The Holocene Sea-level of the Coast of Israel Dorit Sivan The Department of Maritime Civilizations and the Recanati Institute for Maritime Studies (RIMS), University of Haifa, Israel. [email protected]
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Akko HAIFA 3 Atlit Dor -5 Mediterranean Sea 2 Caesarea
TEL-AVIV - YAFO -10
Ashdod JERUSALEM Ashqelon -15 relative sea-level (m) relative 1
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The Holocene sea-level curve of the Mediterranean coast of Israel is Location map by Prof. J.K. Hall, Geological a result of 3 research stages. For most of the Holocene up to 2,000 Survey of Israel years ago, and from the 1st century AD up to the 13th century AD, the curve is based mainly on land and underwater archaeological data ( ). The observational limits are compared with the glacio-hydro- Land and underwater archaeological data such as: isostatic models across the region. For the last 1,000 years we use bio- constructions ( ).
Bio-construction as sea-level indicator:
Maagan Michael shipwreck dated to about 2400 BP. Man-made rock-cut pool, Shiqmona, south of Haifa. Abrasion platforms along the rocky coast of Israel. Cores were drilled in the Vermetid reef, using a pneumatic corer.
The Pre-Pottery Neolithic submerged site of Atlit Yam: A core composed mainly of The top of the well is at present Dendropoma reef unconformably at a water depth of -10m, and overlying the sandstone substrate. its bottom is at -15.5m. A domestic well excavated The base of the Dendropoma reef Photograph by Dr. E. Galili. in the inner harbour of is assumed to be an indicator of Caesarea. sea-level. SEM magnification of Dendropoma Caesarea: the archaeological site and the petraeum. remains of the sunken harbour. Ancient Photograph by Dr. D. Sivan at the University of Aix-Marseille, Caesarea was built by King Herod of Judea France between 22 and 10 BC. The results of the three research stages:
1. From 9,500 y BP to 2,000 y BP (Early 2. From 2,000 y BP to about 700 y BP (end of 3. The last Millennium Roman period) the Crusader period)
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-15 Depth (cm) 20 -20 relative sea level (m) relative relative sea level (m) relative 25 -25 rsl-upper limit rsl-lower limit 30 -30 10 8 6 4 2 0 0 500 1000 1500 2000 time Cal. y. BP time Cal. y. BP Cal. y. BP
The comparison indicates that at about 9,500 to 9,000 years BP sea- The Caesarea results indicate that about 2,000 years BP sea-level The Dendropoma petraeum reef along the abrasion platform, is the level was not higher than -16.5m, and probably about -20m, or lower. was at its present elevation, while during the Byzantine period it tool for reconstructing palaeo-sea-levels for the last 1,000 years. By 8,000 years BP, sea-level had risen, but was still not higher than was at or above its present level (about 30cm 15cm). During the Unfortunately, both the elevation accuracy ( 10 to 20cm) and the about -7m, and was probably about -10m, or lower. According to Crusader period sea-level may have been lower than today by about range of the corrected and calibrated radiocarbon dates obtained the model predictions, sea-level was still lower than -3 to -4.5m 6,000 40cm 15cm. from Dendropoma do not provide high-resolution data for the rising years BP, and remained below its present level until about 3,000 to sea. It seems that sea-level rose slowly from the relatively low levels 2,000 years BP. of the Crusader period to the present level by the 19th century. Conclusions:
a. Sea-level reached its present elevation b. The tectonic factor along the c. Sea-level has been lower by about ± 30cm than (± 10-15cm) at about 2,000 y BP, while coast of Israel has been negligible the present level since about 700 y ago, stayed during the Byzantine period it was at for the last 9,500 years. lower for few hundred years, and rose by about or above the present level (about 20-25cm during the 20th centuary ±30cm). During the Crusader period sea-level may have been lower than c. 30 Monthly mean sea level variation (cm) Ashdod - Tel-Aviv between 1990-2002 20 today by about ±40cm. 6 9 5 7 10 8 10,11 12 4 18 19 20 0 13 14 17 21 -10 2 3 15 1 16 22 -20 23 24 25 -30
-40 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 b. c. Ashdod Tel-Aviv The north-south aqueduct bringing Mediterranean tide-gauge data obtained High resolution data obtained by measurements water to Caesarea, dated to the first few from 134 stations indicate that average along the coast of Israel show a sea-level rise of centuries AD, strengthens our conclusion sea-level rise for the last 100 years ranges 10cm at Ashdod and Tel Aviv stations between a. of absence of vertical tectonic movements between 1.0 and 1.5mm/y (10-15cm). 1990 and 2000. This is in addition to a 5cm rise over the last 2,000 years. between 1977 and 1991, which means a 25cm rise A proposed reconstruction of Caesarea during the first over 25 years. few centuries AD.