• The first to second century A.D. basal rubble unit (L4) was found on the carbonate cemented sandstone bedrock (locally known as kurkar) and was characteristic of a high-energy water deposit (Fig. 2). The rubble was framework supported with little surrounding matrix and composed mainly of cobble-sized material, which was well rounded, heavily encrusted (e.g., bryozoans, calcareous algae), and bored (Lithophaga lithophaga, Cliona) on its upper surface. The rubble had variable lithologies including basalts, gabbros, and dolomites, all of which are absent on the Israeli coastal plain and were likely transported to the site as ship ballast (probably from Cyprus). The surrounding matrix was composed of shell material (mainly Glycymeris insubricus), pebbles, and coarse sand. The pottery sherds found in this unit were well rounded, encrusted, and dated to the first to second century A.D. The date for this unit and its sedimentological characters clearly records the existence of high-energy conditions within the inner harbor about 100-200 yr after the harbor was built. This evidence of high-energy water conditions indicates that the outer harbor breakwaters must have been severely degraded by this time to allow waves to penetrate the inner confines of the harbor (Fig. 3, A and B).
  
  Indication of the rapid destruction of the outer harbor breakwaters toward the end of the first century A.D. is derived from additional data recovered from the outer harbor. In the 1993 season, a late first century A.D. shipwreck was found on the southern submerged breakwater. The merchant ship was carrying lead ingots that were narrowly dated to A.D. 83-96 based on the inscription "IMP.DOMIT.CAESARIS.AUG.GER." which refers to the Roman Emperor Domitianus (Raban, 1999). The wreck was positioned on the harbor breakwater, indicating that this portion of the structure must have been submerged to allow a ship to run-up and founder on top (Raban, 1999; Fig. 3B). Because Josephus praised the harbor in grand terms and referred to it as a functioning entity around A.D. 75-79, and yet portions of the breakwater were submerged by A.D. 83-96, we conclude that there was a rapid deterioration and submergence of the harbor, probably through seismic activity. - Reinhardt and Raban (1999)


• The submergence of the outer harbor break-waters at the end of the first century A.D. could have also been due to seismic liquefaction of the sediment. Excavations have shown that the harbor breakwaters were constructed on well-sorted sand that could have undergone liquefaction with seismic activity. In many instances the caissons are tilted (15°-20° from horizontal; Raban et al., 1999a) and at different elevations, which could be due to differential settling (area K; Fig. 1). However, the tilting could also be due to undercutting by current scour from large-scale storms (or tsunamis) and not exclusively seismic activity. Our data from the inner harbor cannot definitively ascribe the destruction of the harbor at the end of the first century A.D. to a seismic event, although some of the data support this conclusion. However, regardless of the exact mechanism, our sedimentological evidence from the inner harbor and the remains of the late first century A.D. shipwreck indicate that the submergence of the outer breakwater occurred early in the life of the harbor and was more rapid and extensive than previously thought. - Reinhardt and Raban (1999)

• Although Goodman-Tchernov and Austin (2015) and earlier researchers associated a 1st - 2nd century CE tsunamite deposit from offshore Caesarea with the Trajan quake of ~115 CE, this association is unlikely. Salamon et al (2011) noted that the presence of a tsunami far south of the supposed epicenter of the Trajan Quake does not fit the usual pattern of tsunamis on the Israeli coast where most tsunamis which hit the coast were generated by ruptures more or less opposite to the coast (e.g. from the Cypriot and Hellenic Arcs). While Salamon et al (2011) suggested a storm surge as a possibility, the work of Goodman-Tchernov and Austin (2015) and earlier publications appears to preclude this as they used a host of indicators to seperate storm surge deposits from tsunamite deposits. I propose that an offshore shelf collapse potentially due to the Incense Road Earthquake of the early 2nd century CE as a likely cause.


• Goodman-Tchernov and Austin (2015) examined and dated cores taken seaward of the harbor and identified 2 tsunamite deposits (see Tsunamogenic Evidence) including one which dates to to the 1st-2nd century CE. Although, it is tempting to correlate the 1st-2nd century CE tsunamite deposits of Goodman-Tchernov and Austin (2015) to the L4 destruction phase identified in the harbor ( Reinhardt and Raban, 1999), the chronologies presented by Goodman-Tchernov and Austin (2015) suffer from some imprecision due to the usual paucity of dating material that one encounters with cores. Further, the harbor subsidence and breakwater degradation dated by Reinhardt and Raban (1999) may not have been caused by seismic activity. If it was related to seismic activity, the early 2nd century CE Incense Road Quake is a better candidate than the 115 CE Trajan Quake because it would have produced higher intensities in Caesarea.


• 4.5.2. Sedimentological Findings at Sea Presented as Indicators of a Tsunami
  
  The core issue in tsunami sedimentology is to distinguish tsunami deposits from beach or storm deposits. Marine fauna and marine deposits found in low-lying, lagoonal water bodies near the coast are often used as paleo tsunami indicators, and so is the presence of large boulders on a rocky coast, away from the sea [42,83,84]. Identifying offshore tsunami deposits is more challenging. It has been less practiced, as there are very few analogies for comparison and it is hard to distinguish them from storm deposits [10,42,83]. A comprehensive study conducted by Mariner et al. [84] analyzed hundreds of published records of tsunami events in the Mediterranean and proposed that 90% of them are problematic and need to be re-examined.
  
