Renowned archaeologist Franck Goddio talks with podcast host Steve Mirsky (pictured) about his efforts to recover artifacts from the ancient cities of Alexandria, Heracleion and Canopus, with special attention to discoveries related to Cleopatra and her reign. The exhibit Cleopatra: The Search for the Last Queen of Egypt opens at the Franklin Institute in Philadelphia on June 5th. Web sites related to this episode include www.underwaterdiscovery.org 

Podcast Transcription

Steve: Welcome to Science Talk, the weekly podcast of Scientific American posted on January 31st, 2010. I am Steve Mirsky. This week on the podcast …

Goddio: What we are doing is not underwater archaeology, it is land archaeology underwater.

Steve: That's renowned archaeologist Franck Goddio, who visited Scientific American last week. He spent almost two decades working in Egypt in the Bay of Alexandria attempting [to] map the Portus Magnus, the great port of Alexandria, one of the most important cities of the ancient world. And in nearby Aboukir Bay, he searched for two cities that he believed were submerged there, Heracleion and Canopus. As youll hear, he was convinced those cities should be there, based on the publications of some authoritative writers including Herodotus, Strabo and Julius Caesar. Much of what Goddio has found is related to Cleopatra and will be on display starting in June at the Franklin Institute in Philadelphia. The exhibit is called "Cleopatra: The Search for the Last Queen of Egypt," which will then travel around the U.S. We'll have more info on that as June approaches. Right now, let's listen as Frank Goddio describes his work. You'll also hear me, Scientific American's Kate Wong and Mark Lach with Arts and Exhibitions International, which is putting together the Cleopatra exhibition.

Goddio: Well, I have always been fascinated by archaeology, history since I was a kid, so I had always in mind that one day I will do archaeology, but I didn't start like this. I studied math and statistics and was [an] advisor to foreign governments for [a] few years at an international institution, at the U.N. And then finally one day I decided to take sabbatical and to go serious and to be serious, and I started archeology. And we started the project in '92 in Egypt, by [a] geophysics survey, which lasted six years, in the Bay of Alexandria and also in the Bay of Aboukir. The purpose in Alexandria was to try to map what had been the Portus Magnus, the great port of Alexandria in the antiquity, which was the biggest port of its time. And in Aboukir Bay, I was convinced that were located two cities, which had never been discovered on land, and I was absolutely convinced that they were submerged under the sea. I took the decision, tried to locate them, map them and tried to identify them.

Steve: What were your readings that made you believe that those cities were there?

