along the Atalanti Fault, central Greece: Two April 1894 M6+ events and stress change patterns. Tectonophysics, 420, 357–369.
- Nature, volume 50, 607–607 (18 Oct 1894), doi: 10.1038/050607a0.
- Pantosti, D., P. M. De Martini, D. Papanastassiou, F. Lemeille, N. Palyvos and G. Stavrakakis, 2004, Paleoseismological Trenching across the Atalanti Fault (Central Greece): Evidence for the Ancestors of the 1894 Earthquake during the Middle Ages and Roman Times, Bulletin of the Seismological Society of America; v. 94; no. 2; p. 531–549; DOI: 10.1785/0120020207
- Papavassiliou, A. (1894a,b). Sur le tremblement de terre de Locride (Grece) du mois d' Avril 1894, C. R. Acad. Sci. Paris 19, 112–114 & 380–381.
- Richter, C. F. (1958). Elementary Seismology, Freeman, San Francisco, 768 pp.