3 The plan is based on and seeks to supplement the plan in Perachora i, pl. 138. The depths given are those at low tide, at 12.15 p.m. local time (10.15 a.m. G.M.T.), on 28 May 1964, when the absolute level was 0·09 m. above chart datum. According to the weather charts for that day wind and weather conditions in the area will not have significantly influenced the water level. My datum level was the same as that Perachora i, pl. 138. However, that level seems to have been intended to represent mean sea-level, though this is not expressly stated, as it appears from the notebooks to be approximately the mean between the two measurements made from a levelling point on the terrazza floor in front of the temple. These measurements differed by 0·69 m., and must have been taken roughly, though apparently not deliberately, at high and low tide. Even so the difference is surprisingly high, for the tide range at Perachora varies between 0·58 m. (spring tides) and 0·15 m. (neap tides), but a greater range is possible in the small enclosed harbour. The date when the measurements were taken is not given.
I should like to thank Mr. N. M. Verdelis, then Ephor of Antiquities for the Argolid and Corinthia, for permission to work at the site; to Mr. Ian McLaughlin and Michaeli Thodis, the Phylax, for their help on the site; to Mr. J. J. Coulton for a discussion of points concerning the original survey of the harbour area; and to Dr. Habich and the German Hydrographie Institute for information on tides.
4 On Perachora, cf. Perachora i. 3, n. 3 (Dunbabin).
Argument has continued since the end of the last century; geologists are reluctant to commit themselves on such recent phenomena. Incidences of coastal submersion, and occasional emergence, are found in many parts of the Mediterranean area and also on the coasts of northern Europe. Until recently these were usually explained as the result of isolated sinking or rising of the coast-line due to geological instability. The accumulation of evidence has now shown far more examples of submersion than the reverse. Many scholars now argue that this indicates that another factor is involved, a general rise in sea level during the past three millennia; others maintain that many areas of land may have sunk without compensating rises elsewhere. The theory of a general rise in sea level was put forward, in a discussion of the Aegean area, by Negris, Ph. (AM 1904, 340–63) and has been maintained more recently by von Gerkan, A. (Festschrift Dörpfeld (1933) 37–42, ‘Meereshöhen und Hafenanlagen im Altertum’, now republished in his Gesammelte Aufsätze 139–42; Nachrichten Akad. Wiss. Göttingen (phil.-hist. Kl.) 283–99) and Hafemann, D. (Abh. des deutschen Geographentages xxxii (1959) 218–31, ‘Die Frage des Eustatischen Meeresspiegelanstiegs in historischer Zeit’, with a clear exposition of the problem; Die Umschau 1960, Heft 7, 193–6). Negris suggested a rise of c. 3·5 m. since the Classical period, clearly too high a figure; Hafemann accepts a figure over 2 m., again too high, I feel; v. Gerkan suggested 1·50+ m.; I myself think that we cannot yet give a more specific figure than 1–2 metres. A minimum figure is provided by the depth of submersion of buildings which were obviously built as land structures (not, for example, moles or quays) and a maximum figure can be established from the evidence of fish-tanks and slipways which must have been built with a certain depth of water in them. Isolated evidence is insufficient since geological instability is a factor which must always be taken into account in the Aegean area (especially in the Corinth region). A mass of evidence must be accumulated before a rise in sea level can be proved as a common factor, and the amount defined more closely.
For other evidence of coastal submersion cf. Hammond, N. G. L., JHS lxxvi (1956) 35; Cook, J. M., BSA liii–liv (1958–9) 11 f.; J. Leatham and Sinclair Hood, ibid. 263 ff.; Schäfer, J. and Schläger, H., AA 1962, 40–51; J. du Plat Taylor, Marine Archaeology, chapters 5–6. At Cenchreae, not far from Perachora, a change of 6–10 feet since Antiquity is indicated (Scranton, R. L. and Ramage, E. S., Hesperia xxxiii (1964) 143). Cf., most recently, Hafemann, , Abh. math. -naturw. KI., Akad. Wiss. Mainz, 1965, 605–88, Nr. 12.