Goddio: We are very, very fortunate because for Alexandria, the city of Canopus and the City of Heracleion, the City of Tanis, we had the best of sources: Herodotus, Strabo, Julius Caesar, not so small a one. And speaking about writing about cities, the Portus Magnus, or the city of Heracleion, which for example, Herodotus visited in 450 B.C., he went there, he entered the big temple and he described it as a temple to Heracles and gave lot of information about that time. Then lot of fossils, we're speaking about the writing about Canopus, the famous city of Canopus, the big temple of Serapis in Canopus, which was one of the most important temple[s] to that god with one of Alexandria. And of course in Alexandria we have the big amounts of description by Strabo, by Herodotus, by Julius Caesar about the [royal] quarters; about the temples and palaces. Thus for Alexandria it was easy, you know, there were archeological site[s] on land which ha[d] been identified and it was obvious that part of the city was missing and that part had to be underwater. Thus there it was clear there was the bay of Alexandria, you had to perform electronic survey or physics survey with nuclear resonance magnetometer, multi-beams, echo sounder and sub bottom profiler, etcetera, in order to try to identify electronic signals and then perform archeological excavation in order to characterize those signals. And after a few years of work at the bay of Alexandria, we had electronic maps, and we started to perform the sounding, archeological sounding and when we started, it went very, very fast. Once we had the electronic map, we characterized all the submerged land or submerged port infrastructure very easily in two years and we found the Portus Magnus, the big port of Alexandria in two years after the survey, means seven to eight years. We came up with the first comprehensive map in 2000, and we're adding more details to it, of course, every year. For Aboukir Bay, it was a nice change because, there were three cities mentioned in the books, Heracleion, Canopus and Tanis. In the 19th century, they named ruins found on the coast by those [names] but archeological excavation performed on that site never brought a single clue [that] they were correctly identified. We performed with my team that survey in Aboukir Bay. We got electronic signals, but I was very concerned that those electronic signals were very far from the present coast of Egypt—seven kilometers away. I [thought], seven kilometers, to find a city seven kilometers away from the present coast seems, [a] little bit kind of a dream. But we started to excavate in 2000 and we came across very fast, a very big structure, a monument, which was a temple. We started excavation, we found intact still a hieroglyphic inscription telling us, "you're in the city of Heracleion", and we found foundation deposit, we were at the temple of Amun and [his] son, Khonsu, which were known to be the temple of Heracleion from a [stela] found in the 19th century saying that this city of Heracleion was the city who possessed the temple to Amun, and we found this [stela] saying you are at the temple of Amun-Re. Yes, it was kind of unbelievable. Then we went on excavating, excavating, we found another sanctuary, we found a living quarter, the port, you know, and we have not yet completed the map of Heracleion, which was the biggest port of Egypt before the foundation of Alexandria, and according to the text, and this is confirmed by what we found in situ and written on [stelae] on black granite, it was the city where all boats entering Egypt should stop, pay custom duty and then they could enter to the land and go to Egypt. Thus it was a very big city with a temple to Amun which has a peculiarity. It was a temple, where all the new pharaohs had to come in order to receive the title of the Apollo from the supreme god, Amun. Thus it was a very important city. Its only when Alexander the Great, came to Egypt that he decided to found a new city, Alexandria, and he ordered—we have the texts for that—that all the trade from Heracleion should be transferred to the new city, Alexandria. Thus, Heracleion is the pharaonic city, but very important during the Ptolemaic time and during the time of Cleopatra because she had to go to the temple to be pharaoh. When the new pharaohs, after the death of the old pharaoh was coming to the temple, he received from the priest of Amun, a kind of cylinder, and in that cylinder there was inventory of every thing existing on land and in the sky; and by taking this cylinder called the mikus, this man or this woman became the universal sovereign—[the pharaoh]. And then she or he was going out of the temple in a big ceremony and were going back to Alexandria.

Steve: Very helpful when they actually label the artifacts for you.

Goddio: I would have said this, everybody would have said, okay the guy is totally nuts, he is naming it, but now I have the concrete, I have the big stela intact, the rest of it intact...

Lach: It could have said Frank, [you] found it … the rest is there. Congratulations.

Goddio: Let's all note down this.

Steve: So how do you account for the, was it seven kilometers?

Goddio: This, we've done [a] geological survey with the Smithsonian Institution of Washington in order to assess why all those salinities appear under the sea and under the city; because if you dive, you see nothing but sediment—you have one to six meters of sediment above all [that remains] today. It's a conjunction of phenomenon as the main phenomenon is called the liquefaction of land. The delta is made of clay. The clay has in its structure water trapped into crystals. If you exercise a pressure above the critical pressure to that clay, the crystal will go [parallel] [to] each other and water will be expelled and as the clay had 50 to 60 percent of water in its structure, the clay will lose, the ground will lose 50 percent of its volume. That means a big temple built on clay is exercising a big pressure on its weight; an additional weight coming from tsunamis or a catastrophic flood of the Nile—but most probably a tsunami—will trigger that phenomenon, and the temple and all other construction around will sink few meters in a fraction of a second. And this we were able to show by the reading that we've done that this has happened several times during history. One time just after the visit of Herodotus to that city and before the coming of Alexander the Great to Egypt. And [another] time of second century B.C., and a third time, the most devastating one, on the eighth century A.D. And that last, I think, most probably seismic event, which triggered that land liquefaction destroyed Heracleion, Canopus and the Portus Magnus of Alexandria at the same time. And by the way I forgot that the city of Tanis which was mentioned by Strabo—Strabo made a visit there, visit to Heracleion, went there and saw, "Oh, the inhabitants are telling me that once upon a time, about 29 B.C., once upon a time, there was a city around called Tanis," and all the historians were saying, "Oh, okay, you say nonsense." I was commenting [that] nothing was nonsense and on this stela, well written, it's written Heracleion is Tanis, thus we know now something that Strabo having traveled to that place 2,000 years ago [didn't know].

Wong: And how when you're excavating underwater, I mean, [I've] been to terrestrial archeological excavations, and every shard of pottery, every piece of bone, the location that it is recorded in three dimensions, are you doing the same thing, every [coin] that you find?

