The 1766 Istanbul earthquake was a strong
earthquake
An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they ...
with
epicenter
The epicenter (), epicentre, or epicentrum in seismology is the point on the Earth's surface directly above a hypocenter or focus, the point where an earthquake or an underground explosion originates.
Determination
The primary purpose of a ...
in the eastern part of the
Sea of Marmara
The Sea of Marmara, also known as the Sea of Marmora or the Marmara Sea, is a small inland sea entirely within the borders of Turkey. It links the Black Sea and the Aegean Sea via the Bosporus and Dardanelles straits, separating Turkey's E ...
, in the
Çınarcık Basin The Çınarcık Basin is a submarine tectonic basin located in the Sea of Marmara, in Turkey. Geography
The Çınarcık basin gets its name from Çınarcık, a town and district of the Yalova Province in the Marmara region of Turkey. It is the ea ...
(or near the
Princes' Islands
The Princes' Islands (; the word "princes" is plural, because the name means "Islands of the Princes", , ''Pringiponisia''), officially just Adalar (); alternatively the Princes' Archipelago; is an archipelago off the coast of Istanbul, Turkey, ...
, north of the basin)
which occurred in the early hours of Thursday morning, 22 May 1766.
The earthquake had an estimated
magnitude
Magnitude may refer to:
Mathematics
*Euclidean vector, a quantity defined by both its magnitude and its direction
*Magnitude (mathematics), the relative size of an object
*Norm (mathematics), a term for the size or length of a vector
*Order of ...
of 7.1 on the
surface-wave magnitude
The surface wave magnitude (M_s) scale is one of the magnitude scales used in seismology to describe the size of an earthquake. It is based on measurements of Rayleigh surface waves that travel along the uppermost layers of the Earth. This mag ...
scale,
and caused effects in a vast area extending from
Izmit to Rodosto (now
Tekirdağ
Tekirdağ () is a city in northwestern Turkey. It is located on the north coast of the Sea of Marmara, in the region of East Thrace. The city forms the urban part of the Süleymanpaşa district, with a population of 186,421 in 2022.
Tekirdağ ...
).
In this area, the earthquake was followed by a
tsunami
A tsunami ( ; from , ) 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 underwater explosions (including detonations, ...
which caused significant damage. The earthquake of 1766 was the last major earthquake to rock
Istanbul
Istanbul is the List of largest cities and towns in Turkey, largest city in Turkey, constituting the country's economic, cultural, and historical heart. With Demographics of Istanbul, a population over , it is home to 18% of the Demographics ...
because of a rupture of the
North Anatolian Fault
The North Anatolian Fault (NAF; ) is an active right-lateral strike-slip fault in northern Anatolia, and is the transform boundary between the Eurasian plate and the Anatolian sub-plate. The fault extends westward from a junction with the Ea ...
in the Marmara region.
Geology
The
Sea of Marmara
The Sea of Marmara, also known as the Sea of Marmora or the Marmara Sea, is a small inland sea entirely within the borders of Turkey. It links the Black Sea and the Aegean Sea via the Bosporus and Dardanelles straits, separating Turkey's E ...
is a
pull-apart basin
In geology, a basin is a region where subsidence generates accommodation space for the deposition of sediments. A pull-apart basin is a structural basin where two overlapping (en echelon) strike-slip faults or a fault bend create an area of crust ...
formed at a
releasing bend in the
North Anatolian Fault
The North Anatolian Fault (NAF; ) is an active right-lateral strike-slip fault in northern Anatolia, and is the transform boundary between the Eurasian plate and the Anatolian sub-plate. The fault extends westward from a junction with the Ea ...
(NAF), a right-lateral
strike-slip fault
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...
.
East of the Sea of Marmara the NAF splits into three major branches; while the sinuous southern branch goes inland in a southwesterly direction up to
Ayvacık, where it reaches the
Aegean Sea
The Aegean Sea is an elongated embayment of the Mediterranean Sea between Europe and Asia. It is located between the Balkans and Anatolia, and covers an area of some . In the north, the Aegean is connected to the Marmara Sea, which in turn con ...
near the southern mouth of the
Dardanelles
The Dardanelles ( ; ; ), also known as the Strait of Gallipoli (after the Gallipoli peninsula) and in classical antiquity as the Hellespont ( ; ), is a narrow, natural strait and internationally significant waterway in northwestern Turkey th ...
, the other two major branches (northern and central) of the NAF, being under the Sea of Marmara about apart, form the Marmara pull-apart basin, meeting again under the northeast Aegean Sea.
