The study of sea-level changes and shoreline dislocations during the
Holocene is becoming important as population density in the coastal
zone has increased and human activities were, are and will be affected
by changing coastal conditions. Obviously, a prediction of future
shoreline and sea-level developments needs an understanding of the
processes that influence local and regional shoreline dislocations in
the past, respectively during the Holocene.
In this context, this volume of the Zeitschrift für Geomorphologie
presents several important results of an international workshop on
Holocene sea-level changes in the Eastern Mediterranean region
focusing on potential causes for local, regional and global sea-level
changes, the accuracy of sea-level indicators and human impacts on
local shoreline displacements, especially during the Neolithic and
Classical periods. In 16 contributions scientists from Greece,
Germany, England, France, Israel and Sweden present their recent
results and discuss a diversity of potential causes for local and
regional sea-level changes and shoreline dislocations.
D. Kelletat discusses the accuracy of sea-level indicators common on
the Mediterranean coastlines and presents a generalized sea-level
curve of the Younger Holocene for the Eastern Mediterranean. He states
that more absolute data is needed for a reliable reconstruction of
sea-level changes especially between approx. 6,000 to 2,500 BP, and
that aside from this, a general agreement on the accuracy of sea-level
indicators is urgently needed to check local curves on their relevance
for sea-level reconstruction.
H. Brückner focuses on the Holocene shoreline displacements around the
ancient harbour city of Ephesus (Western Turkey). The reconstruction
of the delta progradation of the Küçük Menderes river and its
tributaries in space and time resulted primarily from the
sedimentological facies and faunal composition of numerous sediment
cores. The detailed chronostratigraphic framework is based on
radiocarbon data, ceramic findings and published archaeological and
historical records.
Relative sea-level changes in Marseille’s ancient harbour (France)
during the last 5,000 years are investigated by Ch.Morhange. The study
uses biological sea-level indicators (barnacles, calcareous algae
layers) and archaeological data for reconstructing sea level. In
contrast to sea-level curves from the Eastern Mediterranean, the
author postulates a regular rise in relative sea level up to about 500
years AD without any sea-level oscillations.
Based on two recent case studies from central Greece (Gulf of
Atalanti) and the southeast Aegean Sea (Astypalaea), A.Cundy describes
the possibilities of using coastal sedimentary records for
reconstructing rapid sea-level changes (Tsunami impacts, co-seismic
shoreline displacements).
E.Fouche et al. suggest a continuous sea-level rise during the Late
Holocene at Mykonos, Delos and Rhenia islands (Cyclades, Greece). They
used beachrock for dating with radiocarbon and as sea-level indicator.
They state that beachrocks were formed in the intertidal zone, whereas
D. Kelletat (see article in this volume) postulates a development in
the supratidal environment.
M. Bar-Matthews and A.Ayalon use stable isotope compositions of
speleothems from the Soreq Cave in the Judean Mountains (Israel) for
Holocene paleoclimatic reconstructions. They describe several sharp
climatic events associated with decrease in rainfall and the impact on
human settlements in the Eastern Mediterranean.
D. J. Blackman discusses evidences that archaeological sites from
diverse locations in the Eastern Mediterranean can provide to
reconstruct sea-level changes in the past and the human reaction to
these changes. The author emphasizes the productive co-operation
between archaeologists and geomorphologists in understanding coastal
changes.
P.A. Pirazzoli focuses on indicators of tectonic movements, especially
in the eastern Mediterranean area. The author shows that features of
marine erosion (tidal notches and benches) and bio-construction
(reef-forming coral, vermetids and calcareous algae rims) are the most
useful indicators to reconstruct tectonic movements and former
sea-level changes.
The effects of four ancient major earthquakes associated with coastal
uplift or subsidence on four prehistoric and Late-Roman coastal sites
in Greece (Aghia Irini, Vouliagmeni Lake, Aigeira; Kisamos) are
presented by S. S. Stiros. The author points out that strong
earthquakes may have had disastrous effects on ancient towns and
societies. This could have lead to the abandonment of settlements or
to social and economic instability of societies.
