Of the year AD 365, writers such as the sophist Libanius recalled the terrible event of a mighty earthquake that shook the island of Crete. The quake had come from beneath the seas, causing a huge and devastating tsunami to wash over the island. It was just one in a long line of earthquakes to unsettle this most divine of Greek islands.
Yet nobody had really considered what effect they may have had on the topography of the island – until 1851, when Captain (later Vice-Admiral) Thomas Abel Brimage Spratt of the Royal Navy visited Crete for surveying purposes, which involved an archaeological exploration of the island. Though never fully acknowledged, it was Spratt who discovered the way in which relative levels of land and sea had changed over the island in historic times. But how did he come to these conclusions? During my study of Spratt, I conducted a thorough search of his original letters, among others, to the geologist, Sir Charles Lyell, held at the University of Edinburgh. These provide fascinating insights into Spratt’s voyage of discovery.
The Eureka moment
The first letter pertinent to this story was written following a meeting with Lyell, when Spratt wrote to him to clarify a point about the island’s movement:
Dear Sir Charles,
Fearing you may be impressed with the idea that the eastern end of Crete had gone down as much as the west. I am induced to write a line to rectify it, if so; and to state that movements in the eastern half of the island have neither been as great nor apparently as uniform as the western movement. Both are subsequent to the historic period and the evidences are in both instances indicated by the elevation or partial submergences of some ancient Greek building or city.
The letter was written on 28 February 1856, which was a Thursday. The two must have met the previous evening because the following day, 29 February 1856, Spratt wrote again to Lyell confirming the situation, perhaps as an afterthought:
My dear Sir Charles,
You understood me quite right on Wednesday evening in respect to the fact that the western half of Crete having been elevated, and the eastern half depressed or gone down a few feet.
In the book Crete: Its Past, Present and People (Faber & Faber 1977), author Adam Hopkins wrote that ‘He [Spratt] noted quite correctly, that much of western Crete had risen by a whole eight metres. It was also believed, wrongly, that eastern Crete had sunk by a comparative extent.’ Hopkins does not make it clear as to whom he means by ‘it’ but the above letter (of the 28 February 1856) to Lyell showed that Spratt certainly did not believe this.
Tipping E, W, N and South!
This submergence of the east coast can be seen today at the Minoan (Bronze Age) palace site of Kato Zakros as part of it is underwater even in mid summer. However, Spratt realised that the movements were not simply restricted to the east and west tips of the island.
In the same letter to Lyell, dated 29 February 1856 (above), Spratt observed that there was a maximum elevation of nearly 26ft occurring on the south coast at the base of the White Mountains to the west of Sphakia, 17ft to the extreme west of the island and declining to 6ft or 7ft along the north coast to Suda Bay, just east of Khania. He added that ‘all the ancient cities included in this line of coast have been affected by the elevation by the conversion of their ancient ports into dry land.’ At first, for some reason, he found this puzzling, not thinking until a little later, that the elevation must have ‘occurred subsequent to the existence of these cites.’
Spratt had discovered this movement when searching for evidence of the ancient port of Kutri at Phalasarna on the western end of Crete. He noticed possible ancient activity some distance from the sea and, on 18 September 1853, he wrote to his friend, a seasoned traveller of the Greek mainland, Colonel William Leake (the letter was read out at the Royal Geographical Society on 13 March 1854 and thereafter published in its journal):
I made an interesting discovery in the western part of the island [Crete] – viz. that it has been subject to a series of elevations amounting at the maximum to 24ft 6ins … On going to Phalasarna I looked for its ancient port, mentioned by Scylax, and in the stadiasmus, as the emporium. But I could find no artificial work in the sea. There is, however, a long ledge of rocks, or rather an islet which lies off it, helping to form a natural but not an artificial harbour. This satisfied me in part, till, on examining the ruins, I saw in the plain a square place enclosed by walls and towers, more massive and solid than those of the city … I was instantly impressed, for several reasons, that here was the ancient port or artificial port, although full 200 yards from the sea and nearly 20 feet above it. My first idea was that the ancients had a means of hauling their vessels into it as a dry dock; but at last the coast elevation was uncumbered (sic) and on measuring the sea mark at its upper level here I found that the bed of this anc[ient] port is now 3 or 4 ft below that level …
On his first inspection of the site Spratt was unable to reconcile himself with Robert Pashley’s theory (17 years earlier) that the port was the mere indentation of the rocky coast-line under the walls of the city. Spratt could find no beach where a ship could be landed safely, as he wrote in his 1865 book Travels and Researches in Crete (vol. II):
Consequently, as the indentation was open and exposed to all south-easterly breezes, and the whole western swell for a distance of 500 metres or more, and the low outlying islet of Petaledes off it affords but little shelter to the bay, I could nowhere recognize the trading-port, and left the place with its phenomena greatly puzzling me.