This local zone of
extension
Extension, extend or extended may refer to:
Mathematics
Logic or set theory
* Axiom of extensionality
* Extensible cardinal
* Extension (model theory)
* Extension (proof theory)
* Extension (predicate logic), the set of tuples of values that ...
occurs where this
transform boundary between the
Anatolian Sub-Plate
The Anatolian plate is a continental tectonic plate lying under Asiatic part of Turkey, known as Anatolia. Most of the country of Turkey is located on the Anatolian plate. The plate is separated from the Eurasian plate and the Arabian plate b ...
and the
Eurasian plate steps northwards to the west of
İzmit
İzmit () is a municipality and the capital Districts of Turkey, district of Kocaeli Province, Turkey. Its area is 480 km2, and its population is 376,056 (2022). The capital of Kocaeli Province, it is located at the Gulf of İzmit in the Sea ...
from the Izmit Fault to the
Ganos
Ganos (Greek: Γάνος), now known as Gaziköy, is a neighbourhood of the municipality and district of Şarköy, Tekirdağ Province, Turkey. Its population is 372 (2022). It is a historically important town, located on the Sea of Marmara, benea ...
Fault. Inside the Sea of Marmara there is a smaller pull-apart basin, named the ''North Marmara fault System'' (NMFS), which connect the three submarine basins (from west to east): Tekirdağ, Central and Çınarcık) with the Izmit and Ganos Fault (both inland).
Near
Istanbul
Istanbul is the List of largest cities and towns in Turkey, largest city in Turkey, constituting the country's economic, cultural, and historical heart. With Demographics of Istanbul, a population over , it is home to 18% of the Demographics ...
the northern side of the NMFS pull-apart coincides with the northern branch of the NAF and is a single main fault segment with a sharp bend.
To the west, the fault trends west–east and is pure strike-slip in type. To the east, the fault is northwest–southeast trending and shows evidence of
both normal and strike-slip motion.
In 1766, the rupture of the fault happened either under the
Princes' Islands
The Princes' Islands (; the word "princes" is plural, because the name means "Islands of the Princes", , ''Pringiponisia''), officially just Adalar (); alternatively the Princes' Archipelago; is an archipelago off the coast of Istanbul, Turkey, ...
or, more probably, under the
Çınarcık Basin The Çınarcık Basin is a submarine tectonic basin located in the Sea of Marmara, in Turkey. Geography
The Çınarcık basin gets its name from Çınarcık, a town and district of the Yalova Province in the Marmara region of Turkey. It is the ea ...
, since a more central break could not have caused the great
tsunami
A tsunami ( ; from , ) 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 underwater explosions (including detonations, ...
that struck Istanbul and the
Gulf of İzmit
Gulf of İzmit (), also referred to as İzmit Bay, is a bay at the easternmost edge of the Sea of Marmara, in Kocaeli Province, Turkey. The gulf takes its name from the city of İzmit. Other cities and towns around the bay are Gebze, Körfez, ...
, although this had been produced by a submarine
landslide
Landslides, also known as landslips, rockslips or rockslides, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, mudflows, shallow or deep-seated slope failures and debris flows. Landslides ...
.
The 1766 event has been the last one caused by a rupture of the NAF in the Marmara region;
successive large events which caused extensive damage in Istanbul, like
the earthquake of 10 July 1894 (with epicenter in the Gulf of İzmit) and
that of 9 August 1912 (with epicenter northwest of
Marmara Island
Marmara Island () is a Turkish island in the Sea of Marmara. With an area of , it is the largest island in the Sea of Marmara and the second-largest island of Turkey - after Imbros, Gökçeada (formerly ; ''Imvros''). It is the center of Marmar ...
), have to be considered isolated events caused by the non uniform stress relief during the 18th century earthquake sequence, to which the 1766 event belongs.
Since the
second last major event with an epicenter in the Istanbul region occurred in 1509, a recurrence interval of 200 to 250 years has been hypothesized.
Characteristics
The earthquake began half an hour after sunrise, at 5:10 a.m. on 22 May 1766, which was the third day of the
Kurban Bairam.
The first shock, accompanied by a loud roar, lasted two minutes:
it was followed by a less intense shock lasting four minutes, and aftershocks continued for eight minutes.
In the following weeks there were also several aftershocks, and the duration of the whole sequence amounted to one year.
Mathematical models of this event using
Coulomb stress transfer Coulomb stress transfer is a Seismology, seismic-related geology, geological process of Stress (mechanics), stress changes to surrounding material caused by local discrete deformation events. Using mapped displacements of the Earth's surface during ...
are consistent with a fault rupture whose length ranges from .
