3.000 Years of East Mediterranean Sea Levels: Archaeological Indicators from Greece Combined with Israeli Coast Data

Citation:

Dean S, Sivan D, Evelpidou N, Baika K. 3.000 Years of East Mediterranean Sea Levels: Archaeological Indicators from Greece Combined with Israeli Coast Data. In: 14th International Conference of the Geological Society of Greece. Thessaloniki, Greece; 2016.

Date Presented:

25-27 May

Abstract:

The study "3,000 Years of East Mediterranean Sea Levels" investigates whether trends observed during this period in Israel from archaeological indications can be corroborated and strengthened by comparing them with relative sea levels observed in Greece. The process is comprised of three questions: 1) What types of archaeological sea-level indicators in Greece and Israel have the highest level of reliability for dating and sea-level evaluation? 2) What are the overall trends of sea-level change in Greece and Israel during the last 3,000 years, and what degree of error do
these curves have? 3) What if any regional trends can be identified from the combined Greek and Israeli data? To answer the above questions, three objectives are pursued: 1) Identify archaeological RSL indicators of the last 3,000 years in Israel and Greece, including already published indicators with adequate measurements, those published but in need of new measurements, and unpublished potential indicators. 2) Assess the reliability of indicators using
a consistent scoring system, correction for isostatic and tectonic effects, more precise measurements from indicators, and by exploring new methods to determine the chronology of rock carved indicators in Israel. 3) Using the assembled data, create a sea-level reconstruction for Greece, and combine the data with existing reconstructions from Israel for an analysis of matching trends. The study began with research of published sources and was supplemented by field activity. Surveys in Greece including Crete to assess both published and potential indicators occurred. Ruins from Chersonisos and Matala in Crete were examined and new measurements were taken from the latter. Fieldwork was also performed in Israel, including measurements from Caesarea for functional elevations on water channels at the promontory palace pool, at Achziv's fishpond, and around Tel Dor. The survey collected nearly 140 indicators from Israel and about 120 from Greece (excluding those outside the project's chronological scope). Of the Israeli indicators, some 120 were deemed reliable enough for reconstructions, whereas in Greece only 40 were, and not all of these from tectonically stable areas. The higher reliability of the Israeli dataset may stem from a smaller coastline and more focused sea-level research over the past few decades. In Greece, many measurements were taken by archaeologists in the 20th century before precise surveying methods were available, and published without sufficient metadata. Since then some of the sites have also become inaccessible to sea-level researchers. Analysis of indicators revealed gaps and disparities between the two regional datasets. Israel has a very strong set of many indicators from the Roman Period (~2000BP) to present, but fewer from 3000-2000BP.
Greek indicators are strongly clustered in the Classical and Hellenistic Periods (2500-2000BP) with fewer before or after. These disparities make it difficult to effectively compare sea level between regions, but results suggest some correspondence of the curves. Analysis supports the work of previous Israeli researchers and suggests a relatively stable sea level there for the last 2000 years, with possible fluctuations not exceeding half a meter above or below current sea level at ~1500BP and ~750BP respectively. Both regions indicate a sea level rise between 2500-2000BP, but more data from Israel is needed to confirm this, while data from 3000-2500BP in Israel and Greece alike is scarce. In addition to the overall regional RSL comparisons, the current study also identifies the need for ongoing research and data collection: Continuing the search for sea-level indicators in Israel from 3000-2000BP, and in Greece from 3000-2500BP and from 2000BP to present, particularly in areas of reported tectonic stability like the Cyclades.