Goddio: No, no, what were doing is not underwater archeology, it's land archeology underwater; it's exactly the same technique; it needs more logistics and there is a main difference is that on land you have the grid you start an excavation and you can go to from one square to another one and to another one and let those square[s] finish to see what [will] appear in the square close by. You cannot do this underwater. You have to do much more [thorough] work because in one day, the sediment will cover back the excavation you've done. And sometimes the visibility is so poor, 10 to 15 cm, you're working at that, that you have to register everything that you're seeing, that you have to photograph, position clearly, draw and then go to another the square. You know that when you come the day after it will be covered by the sediments. Thus it's a different type of technique, but more or less the same.

Wong: Right, right. Is the focus now mostly on you know reconstructing the life in times of Cleopatra specifically or, you know, where are the things right now?

Goddio: We're doing one mission a year, sometimes two missions a year, and up to now the main purpose was mapping, mapping and mapping, to have a clear idea of the topography of the Portus Magnus of Alexandria, Canopus and Heracleion-Tanis. Then after we enter more, it's like we focus, you know; you have to map this, you know that there is a submerged island; this submerged island you already found in Strabo, it's a name Antirhodos; okay, you're on Antirhodos. And on Antirhodos you have a palace, and he's talking three years after the death of Cleopatra. Thus Antirhodos is a very small island 300 meters, 50 meter wide, so you cannot miss much of it; thus going in the middle way you have an electronic signal, we found the foundation of a very big palace. And we knew there was a palace there three years after the death of Cleopatra. What we did not know for example is that on the [secondary] branch there was another building, which was a temple to Isis, which fit well. Thus this year, we will focus in Alexandria in working to that place, [the] palace of Cleopatra, mainly there. And but we're working also on other places in Alexandria, in order, in some place to identify the structure, in another place where it has been identified to characterize more precisely what type of a temple, is it a living quarter, is it a shipyard etc. In Heracleion-Tanis we're much less advanced than in Alexandria because the first city is huge—a two square kilometer city. The harbor covered two kilometers by 1.5 kilometers, and in the harbor up to now we have identified 63 ancient shipwrecks from the 13th century B.C. to the seventh century; we haven't started even one, you know. It's a huge, huge work. To give you an idea Pompeii has been discovered in the 18th century, they're still doing the excavation. And so now it's huge, huge and it's a small city. Here you're in the port of entry to Egypt, [with] is one of the important temple, which are 150 meters long by 80 meters wide, you know, one of the biggest temples in Egypt; and we need few centuries to excavate that, you know. Thus, we still have time [ahead of us]. Thus, this year, we will focus in Alexandria, in Cleopatra palaces on Antirhodos and in Heracleion-Tanis we started the excavation of one shipwreck as one team, and we characterize also part of this temple, which is very intriguing, a great temple to Heracles.

Steve: Without knowing anything, really about how do you do this work, I would guess that the technology that you employ today is far different from what you were using even 10 years ago at the beginning of the project? Is that [the case]?

Goddio: The technology or a piece of technology has improved a lot. The basic technology which allowed us to discover the site are nuclear resonance magnetometer that we have developed in the '90s for that purpose before starting this project by the Commissary of Atomic Energy of France. Its just a device to measure, they don't [give any] signal, just measure the magnetic field, you know, in one spot. And this enabled us to draw [an] electronic map, which for example can detect stone inside of clay or clay inside of sand. This is how we were able to pinpoint a long 3.5-kilometer signal between the city of Heracleion and the city of Canopus. And when we started excavation, we characterized it as a channel, which is the famous Canopic channel, which was used by all the pharaohs, and we have description of Cleopatra making [feast on that] channel. Thus that piece is exactly the same, what has improved a lot is the computer producing the map, you know. Fifteen years ago it was on paper, you know, then after we have a paper map and now we have a [server] program, for example, and GPS also, the centimetric GPS in one centimeter you know, in 3-D is helping us a lot. Even underwater, now we are able use that. Thus I would say the basic instrument, nuclear resonance magnetometer are the same, the sensors are the same, the computers, the process, you know, [the software] [it's] so powerful, with layers on the map, on the electronic signal you can [put] the bathymetry from the echo sounder or from the multi-beam and you can position the artifact with and you have the layers exactly, it's fabulous. What has been developed tremendously as a device is a multi-beam, which it's an echo sounder, but a kind of a 3-D echo sounder, with a centimetric positioning, you know—thanks to the centimetric DGPS—and this gives you electronic image of the button to a precision of a two to three centimeter. But something has to protrude from the bottom, otherwise you see only sand, but sometimes it's okay.