The earthquake was felt as far away as
Aydın
Aydın ( ''EYE-din''; ; formerly named ''Güzelhisar; Greek: Τράλλεις)'' is a city in and the seat of Aydın Province in Turkey's Aegean Region. The city is located at the heart of the lower valley of Büyük Menderes River (ancient ...
,
Thessaloniki
Thessaloniki (; ), also known as Thessalonica (), Saloniki, Salonika, or Salonica (), is the second-largest city in Greece (with slightly over one million inhabitants in its Thessaloniki metropolitan area, metropolitan area) and the capital cit ...
, on
Mount Athos
Mount Athos (; ) is a mountain on the Athos peninsula in northeastern Greece directly on the Aegean Sea. It is an important center of Eastern Orthodoxy, Eastern Orthodox monasticism.
The mountain and most of the Athos peninsula are governed ...
,
Aytos
Aytos ( ), sometimes written Aitos and Ajtos, is a town located in eastern Bulgaria some 30 kilometers from the Bulgarian Black Sea Coast and belonging to the administrative boundaries of Burgas Province. It is the administrative centre of the ...
in eastern Bulgaria and along the west coast of the
Black Sea
The Black Sea is a marginal sea, marginal Mediterranean sea (oceanography), mediterranean sea lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bound ...
.
This earthquake was compared to
the catastrophic one in Lisbon, which occurred 11 years earlier.
Damage

The estimated area of significant damage (greater than the
MCS VII grade (Very Strong)) extends from
Bursa
Bursa () is a city in northwestern Turkey and the administrative center of Bursa Province. The fourth-most populous city in Turkey and second-most populous in the Marmara Region, Bursa is one of the industrial centers of the country. Most of ...
to
Küçükçekmece
Küçükçekmece (; meaning “small-drawer”, from much earlier ''Rhegion'' (Greek: Ρήγιον) and ''Küçükçökmece as “little breakdown''" or “''little depression''”, in more ancient times just as Bathonea), is a municipality and d ...
,
but destruction occurred from
Tekirdağ
Tekirdağ () is a city in northwestern Turkey. It is located on the north coast of the Sea of Marmara, in the region of East Thrace. The city forms the urban part of the Süleymanpaşa district, with a population of 186,421 in 2022.
Tekirdağ ...
and
Gelibolu
Gelibolu is a town in Çanakkale Province of the Marmara Region, located in Eastern Thrace in the European part of Turkey. It is located on the southern shore of the Gallipoli, peninsula named after it on the Dardanelles strait, away from Lapsek ...
to the west, İzmit to the east and
Edirne
Edirne (; ), historically known as Orestias, Adrianople, is a city in Turkey, in the northwestern part of the Edirne Province, province of Edirne in Eastern Thrace. Situated from the Greek and from the Bulgarian borders, Edirne was the second c ...
to the north.
The settlements on the Gulf of
Mudanya
Mudanya (also: Mudania; , ''ta Moudaniá''; the site of ancient Apamea Myrlea) is a municipality and Districts of Turkey, district of Bursa Province, Turkey. Its area is 369 km2, and its population is 108,011 (2022). It is located on the Gulf ...
also suffered damage,
while
Galata
Galata is the former name of the Karaköy neighbourhood in Istanbul, which is located at the northern shore of the Golden Horn. The district is connected to the historic Fatih district by several bridges that cross the Golden Horn, most nota ...
and
Büyükçekmece
Büyükçekmece, historically Athyras (Greek: Αθύρας) is a municipality and district of Istanbul Province, Turkey. Its area is 173 km2, and its population is 277,181 (2022). It is on the Sea of Marmara coast of the European side, west o ...
were severely damaged. In Constantinople the intensity of the earthquake was estimated between grade VII
and VIII-IX;
many houses and public buildings collapsed.
Furthermore, part of the underground water distribution system was destroyed;
the Ayvad dam, on the upper
Kâğıthane, was damaged, and in Istanbul the vault of an underground
cistern
A cistern (; , ; ) is a waterproof receptacle for holding liquids, usually water. Cisterns are often built to catch and store rainwater. To prevent leakage, the interior of the cistern is often lined with hydraulic plaster.
Cisterns are disti ...
subsided.
In Istanbul, most of the
mosque
A mosque ( ), also called a masjid ( ), is a place of worship for Muslims. The term usually refers to a covered building, but can be any place where Salah, Islamic prayers are performed; such as an outdoor courtyard.
Originally, mosques were si ...
s and churches were damaged, as was the
Topkapı Palace
The Topkapı Palace (; ), or the Seraglio, is a large museum and library in the east of the Fatih List of districts of Istanbul, district of Istanbul in Turkey. From the 1460s to the completion of Dolmabahçe Palace in 1856, it served as the ad ...