  4.5.3. Outside the Harbor
  
  At a water depth of 10–12 m offshore, Reinhardt et al. (area W, [42]) identified beds of small angular shell fragments and potsherds dated from the 1st century BCE to the 1st century CE that were overlain by a layer of convex-up-oriented disarticulated bivalve shells. Relying on the fragmentation patterns and stratigraphy of the shells, the authors assumed that these shells could be related to the 115 CE tsunami deposits. Reinhardt et al. [42] also reported on the presence of articulated Glycymeris shells in the tsunami deposit, and suggested that these shells indicate transport from the deeper shelf, as the shallowest habitation depth for these bivalves is 18 m. However, no evidence for the presence of such articulated Glycymeris shells in the discussed deposits have ever been presented or published. Furthermore, Meinis et al. [85] noted that Glycymeris sp. (especially G. insubrica or violescens) were very common along the Israeli coast over long periods. They existed at different depths in a coastal environment (e.g., 8–16 m depth) and even at 200 m water depth. In the Adriatic Sea, their habitat was reported to be at a water depth of 2–40 m [86]. Moreover, Reinhardt et al. [42] give no explanation of how these articulated mollusks survived what they describe as the “ . . . intense wave turbulence, shell-to-shell impacts, and shells striking the harbor moles or bedrock under high wave energy, as generated by a tsunami”. Given the above, there is nothing special in finding G. insubrica in sea bed sediments which are shallower than 18 m. The existence of articulated Glycymeris bivalves in the discased Caesarea deposits is yet to be proven, while the preservation of such articulated shells under a catastrophic tsunami that was assumed to destroy the Roman Harbor, is still to be explained.
  
  As noted above, it is difficult to distinguish between tsunami and storm deposits [83,84,87,88]. Sakuna et al. [89] noted the difficulty in identifying the shallow-marine tsunami deposits associated with the 2004 Indian Ocean tsunami based on sedimentological evidence. Tamura et al. [10], who study the 2011 tsunami in Japan, concluded that this tsunami (“one of the largest modern tsunamis in the last 1200 years”) did not produce distinct sedimentary records in Sendai Bay. He also stated that there are no established unequivocal criteria for identifying shallow marine tsunami deposits and that it is impossible to identify the associated deposits at sea, since they are not preserved and might have been mixed by storms [10]. Their results agree with the suggestions of Weiss and Bahlburg [90] that the offshore tsunami deposits are unlikely to be preserved at depths shallower than 65 m. In this regard, the deposits identified by Reinhardt et al. [42] as the result of the 115 tsunami that is supposed to have destroyed the harbor, are questionable, as are the three reflected sub-bottom layers identified by Goodman-Tchernov and Austin [9] as tsunami features. - Galili et al (2021:16-17,20)

• The first to second century A.D. basal rubble unit (L4) was found on the carbonate cemented sandstone bedrock (locally known as kurkar) and was characteristic of a high-energy water deposit (Fig. 2). The rubble was framework supported with little surrounding matrix and composed mainly of cobble-sized material, which was well rounded, heavily encrusted (e.g., bryozoans, calcareous algae), and bored (Lithophaga lithophaga, Cliona) on its upper surface. The rubble had variable lithologies including basalts, gabbros, and dolomites, all of which are absent on the Israeli coastal plain and were likely transported to the site as ship ballast (probably from Cyprus). The surrounding matrix was composed of shell material (mainly Glycymeris insubricus), pebbles, and coarse sand. The pottery sherds found in this unit were well rounded, encrusted, and dated to the first to second century A.D. The date for this unit and its sedimentological characters clearly records the existence of high-energy conditions within the inner harbor about 100-200 yr after the harbor was built. This evidence of high-energy water conditions indicates that the outer harbor breakwaters must have been severely degraded by this time to allow waves to penetrate the inner confines of the harbor (Fig. 3, A and B).
  
  Indication of the rapid destruction of the outer harbor breakwaters toward the end of the first century A.D. is derived from additional data recovered from the outer harbor. In the 1993 season, a late first century A.D. shipwreck was found on the southern submerged breakwater. The merchant ship was carrying lead ingots that were narrowly dated to A.D. 83-96 based on the inscription "IMP.DOMIT.CAESARIS.AUG.GER." which refers to the Roman Emperor Domitianus (Raban, 1999). The wreck was positioned on the harbor breakwater, indicating that this portion of the structure must have been submerged to allow a ship to run-up and founder on top (Raban, 1999; Fig. 3B). Because Josephus praised the harbor in grand terms and referred to it as a functioning entity around A.D. 75-79, and yet portions of the breakwater were submerged by A.D. 83-96, we conclude that there was a rapid deterioration and submergence of the harbor, probably through seismic activity. - Reinhardt and Raban (1999)


• The submergence of the outer harbor break-waters at the end of the first century A.D. could have also been due to seismic liquefaction of the sediment. Excavations have shown that the harbor breakwaters were constructed on well-sorted sand that could have undergone liquefaction with seismic activity. In many instances the caissons are tilted (15°-20° from horizontal; Raban et al., 1999a) and at different elevations, which could be due to differential settling (area K; Fig. 1). However, the tilting could also be due to undercutting by current scour from large-scale storms (or tsunamis) and not exclusively seismic activity. Our data from the inner harbor cannot definitively ascribe the destruction of the harbor at the end of the first century A.D. to a seismic event, although some of the data support this conclusion. However, regardless of the exact mechanism, our sedimentological evidence from the inner harbor and the remains of the late first century A.D. shipwreck indicate that the submergence of the outer breakwater occurred early in the life of the harbor and was more rapid and extensive than previously thought. - Reinhardt and Raban (1999)


• 4.5.4. Tsunami Deposits in the Eastern (Inner) Basin
  
  Excavations in the eastern basin [40] yielded a thin layer of sediments from the 1st to 2nd centuries CE, overlain by a deposit of mixed sediments. They determined that in the 1st century, and evidently up to the 3rd century CE, the prevailing conditions in the eastern basin were of a brackish body of water with good circulation. Thus, the inner harbor seems to have been in use after 115 CE. The mixed sediment deposits discovered in the eastern basin was attributed by Reinhardt and Raban [40] to cleaning and deepening of the harbor in early periods. The proposed main mechanisms for the destruction of the harbor in the study by Reinhardt and Raban [40] were the seismic and tectonic scenarios. Later, however, after reassessing the finds in light of the available new studies on tsunamis, the tectonic and seismic scenarios, as well as the dredging deposit hypothesis, gave way to the 115 CE tsunami scenario [42].
  