Wong: How far underwater are these sites?

Goddio: No, no this site, not in Alexandria between two meter[s] and 15 meters plus three to five meters of sediment that means five meters and 18 meters, when you take out the sediment. In Heracleion, 10 to 12 meter; in Canopus eight to six.

Lach: Do you blow the sediment away?

Goddio: No, we don't blow when you do an excavation …

Lach: Of course, [the small pieces].

Goddio: … because if you blow, you erase everything. Thus you have kind of suction, water suction, and you have the water hose as well, and you do that like that and a shard appears okay, you're up and you put a tag on it; and if you kind of put a tag on it, you have a net with a tag in the net and you put the shard in the net.

Steve: How many divers might be working on this site?

Goddio: The team is 55 in Alexandria and Aboukir. We have 12 divers, archeologists, diving two and half hours in the morning and two and half hours in the afternoon. Personally, I dive much less, though [everybody] me to dive much more because at least I don't take the report of the diver coming in, because when the diver comes to the surface, okay, very good, the report, so we go up to meet with them.

Lach: The boss is [watching].

Steve: How often do you actually go in?

Goddio: Once a day after everybody has dived, in order to see the site and say sometimes twice a day, if it's important, but not [two] hours; I go see the site, I see if we have to go on this track or change and …

Steve: Sounds like a lot more fun than being cramped up in a laboratory.

Goddio: Well [not always]; sometimes [the] water is very cold and sometimes the visibility is very poor.

Wong: Maybe you could tell us what's in this exhibit.

Goddio: Yes, yes. This exhibit we focus about everything which is related to the world of Cleopatra. That means, [until] [the] end of Ptolemaic dynasty 330 B.C. and 30 B.C. And we're there in the last century, more or less, because she died in 30 B.C. And we have, of course, a lot of artifacts coming from Alexandria, she was living there. What is strange with Cleopatra and this is known by historians since a long time—Dor political reason after her death, her images were erased. [And her hieroglyph name was erased]; [deleo ex memoria]—that means to erase her…

Steve: [Striken] from the memory.

Goddio: … from the memory. Thus you cannot expect to find a nice statue of Cleopatra. Let's forget about that; maybe there is somewhere. You do find coins with her profile, you know; interesting because people can destroy statue, but they will never dare to destroy a coin because it can be used, you know, which is good. But we have a lot of things related, closely related to her. For example, in the exhibit, we see a sphinx, which has been found in the temple of Isis, close to her palace on Antirhodos, and this sphinx is a likeness of her father. We have coins and also statue of her father and you see this sphinx [with] the likeness of father; which is strange you know, that, he[r] father was protecting Isis, and she was Isis, she considered herself as Isis. We have also a very moving piece, which is the head of her son, Cesario, and it's a colossus head of black granite. And we found that head just in front her palace but on the anti-coast, in a place, where we dig also this year, which we have not 100 percent proof in writing etc., because we have not written element but we have a kind of fossil proof showing us that we are excavating the temple of the Caesars, a temple that Cleopatra ordered to be build in honor of Julius Caesar. And when he died his temple was transformed to the Caesars and Ptolemy XV, her son, [with] Julius Caesar was the last of the Caesars in Egypt, the last of the pharaoh. And we have this beautiful head, which will be in the temple, we have coins and statues. But we have also daily life objects, you know, of Alexandria. And we have also everything from Canopus and Heracleion which concerns the devotion she had to [the] gods. And we know from [texts] that she was participating in paganism and [processions] in Canopus and in Heracleion, and we did find all the instrument of that cult and etcetera. You have the daily life, you have the riches of Alexandria, you have the details of life of that time.

Steve: The Cleopatra exhibit opens at the Franklin Institute in Philadelphia on June 5th. As that date approaches we'll have more from the hour-long interview with Franck Goddio and Mark Lach. We'll roll out the new quiz TOTALL……. Y BOGUS, in a separate standalone episode, coming soon. Till then check out Larry Greenemeier's coverage of the next big thing, Apple's iPad. It's like the large print edition of the iPhone. That's www.ScientificAmerican.com. You can follow us on Twitter where you'll get a tweet every time a new article hits the Web site. Our Twitter name is @-SciAm—S-C-I-A-M. For Science Talk, the podcast of Scientific American, I'm Steve Mirsky. Thanks for clicking on us.