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Beirut Conversion Quake

347/348/349 CE

by Jefferson Williams








Introduction & Summary

Two late Byzantine writers (Theophanes and Cedrenus) report an earthquake causing extensive damage in Beirut and, by implication, the Lebanese littoral between 347 and 349 CE. According to both sources, most of the city collapsed. The dates supplied by the two sources likely constrain the date of this earthquake to between 25 Mar. 347 and 8 Sept. 349 CE. Grumel (1958) dated this earthquake to 348 CE. In some older catalogs, a possible tsunami is reported in association with this earthquake. A tsunami was not mentioned by either source. Although a tsunami was not mentioned, it is possible that this earthquake did generate a tsunami as the damage reports come from the coastal city of Beirut. Further details can be found in the Tsunamogenic Evidence section.

Textual Evidence

Text (with hotlink) Original Language Biographical Info Religion Date of Composition Location Composed Notes
Chronicle of Theophanes Greek
Biography

Orthodox (Byzantium) 810-814 CE Vicinity of Constantinople Theophanes (c. 758/60-817/8) wrote an earthquake where most of the city of Berytos in Phoenicia collapsed while supplying a wide range of inconsistent time markers which suggest the earthquake struck between 25 Mar. 347 and 8 Sept. 349 CE.
Synopsis Historion by Cedrenus Greek
Biography

Orthodox (Byzantium) 1050s CE Anatolia Cedrenus wrote about an earthquake which struck Beirut where most of the city collapsed. He dated the earthquake to the 12th year of the reign of Constantius II which equates to between 9 September 348 CE and 9 September 349 CE.
Text (with hotlink) Original Language Biographical Info Religion Date of Composition Location Composed Notes
Chronicle of Theophanes

Background and Biography

Background and Biography

Excerpts
English from Mango Scott (1997)

[AM 5840, AD 347/8]

Constantius, 12th year
Sabores, 46th year
Liberius, 3rd year
Eusebios, 3rd year
Cyril, 8th year
Athanasios, 19th year
Phlakitos, 5th year

ln this year most of the city of Berytos in Phoenicia collapsed during a severe earthquake. As a result, many pagans entered the Church professing to be Christians just like us. Thereupon some of them introduced an innovation and went forth after robbing, as it were, the Church of her usages. They appointed a place of prayer and received the throng into it, imitating all the customs of the Church and becoming very close to us (just as the heresy of the Samaritans [is close] to the Jews), while still living in the pagan fashion.||a
Footnotes

a [Hypoth. Arian] 23.

Chronology

A wide spread of dates arise from Theophanes entry where A.M.a5840 and the 12th year of Constantius reign are likely the most reliable. This places the date of the earthquake between 25 Mar. 347 and 8 Sept. 349 CE. Grumel (1958) dated this earthquake to 348 CE.
Year Reference Corrections Notes
25 Mar. 347 to 24 Mar. 348 CE A.M.a 5840 none
  • Calculated with CHRONOS
  • 1 September 347 CE to 31 August 348 CE is also possible
  • Mango, C. and R. Scott (1997) date A.M.a 5840 from 1 September 347 CE to 31 August 348 CE.
  • no correction required - not within the time span (A.M.a 6102-6206 or 6218-6265) when Theophanes' A.M.a are frequently a year too low.
9 Sept. 348 to 8 Sept. 349 CE Constantius, 12th year
1 Jan. 354 to 30 Dec. 355 CE Sabores, 46th year
  • Calculated with CHRONOS
  • Sabores (aka Shapur II) was crowned King in utero. Thus by some accounts, his reign started at his birth in 309 CE. He reached maturity at age 16.
17 May 354 to 20 June 355 CE Liberius, 3rd year
  • Calculated with CHRONOS
  • Liberius became the Pope of Rome on 17 May, 22 May or 21 June 352 CE
Eusebios, Bishop of Constantinople, 3rd year
end of 357 to end of 358 CE Cyril, 8th year
  • Calculated with CHRONOS
  • Cyril became the Bishop of Jerusalem around the end of 350 CE.
8 June 346 to 7 June 347 CE Athanasios, 19th year
  • Calculated with CHRONOS
  • Athanasios became the Pope of Alexandria around 8 June 328. His intermittent episcopacy spanned 45 years (c. 8 June 328 – 2 May 373), of which over 17 encompassed five exiles, when he was replaced on the order of four different Roman emperors.
1 Jan. 337 to 30 Dec. 339 CE Phlakitos, 5th year
Seismic Effects Locations Sources
Sources

Online Versions and Further Reading
References

Notes
Theophanes' Calendars

Synopsis Historion by Cedrenus (aka George Kedrenus)

Background and Biography

Background and Biography

Excerpts
English translated from Niebuhr (1838)

In the 12th year [of Constantius II's reign] there was a great earthquake in Berytus in Phoenicia, and most of the city collapsed.