: the
sultan
Sultan (; ', ) is a position with several historical meanings. Originally, it was an Arabic abstract noun meaning "strength", "authority", "rulership", derived from the verbal noun ', meaning "authority" or "power". Later, it came to be use ...
had to live in temporary housing until his home was restored.
The panicking populace was unable to go back home, and people sheltered themselves in tents pitched in wide and open spaces.
Among the imperial mosques, the dome of
that of Bayezid was damaged, while the
minaret
A minaret is a type of tower typically built into or adjacent to mosques. Minarets are generally used to project the Muslim call to prayer (''adhan'') from a muezzin, but they also served as landmarks and symbols of Islam's presence. They can h ...
and the main dome of the
mosque of Mihrimah collapsed. The
Süleymaniye Mosque
The Süleymaniye Mosque (, ) is an Ottoman imperial mosque located on the Seven hills of Istanbul, Third Hill of Istanbul, Turkey. The mosque was commissioned by Suleiman the Magnificent () and designed by the imperial architect Mimar Sinan. An ...
was also damaged, while the
Fatih Mosque
The Fatih Mosque (, "Conqueror's Mosque" in English language, English) is an Ottoman Empire, Ottoman mosque off Fevzi Paşa Caddesi in the Fatih district of Istanbul, Turkey. The original mosque was constructed between 1463 and 1470 on the site ...
suffered the collapse of the minarets, the main dome and several secondary domes, and 100 students in the
Koran school of the ''
Külliye
A külliye () is a complex of buildings associated with Turkish architecture centered on a mosque and managed within a single institution, often based on a waqf (charitable foundation) and composed of a madrasa, a Dar al-Shifa (clinic), kitchens ...
'' died; so the complex had to be rebuilt.
The
Kariye Mosque was also seriously damaged, but the
mosque of Ayasofya survived instead almost unharmed.
The
castle of Yedikule, Eğrikapı,
Edirnekapı and the
city walls
A defensive wall is a fortification usually used to protect a city, town or other settlement from potential aggressors. The walls can range from simple palisades or earthworks to extensive military fortifications such as curtain walls with to ...
were also damaged, while there was damage to Galata and
Pera
Pera may refer to:
Places
* Pera (Beyoğlu), a district in Istanbul formerly called Pera, now called Beyoğlu
** Galata, a neighbourhood of Beyoğlu, often referred to as Pera in the past
* Pêra (Caparica), a Portuguese locality in the district o ...
and to the
Grand Bazaar.
At
Çatalca
Çatalca () is a municipality and Districts of Turkey, district of Istanbul Province, Istanbul Province, Turkey. Its area is 1142 km2, making it the largest district in Istanbul Province by area. Its population is 77,468 (2022). It is in Eas ...
and in the surrounding villages all the masonry buildings collapsed.
Since the earthquake struck the eastern part of the Sea of Marmara, serious damage was also recorded on the southern shore, from Mudanya to
Karamürsel
Karamürsel is a municipality and Districts of Turkey, district of Kocaeli Province, Turkey. Its area is 262 km2, and its population is 59,676 (2022). It is on the south coast of the Gulf of İzmit. Before its conquest by the Ottoman Empire, ...
,
and the tsunami waves made the ports unusable. The highest level of the
tsunami
A tsunami ( ; from , ) 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 underwater explosions (including detonations, ...
was observed in the
Bosphorus
The Bosporus or Bosphorus Strait ( ; , colloquially ) is a natural strait and an internationally significant waterway located in Istanbul, Turkey. The Bosporus connects the Black Sea to the Sea of Marmara and forms one of the continental bo ...
region.
Casualties
The number of deaths was estimated at 4,000,
of which 880 were in Istanbul.
August earthquake
In August of the same year, a magnitude 7.4 earthquake struck the
Dardanelles
The Dardanelles ( ; ; ), also known as the Strait of Gallipoli (after the Gallipoli peninsula) and in classical antiquity as the Hellespont ( ; ), is a narrow, natural strait and internationally significant waterway in northwestern Turkey th ...
region. On that occasion the damage in Istanbul was slight.
This earthquake killed more than 5,000 people.
References
Sources
*
{{DEFAULTSORT:Istanbul earthquake, 1766
1766 disasters
1766 in Asia
1766 in Europe
1766 in Ottoman Empire
1766 in science
1760s earthquakes
18th century in Istanbul
18th-century tsunamis
1766
Events
January–March
* January 1 – Charles Edward Stuart ("Bonnie Prince Charlie") becomes the new House of Stuart, Stuart claimant to the throne of Great Britain, as King Charles III, and figurehead for Jacobitism.
* Januar ...
Hagia Sophia
Sea of Marmara