Spratt then recalled a visit to the island of Cerigotto (Antikythera – northwest of Crete) where he had noticed an elevation of coastland (but did not expand on this) and it occurred to him that the same may have taken place on Crete, although to a much greater scale. He then measured the new sea-mark with the old sea-mark on the cliff around ‘the bluff headland upon which the city [Phalasarna] stood’. This convinced him that it had elevated as the new sea marks were 3ft below the old marks. This justified his theory that the inland ‘quadrangular space enclosed by the unusually massive Hellenic [4th century BC Hellenistic] walls upon the plain in front of the chapel of Aghios Giorgis’ was, indeed, the port. In fact, the port is of Minoan origin.
In his letter to Leake, he originally dated this western movement of the island to a date ‘prior to history’ (presumably pre 776 BC – first Greek writing) but was unsure, suspecting a more recent date due to a possible change in the markings on the landscape – concluding with a period ‘subsequent therefore to the decline of the Roman Empire’. In volume II of his book he dated it to the late Roman period. Indeed, the tectonic displacement has subsequently been dated to the 5th century AD.
…To northern cities
Having discovered this rise in the west, Spratt then moved to the northern part of the island, to Spinalonga, itself, on the inner west coast of the Mirabello gulf and connected to the mainland by the isthmus of Porus. Within this isthmus Spratt noted in his book (vol. I) the submerged ancient city of Olous – although at the time he thought it Olontion, believing Olous to be Goolas (Lato), some 12km further south near Kritsa. Underwater, but close to the shore, there is a small area of wall and some squared and shaped stones. Further out in deeper water there are cracked flagstones and the remains of a pavement and more walls, possibly shipberths (now a dangerous place to snorkel/dive due to frequent tour boats and erratic jet skiers).
This northern submerged city, suggested S G Spanakis, in his c.1960 book Crete, A Guide to Travel, History and Archaeology, was due to ‘a local subsidence soil’ (being no more specific) and not, he said, ‘by a general subsidence of the eastern part of Crete as Spratt believes (II.232).’ In fact, Spratt, on page 232 of volume II of his book, made no mention of the eastern subsidence affecting the northern part of the island. Spratt’s reference to the northern subsidence is in his first volume and he gave no reason for its occurrence.
Crete lies in between the Eurasiatic and African plates of the earth’s crust which are, and always have been, earthquake zones. It is hardly surprising, therefore, that the island has moved by varying degrees over the centuries. It was Thomas Spratt who made the discovery of the movements, yet he was reluctant to indulge in its credit by way of publication (he only mentioned it briefly in his book). It was his letter of the 18 September 1853 to Leake (referred above) that revealed the phenomenon and it was Leake who sent the letter to the Royal Geographical Society (RGS) for publication. Other than receiving Fellowships to various Societies, including the RGS, Spratt was given little academic recognition for any of his work on Crete. Accordingly, on 10 October 1857, Leake felt obliged to write to the President of the RGS, Sir Robert Murchison (letter found by the writer at the RGS):
Capt Spratt has for a long time been employed under the orders of Sir Francis Beaufort in surveying the coast of Greece and has first completed those in Crete; and I feel persuaded that you will agree with me in thinking that no person living has contributed in a more important degree to the great objects of our Society than Captain Spratt.
It has been extraordinary to uncover these letters, to thus see exactly how Spratt worked out how Crete tipped, and to prove his centrality to solving this Cretan conundrum. All salute Captain Spratt!
SOURCE: Dr Dudley Moore is a Visiting Research Fellow at the University of Sussex.