Extreme events in the Holocene geological record of Corfu (Ionian Islands, Greece) and their influence on man and environment - XTREME EVENTS
Final Report Abstract
The XTREME EVENT project focused on the identification of different kinds of extreme events in Holocene sedimentary archives on Corfu (Ionian Islands, Greece) using a geomorphological and geoarchaeological approach. Extreme events in the Mediterranean in general and on Corfu Island in particular can be related to climate change, human impact, co-seismic crust movements or extreme wave events such as storms and tsunamis. Against this background, we based the research design on a variety of modern systemic and complex methodological approaches in order to obtain multi-proxy data sets for the evaluation of ecosystem conditions and event-related relevant changes. Our studies focussed on the harbours of the ancient city of Corcyra (nowadays Corfu City) and were accomplished by selected study sites in different environmental settings across the entire island. We show that Corfu Island and its ancient harbours were affected by seven tsunami-related extreme wave events that occurred between the 6th millennium BC and modern times. Based on the geographic position and hydrological conditions of the northern Ionian Sea and the sheltered Gulf of Corfu, storms can be excluded as potential source for these extreme wave events. Six of the events are interpreted as tele-tsunamis originating from well-known source areas in the seismic highly active eastern Mediterranean, leaving their traces along the shores of many littoral states, one event is related to a local to regional co-seismic event that occurred between the 4th and 3rd cent. BC on Corfu Island itself. Beside tsunami-related signatures in the ancient harbours of Corcyra and in lagoonal environments in the southern part of Corfu, we also documented distinct earthquake-related destruction of ancient buildings in the course of archaeological excavations. In detail, we documented the following tsunami events in the sedimentary records of Corfu Island: Event I occurred between 5600 and 5200 BC, event II at or after 3900 BC, event III related to co-seismic movements of Corfu itself between the 4th and 3rd cent. BC, event IV at 365 AD, related to the devastating earthquake on Crete and associated tsunami, event V between the 5th and 6th cent. AD, related to the AD 521/522 and AD 551 events, event VI in the early 14th cent. AD related to the wellknown AD 1303 event and event VII, so far not precisely dated in early modern times. Keeping these results in mind, the project contributes to the reconstruction of the history of tsunamis in the eastern Mediterranean, showing the need of future research towards a solid hazard and risk assessment. Beside extreme wave and co-seismic events affecting the coasts of Corfu Island, we were able to detect a valuable archive of climate and human-induced environmental change. Located inland in the western part of Corfu and more than 35 m above recent sea level, the geoarchive of the Giannades Polje recorded palaeoenvironmental changes throughout the last nine millennia in high resolution comprising different kinds of events such as seismo-tectonic events, man-made as well as climatic signals. The analyses of the Giannades Polje record is still on-going and will be compared with seismotectonic as well as palaeoclimatic data from nearby sites for the time since the Neolithic period based on different palaeoenvironmental and palaeoclimate proxies such as tree ring, speleothem data and coastal sedimentary sequences. Future research will thus allow disentangling the complex interplay of climate change and human-environmental interactions in a highly relevant transitional region which is known to have been subject to various oscillations between Mediterranean and central European climates.
Publications
- 2016. Combined Electrical Resistivity Tomography (ERT), Direct‐Push Electrical Conductivity (DP‐ EC) Logging and Coring – A New Methodological Approach in Geoarchaeological Research. Archaeological Prospection 23(3), 213-228
Fischer, P., Wunderlich, T., Rabbel, W., Vött, A., Willershäuser, T., Baika, K., Rigakou, D., Metallinou, G.
(See online at https://doi.org/10.1002/arp.1542) - 2016. Impact of Holocene tsunamis detected in lagoonal environments on Corfu (Ionian Islands, Greece) – geomorphological, sedimentary and microfaunal evidence. Quaternary International 401: 4-16
Fischer, P., Finkler, C., Röbke, B.R., Baika, K., Hadler, H., Willershäuser, T., Rigakou, D., Metallinou, G., Vött, A.
(See online at https://doi.org/10.1016/j.quaint.2015.07.019) - 2018. Geoarchaeological investigations of a prominent quay wall in ancient Corcyra – implications for harbour development, palaeoenvironmental changes and tectonic geomorphology of Corfu Island (Ionian Islands, Greece). Quaternary International 473, 91-111
Finkler, C., Baika, K., Rigakou, D., Metallinou, G., Fischer, P., Hadler, H., Emde, K., Vött, A.
(See online at https://doi.org/10.1016/j.quaint.2017.05.013) - 2018. The geological record of ancient harbours – using ancient harbour geoarchives of Corcyra (Greece) to reconstruct the palaeoenvironmental development and to identify extreme events by means of a multi-proxy based geoarchaeological approach. PhD thesis, Institute of Geography, Johannes Gutenberg-Universität Mainz
Finkler, C.
(See online at https://doi.org/10.25358/openscience-2647) - 2018. Tracing the Alkinoos Harbor of ancient Kerkyra, Greece and reconstructing its palaeotsunami history. Geoarchaeology 33, 24-42
Finkler, C., Fischer, P., Baika, K., Rigakou, D., Metallinou, G., Hadler, H., A. Vött
(See online at https://doi.org/10.1002/gea.21609) - 2019. The sedimentary record of the Alkinoos Harbour of ancient Corcyra (Corfu Island, Greece) – geoarchaeological evidence for rapid coastal changes induced by co-seismic uplift, tsunami inundation and human interventions. Zeitschrift für Geomorphologie 62(2), 197-246
Finkler, C., Baika, K., Rigakou, D., Metallinou, G., Fischer, P., Hadler, H., Emde, K., Vött, A.
(See online at https://doi.org/10.1127/zfg_suppl/2018/0514)