  - Galili et al (2021:16-17,20)

• At the very deepest spot where the airlift penetrated, beneath huge stone blocks which teetered precariously above the divers' heads, was uncovered a large wooden beam. Beneath its protective cover the divers found the only whole amphora of our dig. This proved to be a second century Roman vessel. The fact that it was found under the tumbled beam and masonry would indicate that these things were catapulted into the sea at the same time. Since there is a strong earthquake recorded in the area of Caesarea in the year A.D. 130 [JW: this refers to the Eusebius Mystery Quake - could also be Incense Road Quake], it may possibly be that the harbor installations of Herod were destroyed at that time. - Fritsch and Ben-Dor (1961)

• Goodman-Tchernov et al (2009) identified tsunamites in cores taken immediately offshore of the harbor of Caesarea which Goodman-Tchenov and Austin (2015) dated to the 5th - 8th century CE and associated with tsunamis generated by the Beirut Quake of 551 CE and one of the Sabbatical Year Quakes. Although earlier works assigned this 5th - 8th century tsunamite deposit solely to the Beirut Quake of 551 CE, later revisions assigned this offshore deposit mostly to one of the Sabbatical Year Quakes with the suggestion that the Sabbatical Year Quake tsunami deposit contained some reworked tsunamites from the Beirut Quake of 551 CE. The revision may be based on the analysis of re-interpreted landward tsunami deposits (see Fig. 14 above from Galili et. al., 2021) which were dated by Dey et al (2014) to around the time of the Sabbatical Year Quakes. The chronology of the cores was determined using an assemblage of ceramic finds, radiocarbon, and optically stimulated luminescence (OSL) dating. Multiple indicators were used to distinguish tsunami deposits from storm deposits. Particle size distributions were shown to be particularly helpful and reliable. Tsunami horizons were characterized by a wider range of grain sizes and poorer sorting.
  
  Although efforts to distinguish two tsunami events in the 5th-8th century tsunamogenic deposit by coring in deeper water where an intervening layer, for example, might be present are reported in publications such as Dey et al (2014), this has not yet, to my knowledge, been accomplished. Tsunamogenic evidence for for an event in the mid 8th century CE (e.g. the Holy Desert Quake of the Sabbatical Year Quakes) is better supported than for the 551 CE Beirut Quake although it is possible that both earthquakes generated a tsunami which struck Caesarea.


• Tyuleneva et. al. (2017) identified what appears to be the same tsunamite in a core (Jisr al-Zarka 6) taken offshore of nearby Jisr al-Zakra. This core was located ~1.5-4.5 km. north of the Caesarea cores. The tsunamite deposit from Jisr al-Zarka was more tightly dated to 658-781 CE (1292-1169 Cal BP) – within the time window for the Holy Desert Quake of the Sabbatical Year Earthquake sequence.

• Goodman-Tchernov and Austin (2015) produced a description of a potential tsunami deposit in the shallow intermediate harbor.

  In excavations of the shallow intermediate harbor (TN area, Fig. 1C; Reinhardt and Raban, 2008:155-182 ), there is an extensive deposit of mixed (Early Islamic- Byzantine–4th to 8th century CE) refuse, ranging from high-value intricate items of varying erosion state and exposure—suggesting broad mixing of typical harbor refuse (e.g., broken amphora/pots) and newly introduced, undamaged domestic wares and personal items (e.g., intricate hair combs, fine sections of Islamic coins, statuette, a satchel of copper coins). Unlike other harbor deposits, these materials are of broad origin (domestic, commercial, religious), value range and preservation state, suggesting the kind of non-deliberate and rapid burial a tsunami event would produce. In addition, because the ages of the ceramics found in this excavation range from early Islamic to late Byzantine (6th through 8th centuries CE), no distinctive stratigraphy offshore today separates what may have been two distinct tsunami events.

  Dey and Goodman-Tchernov (2010:278) reported on potential 6th century CE tsunami deposits in the inner and outer harbors.

  The inner harbour was blanketed with a thick deposit of heterogeneous rubble, including bones and other organic remains, pottery, and architectural materials.⁶³ Meanwhile, in the outer harbour, a powerful scouring effect mixed materials datable from the 1st c. B.C. to the 6th c. A.D. into a single, undifferentiated mass, further undermined the breakwaters, and cut a trench into the channel between the outer moles.⁶⁴ The signs from both the inner and outer harbour are dramatic enough to have led previous commentators already to propose the tsunami of 551 as a possible cause.⁶⁵
  
  

  Footnotes

  [63] Raban 1996, 662; Yule and Barham 1999, 277-78; Reinhardt and Raban 2008, 177-78.
  
  [64] Reinhardt and Raban 2008, 178-79.
  
  [65] See, e.g., Raban 1996, 662; Yule and Barham 1999, 277-78; Reinhardt and Raban 2008, 177-78.
  
