The 1933 Kos earthquake struck the

Aegean Sea The Aegean Sea ; tr, Ege Denizi (Greek language, Greek: Αιγαίο Πέλαγος: "Egéo Pélagos", Turkish language, Turkish: "Ege Denizi" or "Adalar Denizi") is an elongated embayment of the Mediterranean Sea between Europe and Asia. It ...

region on 23 April. It measured 6.4 and had an epicenter offshore, near Kos, Greece. The earthquake collapsed many buildings on Kos,

Nisyros Nisyros also spelled Nisiros ( el, Νίσυρος, Nísiros) is a volcanic Greek island and municipality located in the Aegean Sea. It is part of the Dodecanese group of islands, situated between the islands of Kos and Tilos. Its shape is appro ...

and other islands. At least 181 people were killed with a possible death toll reaching several hundred.

Tectonic setting

The eastern

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

is a region of dynamic plate interactions involving the

Eurasian Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago ...

and Aftican plates—dominated by the

North Anatolian Fault The North Anatolian Fault (NAF) ( tr, Kuzey Anadolu Fay Hattı) is an active right-lateral strike-slip fault in northern Anatolia, and is the transform boundary between the Eurasian Plate and the Anatolian Plate. The fault extends westward fro ...

and Hellenic subduction zone. The Aegean Sea is a seismically active and complex area in the eastern Mediterranean Sea that experiences frequent large earthquakes and tsunamis. The

Aegean Sea Plate The Aegean Sea Plate (also called the Hellenic Plate or Aegean Plate) is a small tectonic plate located in the eastern Mediterranean Sea under southern Greece and western Turkey. Its southern edge is the Hellenic subduction zone south of Crete, ...

formed between the divergent boundary in Greece, separating it from the Eurasian Plate; and the subduction zone in the south separating it from the African Plate. The east Aegean Sea is a region of

extensional tectonics Extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary body's crust or lithosphere. Deformation styles The types of structure and the geometries formed depend on ...

; around Kos, this tectonic setting formed the Kos and Gökova

graben In geology, a graben () is a depressed block of the crust of a planet or moon, bordered by parallel normal faults. Etymology ''Graben'' is a loan word from German, meaning 'ditch' or 'trench'. The word was first used in the geologic contex ...

s, Quaternary submarine structures trending northeast–southwest and east–west, respectively. Earthquakes in the area are associated with normal faults that accommodates extension. Earthquakes in 1493, 1869 and 2017 caused severe damage and casualties.

Earthquake

Prior to 1933, Kos was damaged by an intermediate-depth () 7.4 earthquake. The April 1933 earthquake had magnitudes between 6.43 and 6.70; the

International Seismological Centre The International Seismological Centre (ISC) is a non-governmental, nonprofit organisation charged with the final collection, definitive analysis and publication of global seismicity. The ISC was formed in 1964 as an international organisation ...

cataloged it at 6.4. The Modified Mercalli intensity on Kos ranged from VIII (''Severe'') to X (''Extreme''). Intensity IX–X (''Violent''–''Extreme'') was observed at Antimachia, Kardamaina and Kos. On Nissyros, the seismic intensity was VI–VII (''Strong''–''Very strong''). On

Rhodes Rhodes (; el, Ρόδος , translit=Ródos ) is the largest and the historical capital of the Dodecanese islands of Greece. Administratively, the island forms a separate municipality within the Rhodes regional unit, which is part of the So ...

, the earthquake was felt V–VI (''Moderate''–''Strong'').

Impact

In Kos historic city center, 90 percent of homes were demolished and only some government buildings were intact. Only 50 percent of homes were decimated in the new city. The Church of Agios Nikolaos was badly damaged and has to be torn down. At Pyli, a village west of the city, there was heavy damage. Almost all homes in Antimakheia were destroyed, and the village of Kardamena was near completely ruined. On Nissyros, the villages of Emporio, Pali, Mandraki and Nikia were damaged. Slight damage also occurred at

Bodrum Bodrum () is a port city in Muğla Province, southwestern Turkey, at the entrance to the Gulf of Gökova. Its population was 35,795 at the 2012 census, with a total of 136,317 inhabitants residing within the district's borders. Known in ancient t ...

, Turkey. The death toll ranged from 181 to several hundreds. Various press reports estimated 200–300 deaths on Kos. Only 122 victims were named. In Kos city, the death toll was reexamined to 178. Three more deaths occurred at Pyli. The number of injured was 600 to several thousand. Various press reports also stated between 20 and 100 deaths or no deaths on Nissyros.

Tsunami

The island population and mass media continues to suppose a

tsunami A tsunami ( ; from ja, 津波, lit=harbour wave, ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explo ...

struck the island but no reports exist. A newspaper reported ebb tide at Kos port for several tens of meters although it is unclear when did it occur. No coastal uplift associated with the earthquake was documented. Reports of waves likely were due to strong wind rather a tsunami associated with the earthquake.

References

{{Earthquakes in Greece 1933 earthquakes Earthquakes in Greece 1933 in Greece April 1933 events

Tectonic setting

Earthquake

Impact

Tsunami

See also

References