N.-A. Mörner presents a detailed discussion of eustatic, tectonic and
climatic components of sea-level changes with special aspects on the
eastern Mediterranean. The author emphasizes that sea level within the
Mediterranean region is predominantly affected by complex local or
regional tectonic factors and regional eustatic changes, and he also
assumes that eustatic sea level in the Eastern Mediterranean is
affected by changes in precipitation and evaporation in the present as
well as in the past.
Using long-term tide-gauges M. N. Tsimplis discusses the correlation
between global sea level and sea-level variability in the
Mediterranean Sea during the past century. The author concludes that a
global sea-level trend is highly speculative and the understanding of
local, regional or global sea-level variations is still unsolved.
N. Fytrolakis, A.Peterek and B. Schröder present preliminary results
of geoarchaeological research on Holocene coastal changes in the
western Messara plain (Crete). Based on data from drilling and field
studies they show that both Agia Triada and Phaistos have been
situated at the eastern end of a marine embayment in early Minoan
time. The authors assume that, already during Minoan time,
anthropogenic soil and bedrock erosion induced rapid progradation of
river deposits. It furthermore initiated a reallocation of the Minoan
harbour next to Phaistos to the Kommos area and a strong coastal
retreat towards its modern position.
The Holocene formation and evolution of the northern deltaic margin of
Amvrakikos Gulf (western Greece) is described in detail by S.
E.Poulus, V. Kapsimalis, Ch. Tziavos, P.Pavlakis, G. Leivaditis and M.
Collins. The investigation is based on lithostratigraphic analysis and
radiocarbon dating of a number of sediment cores. The authors conclude
that the formation of the delta is the result of sea-level rise,
regional tectonism, riverine sediment supply and differential
compaction rates of the sedimentary infill.
Using similar methods K. G.Vouvalidis, G. E. Syrides and K. S.
Albanikis show the impact of sea-level rise on the morphology of the
Thessaloniki Bay. Their assumption of a nonoscillating Holocene
sea-level rise is based on only five radiocarbon dates.
E. Psomiadis, I.Parcharidis, S.Poulus, G. Stamatis, G. Migiros and
A.Pavlopoulos present a reconstruction of modern coastal changes of R.
Sperchios deltaic plain using remote sensing data covering the period
1945-1999. They show that significant coastline accretion occurred
during the time span of 1945--1984. Due to a strong reduction of river
water and sediment supply, the coastline has undergone a relatively
stable period between 1984-1999.
The volume ends with a field trip guide to the broader area of
Korinthos - Loutraki (Perachora) presented by H.Maroukian,
E.Karymbalis and K.Pavlopolous. Main topics of the field guide are the
seismicity and coastal evolution of the eastern gulf of Corinth with
focus on the area of Kenchreai (former harbour of Corinth), the
ancient port of Lechaeon, remains of the Diolkos at the western
entrance of the modern canal of Corinth, the Perachora Peninsula with
the small harbour of Heraeon and Lake Vouliagmeni.
All in all this volume offers an excellent approach to the wide field
of Holocene coastal evolution and sea-level changes in the Eastern
Mediterranean and to many local and regional aspects regarding the
reconstruction of eustatic sea-level changes, the influences of
tectonic, sedimentary and anthropogenic impacts on shoreline
dislocations, the significance of sea level indicators like beachrock,
notches and calcareous rims, and the dependences between coastal
changes and human settlements. The authors present a great variety of
methods including geomorphology and geochronology, geology and
sedimentology, geoarchaeology and archaeology, remote sensing and
tide-gauge records.
This volume is worth to be read not only by geomorphologists but also
by (geo-) archaeologists and others, who are interested in
palaeo-environmental changes in the Eastern Mediterranean.
Gerhard Schellmann, Bamberg
Zeitschrift für Geomorphologie 51/3, S. 399-401