  

Site LL is located just north of Caesarea's inner harbour. Ad et al (2018) excavated the site which was in use from the Herodian period to the Umayyad period. A storage structure (aka "the warehouse") was identified in the western part of the site which appears to have been constructed in Herodian times and remained in use, as it underwent changes, until the middle of the Umayyad period (~700 CE). After the Islamic conquest of Caesarea (640 CE), rooms were partitioned, floors were raised, construction was added and some of the openings were sealed. Ceramics indicate that the site was abandoned at the end of the 7th century CE after which it suffered two major destruction events before re-occupation occurred in the mid 8th century CE in what was interpreted as Abbasid Strata V (the Abbasid Caliphate began ruling in 750 CE). During the renewed Abbasid occupation, destruction debris were preserved as the builders preferred to level the area and build above the destruction layer(s). The destruction events within Stratum VI (Umayyad) appear to be an earthquake and a tsunami; both likely a result of the the Holy Desert Quake of the Sabbatical Year Quake sequence.

Ad et al (2018) report that during the earthquake event several ceilings collapsed inward, and there was evidence of a fire in the eastern warehouse.¹ In the collapse in the corridor, the original order of the courses of the wall or vault could be clearly identified (Fig. 8) adding confidence to a seismic interpretation. During the subsequent tsunami event, a layer of sand and collapsed building stones had accumulated to a height of more than 2 m in Rooms 8–11 in the western warehouse and to a height of 1.5 m in Rooms 12–14 and the corridor of the eastern warehouse. Everhardt et. al. (2023) further examined the destruction deposits by taking cores and radiocarbon samples as well as examining burn evidence and a baulk inside the collapsed corridor.

The cores (C1 and C2) were taken in the collapsed corridor after the Abbasid floor was removed, thus sampling the destruction deposits. See Fig. 1E for location of the cores (and southern baulk) and Fig. 3 for photos and descriptions of the cores and the southern baulk. A ~20 mg. charcoal sample from the top 3 cm of sediment in the Umayyad archaeological fill and one untreated sample of various organic material (~20 mg) from the top 5 cm of the same layer in core C1, as close as possible to the contact with the lower anomalous deposit, were collected for radiocarbon dating. Everhardt et. al. (2023:14-15) report that radiocarbon dates of charcoal and organic material from the upper contact of the Umayyad archaeological deposit (Unit C) range from 605 to 779 CE² which is in agreement with the phasing of Ad et al (2018) and compatible with destruction layers that were deposited in 749 CE.

Cores C1 and C2 were sampled and analyzed for grain size distribution, foraminiferal assemblage, total organic carbon (TOC), and Inorganic Carbon (IC). An additional 13 surface surface samples, including from storm surge deposits, were also collected, analyzed, and compared with the analysis of the Cores and Southern Baulk in order to help distinguish if a tsunami deposit was indicated in the cores and baulk. Portable-Optically Stimulated Luminescence (P-OSL) dating was also performed on the cores. Four sedimentary units (A-D) were identified in the two cores are were described as follows :

• In addition, there appears to be evidence of landward tsunami deposits. After the Muslim conquest in the 7th century, Caesarea depopulated. In the late 7th or early 8th century CE, the coastal strip south of where the Crusaders would later build their fortifications was transformed into lush terraced gardens irrigated by wells and cisterns ( Dey et al, 2014). Marine layers found on top of these gardens included Glycymeris, a non-edible deeper water bivalve. Atop the marine layer was, in some areas, a burial ground with a funerary inscription providing a terminus ante quem of 870 CE. A terminus post quem of c. 500 came from a reflecting pool fronting the Temple platform and overlain by the marine layer. Dey et al (2014) suggest that the most likely explanation for the transformation from gardens to burial ground was an intervening episode of tsunamogenic destruction. They discussed the potential landward tsunamogenic deposit as follows:

  The most substantial strata attributable to a marine inundation of mid-8th-c. date appeared in the SW sector, along the coastal strip south of the Crusader fortifications. Extensive tracts of these deposits between the temple platform and the theater, a shore-parallel distance of nearly 800 m, were uncovered (and removed, usually mechanically) in the 1970s and early 1980s under the auspices of the Joint Expedition (JECM). The bulk of the deposits lay in a shallow depression situated c.10 m above mean sea-level (MSL) and separated from the sea by a low ridge 15 m above MSL. From the landward side of the ridge, beginning c.50 m from the shore, these marine layers stretched inland as far as 300 m from the sea. ¹⁴ They comprised two distinct, superimposed sequences, each consisting of a thick, lower layer of densely-bedded (and in some cases imbricated) shells, rubble and sherds up to 1.5 m thick, topped by a dark, silty layer 20-40 cm thick. Datable materials in the second, upper sequence placed its formation around the 14th c. ¹⁵ In the lower sequence, dated by the excavators approximately to the 8th c. on the basis of finds, numerous disarticulated human remains turned up, as well as at least one complete skeleton in Area C, interbedded with the surrounding strata of shells and silt. ¹⁶ Like the rest of the materials, this corpse was probably deposited by a (cataclysmic) natural event. As D. Neev and K. Emery indicated in their report, there were no signs of a man-made grave, and the surrounding horizontal strata were uninterrupted above and below the skeleton; such 'culturally non-appropriate burials' are now recognized as a typical feature of tsunami deposits.¹⁷ The most likely scenario would have corpses deposited by the retreating waters of the tsunami and immediately covered with more detritus, keeping the articulated skeleton undisturbed by scavenging animals or human intervention.