Latin from Niebuhr (1838)

Duodecimo anno terrae motus maiorem Beryti (urbs est Phoeniciae) partem evertit,

Greek from Niebuhr (1838)

Τῷ (iB ἔτει σεισμὸς μέγας ἐγένετο ἐν Βηρυτῷ τῆς Φοινίκης, ὡς τὸ πλεῖον τῆς πόλεως πεσεῖν.

Greek and Latin from Niebuhr (1838) - embedded



Chronology

Like Theophanes, Cedrenus dates the earthquake to the 12th year of the reign of Constantius II which dates the earthquake to between 9 September 348 CE and 9 September 349 CE. Grumel (1958) dated this earthquake to 348 CE.
Year Reference Corrections Notes
9 Sept. 348 to 8 Sept. 349 CE Constantius, 12th year none
  • Calculated with CHRONOS
  • reign started 9 September 337 CE
Seismic Effects Locations Online Versions and Further Reading
References

Archeoseismic Evidence

Tsunamogenic Evidence

Location (with hotlink) Status Intensity Notes
Arwad Island possible to unlikely Several catalogs ( e.g. Ambraseys, 1962, Antonopoulos, 1979, Antonopoulos, 1980a, and Sbeinati et. al., 2005) consider the possibility that a tsunami was associated with The Beirut Conversion Quake of 347/348/349 CE. While this is valid speculation, none of the historical sources mention a tsunami. The way a tsunami entered these catalogs is likely via Sieberg (1932b) who mentioned damage on the Island of Arwad due to this earthquake.
348. Zers Arendes Beben an der syrischen kaste, wobei vor allein Berytus und Aradus (Ruad) litten

Translation : Earthquake on the Syrian Coast where Beirut and Arwad Island suffered.
The Island of Arwad is approximately 100 km. from Beirut. In the apparently larger 551 CE Beirut Quake, Sieberg (1932b) mentions widespread destruction in Beirut and that the earthquake was only felt in the Island of Arwad. He does not say it suffered. Based on this, if Sieberg (1932b) mentions suffering on the Island of Arwad due to the Beirut Conversion Quake, the suffering would likely be due to a tsunami rather than seismic shaking. Unfortunately, Sieberg (1932b) did not list his sources. As neither of the sources (Theophanes and Cedrenus) mention damage on the Island of Arwad, this tsunami report, though possible, is likely a false one. Salamon et. al. (2011) concurred that this tsunami report was probably false.
Location (with hotlink) Status Intensity Notes
Arwad Island



