Vulcan's legendary landscape

Geological and human changes take place on different timescales. We are lucky if, like the Queen Mother, we reach a century, while land forms change over millennia. Except, that is, in areas of intense tectonic activity such as plate boundaries, where land forms can appear and disappear before one's eyes.

Such regions exercise a fascination for us, and have done throughout recorded history, as the elder Pliny found to his cost at Pompeii in AD 79.In 1866, natural scientists flocked to the Greek island of Santorini (or Thera) to observe a new volcano on the tiny island of Nea Kameni within its caldera. When the dust settled four years later, Nea Kameni had more than doubled in size, and modern, detailed study of Santorini's volcanic geology had begun. Scientific interest in 1866 also prompted the identification of walls found buried in a quarry on Therasia as remains of a prehistoric culture.

These were the first in a string of archaeological discoveries culminating in the now-famous excavations begun in 1967 by Spyridon Marinatos at the site of Akrotiri, which still continue. The comparison with Pompeii and Herculaneum - destroyed and preserved for archaeologists by another Mediterranean volcano, Vesuvius - was obvious, and it was Ferdinand Fouque who, in 1869, dubbed Santorini a "prehistoric Pompeii". Fouqué also summarised the state of knowledge of Santorini's geology and archaeology in Santorin et Ses Eruptions , published in 1879 and now available in a new edition.

Fiction, too, has never been far away from Santorini: Jules Verne's 20,000 Leagues under the Sea , first published in 1869, included a visit by Captain Nemo and the Nautilus to the caldera during the 1866-1870 eruptions, while Louis Figuier in 1872 proposed a link between the island's buried culture and Plato's tale of Atlantis in his Timaeus and Critias .

Public interest in Santorini continues, and, in this superbly illustrated book, first published in German in 1994, Walter Friedrich offers a contemporary account of Santorini's "natural history" similar in scope to Fouqué's of 1879. The phrase "the legend of Atlantis", new in the English edition's subtitle, is designed perhaps to enhance the book's popular appeal, as is its fiery dust-jacket depicting lava and sea water (actually from a Hawaiian volcano) and its competitive price for a hardback edition with nearly 200 colour illustrations. Although its cover and subtitle might suggest otherwise, Fire in the Sea is a sober and accessible treatment, incorporating the most recent geological research, in which Friedrich himself has played an important role.

The book's 14 chapters are arranged into four parts. The first, "The Geological Framework", takes us from the origins of vulcanism on the island (about 1 million years ago) to the time of the Bronze-Age eruption. Most impressive here (as throughout the book) are the clear colour maps and diagrams linked effectively to colour views of the island that show how the island changed its form prior to the 2nd millennium BC. Friedrich covers the 2nd-millennium eruption in the book's second part, "The Minoan Eruption and its Effects". He offers a concise account of the eruption's three phases, its effects in the wider east Mediterranean and how it is dated. The third and longest part, "The Volcano Releases its Secret", reconstructs Santorini's form at the time of the Minoan eruption, documents the extent of settlement, the floral, faunal and mineral resources available, and evaluates the geological case for linking the Minoan eruption with Plato's Atlantis tale. In the final section, "The Island Is Changing its Appearance", Friedrich records changes in Santorini's shape since the Bronze Age, making excellent use of historical eyewitness accounts, and hints at the volcanic activity that will come again. Three appendices contain excerpts from the relevant sections of Critias and Timaeus and lists of fossils and flora.

Explicitly aimed at the non-specialist, the book's excellent graphics facilitate a clear understanding of the island's natural history, helped by "boxes" in the text on basic topics such as plate tectonics, radiocarbon and ice-core dating. Nearly half the text is devoted to the island at the time of the Minoan eruption. There is no detailed discussion of the Akrotiri site and its finds: Friedrich's emphasis is on natural, not cultural history. That geological reconstruction is subject to constant revision is vividly demonstrated by a diagram showing differing reconstructions of the Minoan island from 1980 to the present, suggesting that Santorini has changed more in the past 20 years than it has in the past 3,500. We now know that Bronze-Age Santorini, like its modern counterpart, surrounded a caldera with a small island at its centre. In archaeological studies, the absolute chronology of the Minoan eruption has generated a vast specialised literature because it is crucial to understanding the pace of cultural change and the precise nature of cultural interactions in the Aegean in the mid-2nd millennium.

Friedrich devotes a short chapter to the topic, in which he reviews all the evidence (archaeological, radiocarbon, dendrochronological, and ice-core) and adopts a date of 1640 BC for the eruption. This date will please some, but there have been developments since 1994, usefully summarised in Stuart Manning's A Test of Time (1999), and questions still remain. The inclusion of the Atlantis story may seem controversial. However, there is a long tradition linking Atlantis to Thera, and Friedrich's discussion is balanced, merely pointing out ways in which Santorini's geology might fit with Plato's story. Given the wealth of eyewitness accounts from historical periods, it would be quite surprising if echoes of such a major catastrophe were entirely absent from later Greek traditions.

This book, with its clear text and superb illustrations, is a suitable geological complement to the lavishly illustrated publications of Santorini's archaeological remains. Those wishing to place those remains in a physical context will find it most rewarding.

John Bennet is lecturer in Aegean prehistory, University of Oxford.