• Excavations carried out on the coast of Caesarea yielded deposits which were associated with 6th and 8th century CE tsunami events (Figure 14) - Galili et al (2021:16-17,20)

• At Caesarea, the best evidence of destruction attributable to the 749 earthquake comes from Area TPS, on the S side of the Temple Platform, where a thick layer of debris marks the end of the Umayyad occupation of the Late Byzantine bath complex, which was subsequently mulled and built over in the later 8th century - see Raban and Yankelevitz (2008:81) and Arnon (2008:85). Another probable effect of the earthquake was the collapse of the octagonal church on the platform - see Holum et al (2008:30-31). - Dey et al (2014)

• The first to second century A.D. basal rubble unit (L4) was found on the carbonate cemented sandstone bedrock (locally known as kurkar) and was characteristic of a high-energy water deposit (Fig. 2). The rubble was framework supported with little surrounding matrix and composed mainly of cobble-sized material, which was well rounded, heavily encrusted (e.g., bryozoans, calcareous algae), and bored (Lithophaga lithophaga, Cliona) on its upper surface. The rubble had variable lithologies including basalts, gabbros, and dolomites, all of which are absent on the Israeli coastal plain and were likely transported to the site as ship ballast (probably from Cyprus). The surrounding matrix was composed of shell material (mainly Glycymeris insubricus), pebbles, and coarse sand. The pottery sherds found in this unit were well rounded, encrusted, and dated to the first to second century A.D. The date for this unit and its sedimentological characters clearly records the existence of high-energy conditions within the inner harbor about 100-200 yr after the harbor was built. This evidence of high-energy water conditions indicates that the outer harbor breakwaters must have been severely degraded by this time to allow waves to penetrate the inner confines of the harbor (Fig. 3, A and B).
  
  Indication of the rapid destruction of the outer harbor breakwaters toward the end of the first century A.D. is derived from additional data recovered from the outer harbor. In the 1993 season, a late first century A.D. shipwreck was found on the southern submerged breakwater. The merchant ship was carrying lead ingots that were narrowly dated to A.D. 83-96 based on the inscription "IMP.DOMIT.CAESARIS.AUG.GER." which refers to the Roman Emperor Domitianus (Raban, 1999). The wreck was positioned on the harbor breakwater, indicating that this portion of the structure must have been submerged to allow a ship to run-up and founder on top (Raban, 1999; Fig. 3B). Because Josephus praised the harbor in grand terms and referred to it as a functioning entity around A.D. 75-79, and yet portions of the breakwater were submerged by A.D. 83-96, we conclude that there was a rapid deterioration and submergence of the harbor, probably through seismic activity. - Reinhardt and Raban (1999)


• The submergence of the outer harbor break-waters at the end of the first century A.D. could have also been due to seismic liquefaction of the sediment. Excavations have shown that the harbor breakwaters were constructed on well-sorted sand that could have undergone liquefaction with seismic activity. In many instances the caissons are tilted (15°-20° from horizontal; Raban et al., 1999a) and at different elevations, which could be due to differential settling (area K; Fig. 1). However, the tilting could also be due to undercutting by current scour from large-scale storms (or tsunamis) and not exclusively seismic activity. Our data from the inner harbor cannot definitively ascribe the destruction of the harbor at the end of the first century A.D. to a seismic event, although some of the data support this conclusion. However, regardless of the exact mechanism, our sedimentological evidence from the inner harbor and the remains of the late first century A.D. shipwreck indicate that the submergence of the outer breakwater occurred early in the life of the harbor and was more rapid and extensive than previously thought. - Reinhardt and Raban (1999)

• Although Goodman-Tchernov and Austin (2015) and earlier researchers associated a 1st - 2nd century CE tsunamite deposit from offshore Caesarea with the Trajan quake of ~115 CE, this association is unlikely. Salamon et al (2011) noted that the presence of a tsunami far south of the supposed epicenter of the Trajan Quake does not fit the usual pattern of tsunamis on the Israeli coast where most tsunamis which hit the coast were generated by ruptures more or less opposite to the coast (e.g. from the Cypriot and Hellenic Arcs). While Salamon et al (2011) suggested a storm surge as a possibility, the work of Goodman-Tchernov and Austin (2015) and earlier publications appears to preclude this as they used a host of indicators to seperate storm surge deposits from tsunamite deposits. I propose that an offshore shelf collapse potentially due to the Incense Road Earthquake of the early 2nd century CE as a likely cause.


• Goodman-Tchernov and Austin (2015) examined and dated cores taken seaward of the harbor and identified 2 tsunamite deposits (see Tsunamogenic Evidence) including one which dates to to the 1st-2nd century CE. Although, it is tempting to correlate the 1st-2nd century CE tsunamite deposits of Goodman-Tchernov and Austin (2015) to the L4 destruction phase identified in the harbor ( Reinhardt and Raban, 1999), the chronologies presented by Goodman-Tchernov and Austin (2015) suffer from some imprecision due to the usual paucity of dating material that one encounters with cores. Further, the harbor subsidence and breakwater degradation dated by Reinhardt and Raban (1999) may not have been caused by seismic activity. If it was related to seismic activity, the early 2nd century CE Incense Road Quake is a better candidate than the 115 CE Trajan Quake because it would have produced higher intensities in Caesarea.


• 4.5.2. Sedimentological Findings at Sea Presented as Indicators of a Tsunami
  
  The core issue in tsunami sedimentology is to distinguish tsunami deposits from beach or storm deposits. Marine fauna and marine deposits found in low-lying, lagoonal water bodies near the coast are often used as paleo tsunami indicators, and so is the presence of large boulders on a rocky coast, away from the sea [42,83,84]. Identifying offshore tsunami deposits is more challenging. It has been less practiced, as there are very few analogies for comparison and it is hard to distinguish them from storm deposits [10,42,83]. A comprehensive study conducted by Mariner et al. [84] analyzed hundreds of published records of tsunami events in the Mediterranean and proposed that 90% of them are problematic and need to be re-examined.
  
