Geoarchaeological tsunami deposits at Palaikastro (Crete) and the Late Minoan IA eruption of Santorini

Abstract

The explosive eruption at Santorini in the Aegean Sea during the second millennium BCE was the largest Holocene volcanic upheaval in the Eastern Mediterranean region. The eruption was disastrous for the Minoan settlements at Santorini, but the effect on human society in the neighbouring islands and regions is still clouded in uncertainty. Tsunami generation was suggested, but comparatively little evidence was found. The lack of firm tsunami traces is particularly puzzling in Crete with its coastal settlements of the Late Minoan IA period, during which the Santorini eruption occurred. Here, we report the discovery of extensive geoarchaeological tsunami deposits at Palaikastro in north-eastern Crete. These deposits are characterized by a mixture of geological materials, including volcanic Santorini ash, and archaeological settlement debris. Various tsunami signatures were identified: (1) erosional contact with the underlying strata, (2) volcanic ash intraclasts in the lower part of the deposit, (3) reworked building stone material in the lower part of the deposit, (4) individual marine shells, (5) marine micro-fauna, (6) imbrication of rounded beach pebbles, settlement debris, ceramic sherds and even bones, (7) multi-modal chaotic composition. Late Minoan human settlement activities at Palaikastro provided architectural and stratigraphic frameworks in space and time that recorded and preserved tsunami evidence as geoarchaeological deposits. Such stratigraphic resolution and preservation may not occur in the natural landscape. Volcanic ash transported by wind from Santorini south-east to Crete preceded the tsunami. Geological, archaeological and radiocarbon dating criteria all converge, indicating that the tsunami deposits are coeval with the Minoan Santorini eruption. Field evidence suggests that tsunami waves at Palaikastro were at least 9 m high. Inverse tsunami modeling was attempted, based on these newly discovered tsunamigenic deposits. The initial wave in the generation region at Santorini that best fits the stratigraphic data is a wave with þ35 to À15 m initial amplitude and a crest length of about 15 km.

The Minoan Santorini Eruption and Tsunami Deposits in Palaikastro (Crete): Dating by Geology, Archaeology, 14C, and Egyptian Chronology

“…We focus in this article on the Minoan site of Palaikastro in northeastern Crete, where volcanic Santorini ash occurs within the archaeological stratigraphy 398 H J Bruins et al (MacGillivray et al 1991, 1998. Extensive tsunami deposits were discovered here (Bruins et al 2008), dated to the Santorini eruption based on geological, archaeological, and 14 C evidence. Table 1 Simplified conventional scheme of archaeological material-cultural relationships between Thera, Crete and Egypt in the 2nd millennium BCE, forming the basis of archaeo-historical dating linked to the Egyptian historical chronology.…”

“…These deposits are geologically dated to the Minoan Santorini eruption, because the embedded volcanic ash is proven to have the geochemical fingerprint of this eruption (Bruins et al 2008). Measurements of major elements on single volcanic glass shards from different locations at Palaikastro were conducted by Jörg Keller (University of Freiburg) using electron probe micro-analysis (EPMA).…”

“…Measurements of major elements on single volcanic glass shards from different locations at Palaikastro were conducted by Jörg Keller (University of Freiburg) using electron probe micro-analysis (EPMA). Measurements of trace elements were attained by Andreas Klügel (University of Bremen) using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) (Bruins et al 2008). …”

“…The Egyptian dates for the dynasties show options for both a "high" and "low" chronology, as discussed by Kitchen (1987) and Ward (1992); see also Kitchen (1996), Krauss and Hornung (2006 Figure 1 Location of the Santorini (Thera) Volcano and the archaeological sites of Palaikastro and Mochlos in NE Crete, where volcanic ash was found from the Minoan Santorini eruption. Tsunami deposits related to the latter eruption were discovered on Thera (McCoy and Heiken 2000b), along the Turkish coast in Didim and Fethiye (Minoura et al 2000), and on Crete in Palaikastro (Bruins et al 2008). …”

“…The term geoarchaeological tsunami deposit was introduced (Bruins et al 2008), as both archaeological and geological components appear together (Figure 3-5). The criteria and evidence for the identification of tsunami signatures in these deposits at Palaikastro were treated in detail by Bruins et al (2008). Figure 2 The area of Minoan Palaikastro, showing the present coastline with investigated field sections and the excavated part of the ancient town (left).…”