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Beirut Conversion Quake

347/348/349 CE

by Jefferson Williams









Introduction & Summary

Beirut Conversion Quake Summary

Textual Evidence

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

Synopsis Historion by Cedrenus (aka George Kedrenus)

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