  4.5.3. Outside the Harbor
  
  At a water depth of 10–12 m offshore, Reinhardt et al. (area W, [42]) identified beds of small angular shell fragments and potsherds dated from the 1st century BCE to the 1st century CE that were overlain by a layer of convex-up-oriented disarticulated bivalve shells. Relying on the fragmentation patterns and stratigraphy of the shells, the authors assumed that these shells could be related to the 115 CE tsunami deposits. Reinhardt et al. [42] also reported on the presence of articulated Glycymeris shells in the tsunami deposit, and suggested that these shells indicate transport from the deeper shelf, as the shallowest habitation depth for these bivalves is 18 m. However, no evidence for the presence of such articulated Glycymeris shells in the discussed deposits have ever been presented or published. Furthermore, Meinis et al. [85] noted that Glycymeris sp. (especially G. insubrica or violescens) were very common along the Israeli coast over long periods. They existed at different depths in a coastal environment (e.g., 8–16 m depth) and even at 200 m water depth. In the Adriatic Sea, their habitat was reported to be at a water depth of 2–40 m [86]. Moreover, Reinhardt et al. [42] give no explanation of how these articulated mollusks survived what they describe as the “ . . . intense wave turbulence, shell-to-shell impacts, and shells striking the harbor moles or bedrock under high wave energy, as generated by a tsunami”. Given the above, there is nothing special in finding G. insubrica in sea bed sediments which are shallower than 18 m. The existence of articulated Glycymeris bivalves in the discased Caesarea deposits is yet to be proven, while the preservation of such articulated shells under a catastrophic tsunami that was assumed to destroy the Roman Harbor, is still to be explained.
  
  As noted above, it is difficult to distinguish between tsunami and storm deposits [83,84,87,88]. Sakuna et al. [89] noted the difficulty in identifying the shallow-marine tsunami deposits associated with the 2004 Indian Ocean tsunami based on sedimentological evidence. Tamura et al. [10], who study the 2011 tsunami in Japan, concluded that this tsunami (“one of the largest modern tsunamis in the last 1200 years”) did not produce distinct sedimentary records in Sendai Bay. He also stated that there are no established unequivocal criteria for identifying shallow marine tsunami deposits and that it is impossible to identify the associated deposits at sea, since they are not preserved and might have been mixed by storms [10]. Their results agree with the suggestions of Weiss and Bahlburg [90] that the offshore tsunami deposits are unlikely to be preserved at depths shallower than 65 m. In this regard, the deposits identified by Reinhardt et al. [42] as the result of the 115 tsunami that is supposed to have destroyed the harbor, are questionable, as are the three reflected sub-bottom layers identified by Goodman-Tchernov and Austin [9] as tsunami features. - Galili et al (2021:16-17,20)

• The first to second century A.D. basal rubble unit (L4) was found on the carbonate cemented sandstone bedrock (locally known as kurkar) and was characteristic of a high-energy water deposit (Fig. 2). The rubble was framework supported with little surrounding matrix and composed mainly of cobble-sized material, which was well rounded, heavily encrusted (e.g., bryozoans, calcareous algae), and bored (Lithophaga lithophaga, Cliona) on its upper surface. The rubble had variable lithologies including basalts, gabbros, and dolomites, all of which are absent on the Israeli coastal plain and were likely transported to the site as ship ballast (probably from Cyprus). The surrounding matrix was composed of shell material (mainly Glycymeris insubricus), pebbles, and coarse sand. The pottery sherds found in this unit were well rounded, encrusted, and dated to the first to second century A.D. The date for this unit and its sedimentological characters clearly records the existence of high-energy conditions within the inner harbor about 100-200 yr after the harbor was built. This evidence of high-energy water conditions indicates that the outer harbor breakwaters must have been severely degraded by this time to allow waves to penetrate the inner confines of the harbor (Fig. 3, A and B).
  
  Indication of the rapid destruction of the outer harbor breakwaters toward the end of the first century A.D. is derived from additional data recovered from the outer harbor. In the 1993 season, a late first century A.D. shipwreck was found on the southern submerged breakwater. The merchant ship was carrying lead ingots that were narrowly dated to A.D. 83-96 based on the inscription "IMP.DOMIT.CAESARIS.AUG.GER." which refers to the Roman Emperor Domitianus (Raban, 1999). The wreck was positioned on the harbor breakwater, indicating that this portion of the structure must have been submerged to allow a ship to run-up and founder on top (Raban, 1999; Fig. 3B). Because Josephus praised the harbor in grand terms and referred to it as a functioning entity around A.D. 75-79, and yet portions of the breakwater were submerged by A.D. 83-96, we conclude that there was a rapid deterioration and submergence of the harbor, probably through seismic activity. - Reinhardt and Raban (1999)


• The submergence of the outer harbor break-waters at the end of the first century A.D. could have also been due to seismic liquefaction of the sediment. Excavations have shown that the harbor breakwaters were constructed on well-sorted sand that could have undergone liquefaction with seismic activity. In many instances the caissons are tilted (15°-20° from horizontal; Raban et al., 1999a) and at different elevations, which could be due to differential settling (area K; Fig. 1). However, the tilting could also be due to undercutting by current scour from large-scale storms (or tsunamis) and not exclusively seismic activity. Our data from the inner harbor cannot definitively ascribe the destruction of the harbor at the end of the first century A.D. to a seismic event, although some of the data support this conclusion. However, regardless of the exact mechanism, our sedimentological evidence from the inner harbor and the remains of the late first century A.D. shipwreck indicate that the submergence of the outer breakwater occurred early in the life of the harbor and was more rapid and extensive than previously thought. - Reinhardt and Raban (1999)


• 4.5.4. Tsunami Deposits in the Eastern (Inner) Basin
  
  Excavations in the eastern basin [40] yielded a thin layer of sediments from the 1st to 2nd centuries CE, overlain by a deposit of mixed sediments. They determined that in the 1st century, and evidently up to the 3rd century CE, the prevailing conditions in the eastern basin were of a brackish body of water with good circulation. Thus, the inner harbor seems to have been in use after 115 CE. The mixed sediment deposits discovered in the eastern basin was attributed by Reinhardt and Raban [40] to cleaning and deepening of the harbor in early periods. The proposed main mechanisms for the destruction of the harbor in the study by Reinhardt and Raban [40] were the seismic and tectonic scenarios. Later, however, after reassessing the finds in light of the available new studies on tsunamis, the tectonic and seismic scenarios, as well as the dredging deposit hypothesis, gave way to the 115 CE tsunami scenario [42].
  
