Ancient Greek Knew Geology Thousands of Years Before His Time

By Valerie Ross | June 7, 2011 10:00 am

The city of Piraeus, in 2008

What’s the News: Chalk up another win for the ancient Greeks. The Greek historian and geographer Strabo wrote nearly 2,000 years ago that Piraeus, a small peninsula near Athens, had once been an island—and a new study in this month’s issue of Geology shows he was right.

How Do We Know:

  • To test out whether Strabo’s claim was true, researchers took sediment samples from the area. Using radiocarbon dating to determine how old different layers of the soil were and analyzing the remains of ancient microorganisms trapped in the soil, the researchers reconstructed the ancient environment of the strip connecting Piraeus to the mainland.
  • While Piraeus was a peninsula 8,000 years ago, the researchers found, rising sea levels had flooded the land linking it to Athens. Sure enough, by about 6,000 years ago, Piraeus was an island.
  • Sediment deposits turned the water between Piraeus and the mainland into a wide lagoon by 4,000 years ago, the study showed. Further deposits over the next 1,500 years turned the area into a freshwater marsh, solid enough for the Athenians to build long walls connecting their city to its harbor at Piraeus during the 5th century B.C.

How Did He Know:

  • It’s pretty surprising that Strabo would know this about the peninsula’s past. Unlike the social or political changes often noted by historians, geological changes tend to happen on timescales too long for humans to observe, much less remember. At a time when historical records were less than reliable—the ancient Greek historian Herodotus is called both “the father of history,” for his careful research methods, and “the father of lies,” for the many, many inaccuracies in his works—how did Strabo get this right?
  • One possibility, the researchers say, is that the Piraeus’s history stuck around in the Athenian collective consciousness for millennia, thanks to oral tradition. The peninsula’s name, too, hints at its past: “Piraeus” comes from a word meaning “beyond” or “on the other side.” Strabo may have listened to people’s stories, done a bit of etymology, and started writing.
  • Another hypothesis is that Strabo, looking out over the unusually flat landscape with his trained geographer’s eye, picked out clues to the past. Strabo knew about the long walls built five hundred years before, and could likely have seen the traces of the freshwater marsh that once filled much of the peninsula. While he couldn’t have known exactly when Piraeus was an island, he might have deduced that water once separated it from the mainland.

[via Ars Technica]

Reference: Jean-Philippe Goiran, Kosmas P. Pavlopoulos, Eric Fouache, Maria Triantaphyllou & Roland Etienne. “Piraeus, the ancient island of Athens: Evidence from Holocene sediments and historical archives.” Geology, June 2011. DOI: 10.1130/G31818.1

Image: Wikimedia Commons / Dimorsitanos

CATEGORIZED UNDER: Environment, Human Origins
  • Torbjörn Larsson, OM

    Or the most likely explanation: coincidence. It would take a long series of published and verified claims before one can pronounce knowledge. (Whether today or in history.)

    [Hmm, what does it remind me of? … oh, yes, science. Doubt they had much more than luck to stand on. Geography wasn’t geology.]

  • Felesakis Stelios

    I think Stravo knew pretty much what he was talking about since it was not the first time he wrote about this phenomenon. In his book “Geographika” he describes the exact same think happening to a group of small islands called “Εχινάδες” at the east side of Zakynthos and Kefalonia in the Ionian sea.

  • Amos Zeeberg (Discover Web Editor)

    Wow, thanks for the info, Felesakis. But you’re right, Torbjorn, that by itself, this one “prediction” might well be a lucky guess.

  • Lee

    It should not surprise us that he could theorize that the peninsula had been an island. The Greeks were very astute.

  • James Morgan

    My mother as a child, back in the 1950’s, remembers that area and Kalitheia having fresh water marshes, so it is very possible that even in the 1st century B.C.E there were still marshes just as there was in the 50’s! After all it wasn’t until the 1960’s-70’s that both rivers in Athens were covered and controlled to change the local landscape. It is quite amazing how quickly an environment can change due to human interference and how quickly things are forgotten. So this may be one other option to his accuracy to consider.

  • James Morgan


  • reidh

    Maybe Some people had drawn a map?

  • Dwight E. Howell

    Why does anyone think he was doing much guessing?

    He was intelligent. His people were literate so at least some data about observed changes in his environment could be based on those limited records plus he could have asked the locals about what their traditions said about local changes. He goes to a land mass with a name suggesting it was an island. He can see a narrow neck of lowland/ marsh with little relief between the former island and the mainland. He’s pretty much going to know that such locations are sediment traps and that before that marsh/lowland was filled with sediment the place would have been an island.

    Learning some things requires high tech, detailed histories of long ago events, and modern day science. Figuring out others requires little more than a working brain and observation plus perhaps a few old storeis and limited written records and this is clearly in the last camp. Once you understand the location is a sediment trap all you have to do is mentally remove the sediment to understand what the location was like in the past.

  • Mitch

    Uh, maybe he just dug up some shells or other water based fossils where land now stood? I’m not a geologist but every time I see fossilized shells in the soil around me I have to suspect that at one time the area I live in was under water….

  • Bromios

    How did they ancients know so much? Must have been a lot of lucky guesses if you listen to articles like the above. The scientific methods of the last sixty years are in many cases unrealistically lab focussed. In comparison was the Greek method of proper observation . False reports of Greek dislike of experimentation and practical applications are not true, but left overs of English Christian nineteenth century translations. Heliotropism, exempli gratia was observed by Pythagoras and Plato.

  • http://- Philippa Doran

    Look what has happened at Troy over 3,000 years. The bay is now completely filled in
    Would it be by sediment from Scamander and Simois over the millennia?
    How much of that had happened by Strabo’s time? Did he know that it was happening?
    That might have given him a clue.

    There could have been another change in coastlines after the Thera eruption. That must have caused huge tsunamis. Northern Crete would have been right in their path.
    Athens is on the Eastern coast of Greece and could well have been affected too.
    But one would suppose that a large tsunami would wash out a land bridge, not create one, unless it piled up the sea bed in shallow water.

    Have any studies been made of possible coastline alterations at that time?

  • Suz

    I once was driving down a country road in central Texas with a family friend. I asked him if he knew why the trees all leaned toward the west. He was dumb-struck. He had lived there 47 years, his whole life, and had never noticed. I think people pay attention to different things and it may be difficult to acknowledge someone else’s gifts just because they are different than our own.

  • Jazz

    WHY does every generation believe that those who came before couldn’t Possibly be as smart or clever as they are?! Obviously, we are wrong to think that- it is proven time and again that the “ancients” knew as much or more about their immediate surroundings as anyone today does. They OutDid us in many ways…..yet still we malign or label lucky the ones who laid down the learning pathways we still follow.

  • Jean-Philippe

    Your remarks are very interesting.
    If you want, let me your email adress and I will send you the paper of this study in PDF format


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