Paleoseismic Evidence

Location (with hotlink) Status Intensity Notes
Tabarja Benches possible Mw = ~7.5 Elias et al (2007) examined uplifted benches on the Lebanese coast between Sarafand and Tripolis; some in the vicinity of Tabarja (~20 km. NE of Beirut). They identified four uplifts from 3 or more [sizeable Mw = ~7.5] earthquakes in the past ca. 6-7 ka. They attributed the latest uplift (B1) to the 551 CE Beirut Quake while the earlier events (B2, B3, and B4) were no more precisely dated than between ~5000 BCE and 551 CE. Bench uplift on the earlier events (B2, B3, and B4) would likely have been due to uplift on the Mount Lebanon Thrust system - as was surmised for Event B1 and the 551 CE Beirut Quake.
al-Harif Syria possible ≥ 7
MW =  7.3 to 7.6		 Sbeinati et. al. (2010) report a seismic event X which they dated to 335 AD ± 175 years at a displaced aqueduct at al-Harif, Syria (close to Masyaf, Syria). The al-Harif aqueduct is 154 km. from Beirut.
Kazzab Trench possible ≥ 7 Daeron et al (2007) dated Event S3 to between 30 BCE and 469 CE and suggested the most likely causitive earthquake was the 347/348/349 CE Beirut Conversion Earthquake.
Bet Zayda possible to probable ≥ 7 In paleoseismic trenches just north of the Sea of Galilee (aka Lake Kinneret), Wechsler at al. (2014) identified 3 events which could fit this earthquake. When considering the context of all seismic events recorded at Bet Zayda, Event CH4-E2 (Modeled Age 269-329 CE) seems the most likely candidate. Wechsler et al (2014) noted that evidence for event CH4-E2 is weaker than that of some events.
Dead Sea - Seismite Types n/a n/a n/a
Dead Sea - En Feshka possible to unlikely 7.9 - 8.8       Although Kagan et al (2011) assigned a 1 cm. intraclast breccia (Type 4 Seismite) at 228.0 cm. depth to a 349 CE date, this is on the edge of the modeled ages for this seismite (± 1σ - 430 CE ± 58, ± 2σ - 422 CE ± 126). Further, due to the distance involved (En Feshka is 240 km. from Beirut), this seems like an unlikely match. The 228 cm. seismite and another seismite at 220 cm. depth seem more likely to have been generated during one of the Cyril Quakes and the Monaxius and Plinta Quake.
Dead Sea - En Gedi unlikely - no evidence Migowski et. al. (2004) did not assign any seismites to any dates around 347-349 CE.
Dead Sea - Nahal Ze 'elim unlikely - no evidence Kagan et al (2011) did not assign any seismites at site ZA-2 to any dates around 347-349 CE.
Location (with hotlink) Status Intensity Notes
Tabarja Benches

Elias et al (2007) examined uplifted benches on the Lebanese coast between Sarafand and Tripolis; some in the vicinity of Tabarja (~20 km. NE of Beirut). They identified four uplifts from 3 or more [sizeable Mw = ~7.5] earthquakes in the past ca. 6-7 ka. They attributed the latest uplift (B1) to the 551 CE Beirut Quake while the earlier events (B2, B3, and B4) were no more precisely dated than between ~5000 BCE and 551 CE. Bench uplift on the earlier events (B2, B3, and B4) would likely have been due to uplift on the Mount Lebanon Thrust system - as was surmised for Event B1 and the 551 CE Beirut Quake.



Displaced Aqueduct at al Harif, Syria

Sbeinati et. al. (2010) report a seismic event X which they dated to 335 AD +/- 175 years at a displaced aqueduct at al-Harif, Syria (close to Masyaf, Syria). The al-Harif aqueduct is 154 km. from Beirut.



Kazzab Trench

Daeron et al (2007) dated Event S3 to between 30 BCE and 469 CE and suggested the most likely causitive earthquake was the 347/348/349 CE Beirut Conversion Earthquake.



Bet Zayda (aka Beteiha)

In paleoseismic trenches just north of the Sea of Galilee (aka Lake Kinneret), Wechsler at al. (2014) identified 3 events which could fit this earthquake. When considering the context of all seismic events recorded at Bet Zayda, Event CH4-E2 (Modeled Age 269-329 CE) seems the most likely candidate. Wechsler et al (2014) noted that evidence for event CH4-E2 is weaker than that of some events.



Dead Sea - Seismite Types



Dead Sea - En Feshka

Although Kagan et al (2011) assigned a 1 cm. intraclast breccia (Type 4 Seismite) at 228.0 cm. depth to a 349 CE date, this is on the edge of the modeled ages for this seismite (± 1σ - 430 CE ± 58, ± 2σ - 422 CE ± 126). Further, due to the distance involved (En Feshka is 240 km. from Beirut), this seems like an unlikely match. The 228 cm. seismite and another seismite at 220 cm. depth seem more likely to have been generated during one of the Cyril Quakes and the Monaxius and Plinta Quake. Modeled ages from Table 3 are presented below.



Dead Sea - En Gedi

Migowski et. al. (2004) did not assign any seismites to any dates around 347-349 CE.



Dead Sea - Nahal Ze 'elim

Kagan et al (2011) did not assign any seismites at site ZA-2 to any dates around 347-349 CE.



Notes

Paleoclimate - Droughts

Footnotes

References