  - Galili et al (2021:16-17,20)

• At the very deepest spot where the airlift penetrated, beneath huge stone blocks which teetered precariously above the divers' heads, was uncovered a large wooden beam. Beneath its protective cover the divers found the only whole amphora of our dig. This proved to be a second century Roman vessel. The fact that it was found under the tumbled beam and masonry would indicate that these things were catapulted into the sea at the same time. Since there is a strong earthquake recorded in the area of Caesarea in the year A.D. 130 [JW: this refers to the Eusebius Mystery Quake - could also be Incense Road Quake], it may possibly be that the harbor installations of Herod were destroyed at that time. - Fritsch and Ben-Dor (1961)

• Goodman-Tchernov et al (2009) identified tsunamites in cores taken immediately offshore of the harbor of Caesarea which Goodman-Tchenov and Austin (2015) dated to the 5th - 8th century CE and associated with tsunamis generated by the Beirut Quake of 551 CE and one of the Sabbatical Year Quakes. Although earlier works assigned this 5th - 8th century tsunamite deposit solely to the Beirut Quake of 551 CE, later revisions assigned this offshore deposit mostly to one of the Sabbatical Year Quakes with the suggestion that the Sabbatical Year Quake tsunami deposit contained some reworked tsunamites from the Beirut Quake of 551 CE. The revision may be based on the analysis of re-interpreted landward tsunami deposits (see Fig. 14 above from Galili et. al., 2021) which were dated by Dey et al (2014) to around the time of the Sabbatical Year Quakes. The chronology of the cores was determined using an assemblage of ceramic finds, radiocarbon, and optically stimulated luminescence (OSL) dating. Multiple indicators were used to distinguish tsunami deposits from storm deposits. Particle size distributions were shown to be particularly helpful and reliable. Tsunami horizons were characterized by a wider range of grain sizes and poorer sorting.
  
  Although efforts to distinguish two tsunami events in the 5th-8th century tsunamogenic deposit by coring in deeper water where an intervening layer, for example, might be present are reported in publications such as Dey et al (2014), this has not yet, to my knowledge, been accomplished. Tsunamogenic evidence for for an event in the mid 8th century CE (e.g. the Holy Desert Quake of the Sabbatical Year Quakes) is better supported than for the 551 CE Beirut Quake although it is possible that both earthquakes generated a tsunami which struck Caesarea.


• Tyuleneva et. al. (2017) identified what appears to be the same tsunamite in a core (Jisr al-Zarka 6) taken offshore of nearby Jisr al-Zakra. This core was located ~1.5-4.5 km. north of the Caesarea cores. The tsunamite deposit from Jisr al-Zarka was more tightly dated to 658-781 CE (1292-1169 Cal BP) – within the time window for the Holy Desert Quake of the Sabbatical Year Earthquake sequence.

• Goodman-Tchernov and Austin (2015) produced a description of a potential tsunami deposit in the shallow intermediate harbor.

  In excavations of the shallow intermediate harbor (TN area, Fig. 1C; Reinhardt and Raban, 2008:155-182 ), there is an extensive deposit of mixed (Early Islamic- Byzantine–4th to 8th century CE) refuse, ranging from high-value intricate items of varying erosion state and exposure—suggesting broad mixing of typical harbor refuse (e.g., broken amphora/pots) and newly introduced, undamaged domestic wares and personal items (e.g., intricate hair combs, fine sections of Islamic coins, statuette, a satchel of copper coins). Unlike other harbor deposits, these materials are of broad origin (domestic, commercial, religious), value range and preservation state, suggesting the kind of non-deliberate and rapid burial a tsunami event would produce. In addition, because the ages of the ceramics found in this excavation range from early Islamic to late Byzantine (6th through 8th centuries CE), no distinctive stratigraphy offshore today separates what may have been two distinct tsunami events.

  Dey and Goodman-Tchernov (2010:278) reported on potential 6th century CE tsunami deposits in the inner and outer harbors.

  The inner harbour was blanketed with a thick deposit of heterogeneous rubble, including bones and other organic remains, pottery, and architectural materials.⁶³ Meanwhile, in the outer harbour, a powerful scouring effect mixed materials datable from the 1st c. B.C. to the 6th c. A.D. into a single, undifferentiated mass, further undermined the breakwaters, and cut a trench into the channel between the outer moles.⁶⁴ The signs from both the inner and outer harbour are dramatic enough to have led previous commentators already to propose the tsunami of 551 as a possible cause.⁶⁵
  
  

  Footnotes

  [63] Raban 1996, 662; Yule and Barham 1999, 277-78; Reinhardt and Raban 2008, 177-78.
  
  [64] Reinhardt and Raban 2008, 178-79.
  
  [65] See, e.g., Raban 1996, 662; Yule and Barham 1999, 277-78; Reinhardt and Raban 2008, 177-78.
  
  

Site LL is located just north of Caesarea's inner harbour. Ad et al (2018) excavated the site which was in use from the Herodian period to the Umayyad period. A storage structure (aka "the warehouse") was identified in the western part of the site which appears to have been constructed in Herodian times and remained in use, as it underwent changes, until the middle of the Umayyad period (~700 CE). After the Islamic conquest of Caesarea (640 CE), rooms were partitioned, floors were raised, construction was added and some of the openings were sealed. Ceramics indicate that the site was abandoned at the end of the 7th century CE after which it suffered two major destruction events before re-occupation occurred in the mid 8th century CE in what was interpreted as Abbasid Strata V (the Abbasid Caliphate began ruling in 750 CE). During the renewed Abbasid occupation, destruction debris were preserved as the builders preferred to level the area and build above the destruction layer(s). The destruction events within Stratum VI (Umayyad) appear to be an earthquake and a tsunami; both likely a result of the the Holy Desert Quake of the Sabbatical Year Quake sequence.

Ad et al (2018) report that during the earthquake event several ceilings collapsed inward, and there was evidence of a fire in the eastern warehouse.¹ In the collapse in the corridor, the original order of the courses of the wall or vault could be clearly identified (Fig. 8) adding confidence to a seismic interpretation. During the subsequent tsunami event, a layer of sand and collapsed building stones had accumulated to a height of more than 2 m in Rooms 8–11 in the western warehouse and to a height of 1.5 m in Rooms 12–14 and the corridor of the eastern warehouse. Everhardt et. al. (2023) further examined the destruction deposits by taking cores and radiocarbon samples as well as examining burn evidence and a baulk inside the collapsed corridor.

The cores (C1 and C2) were taken in the collapsed corridor after the Abbasid floor was removed, thus sampling the destruction deposits. See Fig. 1E for location of the cores (and southern baulk) and Fig. 3 for photos and descriptions of the cores and the southern baulk. A ~20 mg. charcoal sample from the top 3 cm of sediment in the Umayyad archaeological fill and one untreated sample of various organic material (~20 mg) from the top 5 cm of the same layer in core C1, as close as possible to the contact with the lower anomalous deposit, were collected for radiocarbon dating. Everhardt et. al. (2023:14-15) report that radiocarbon dates of charcoal and organic material from the upper contact of the Umayyad archaeological deposit (Unit C) range from 605 to 779 CE² which is in agreement with the phasing of Ad et al (2018) and compatible with destruction layers that were deposited in 749 CE.

Cores C1 and C2 were sampled and analyzed for grain size distribution, foraminiferal assemblage, total organic carbon (TOC), and Inorganic Carbon (IC). An additional 13 surface surface samples, including from storm surge deposits, were also collected, analyzed, and compared with the analysis of the Cores and Southern Baulk in order to help distinguish if a tsunami deposit was indicated in the cores and baulk. Portable-Optically Stimulated Luminescence (P-OSL) dating was also performed on the cores. Four sedimentary units (A-D) were identified in the two cores are were described as follows :

• In addition, there appears to be evidence of landward tsunami deposits. After the Muslim conquest in the 7th century, Caesarea depopulated. In the late 7th or early 8th century CE, the coastal strip south of where the Crusaders would later build their fortifications was transformed into lush terraced gardens irrigated by wells and cisterns ( Dey et al, 2014). Marine layers found on top of these gardens included Glycymeris, a non-edible deeper water bivalve. Atop the marine layer was, in some areas, a burial ground with a funerary inscription providing a terminus ante quem of 870 CE. A terminus post quem of c. 500 came from a reflecting pool fronting the Temple platform and overlain by the marine layer. Dey et al (2014) suggest that the most likely explanation for the transformation from gardens to burial ground was an intervening episode of tsunamogenic destruction. They discussed the potential landward tsunamogenic deposit as follows:

  The most substantial strata attributable to a marine inundation of mid-8th-c. date appeared in the SW sector, along the coastal strip south of the Crusader fortifications. Extensive tracts of these deposits between the temple platform and the theater, a shore-parallel distance of nearly 800 m, were uncovered (and removed, usually mechanically) in the 1970s and early 1980s under the auspices of the Joint Expedition (JECM). The bulk of the deposits lay in a shallow depression situated c.10 m above mean sea-level (MSL) and separated from the sea by a low ridge 15 m above MSL. From the landward side of the ridge, beginning c.50 m from the shore, these marine layers stretched inland as far as 300 m from the sea. ¹⁴ They comprised two distinct, superimposed sequences, each consisting of a thick, lower layer of densely-bedded (and in some cases imbricated) shells, rubble and sherds up to 1.5 m thick, topped by a dark, silty layer 20-40 cm thick. Datable materials in the second, upper sequence placed its formation around the 14th c. ¹⁵ In the lower sequence, dated by the excavators approximately to the 8th c. on the basis of finds, numerous disarticulated human remains turned up, as well as at least one complete skeleton in Area C, interbedded with the surrounding strata of shells and silt. ¹⁶ Like the rest of the materials, this corpse was probably deposited by a (cataclysmic) natural event. As D. Neev and K. Emery indicated in their report, there were no signs of a man-made grave, and the surrounding horizontal strata were uninterrupted above and below the skeleton; such 'culturally non-appropriate burials' are now recognized as a typical feature of tsunami deposits.¹⁷ The most likely scenario would have corpses deposited by the retreating waters of the tsunami and immediately covered with more detritus, keeping the articulated skeleton undisturbed by scavenging animals or human intervention.



• Excavations carried out on the coast of Caesarea yielded deposits which were associated with 6th and 8th century CE tsunami events (Figure 14) - Galili et al (2021:16-17,20)

• At Caesarea, the best evidence of destruction attributable to the 749 earthquake comes from Area TPS, on the S side of the Temple Platform, where a thick layer of debris marks the end of the Umayyad occupation of the Late Byzantine bath complex, which was subsequently mulled and built over in the later 8th century - see Raban and Yankelevitz (2008:81) and Arnon (2008:85). Another probable effect of the earthquake was the collapse of the octagonal church on the platform - see Holum et al (2008:30-31). - Dey et al (2014)