I am writing this on Saturday early afternoon, June 27th. Over the past two days we continued data collection and analysis. As of 6 PM local time Friday (last night) we shut down data collection and have moved into the intense data analysis phase. I need to come clean that the phase of the project we are in for the next two days is a bit less intense. Because of the long days with over 16-hours of daylight given our latitude of nearly 55 degree north, we have regularly been putting in 14-hour days in the field. The data compilation phase we are in now is much less intense. Along this lines I write this blog at a street side cafe consuming a fine beverage. The evidence is below.
Now onto what we accomplished Thursday and Friday. I last blogged Thursday afternoon. On Thursday we continued to collect GPR data, as well as spatial data for the creation of maps and diagrams related to the research. It may be useful at this point to provide a rundown of what we have been doing in terms of geophysics and mapping. Today I will also provide an overview of some of the connections we have made in terms of future research and collaborations. Regarding the GPR data collection, six grids have been completed. Before I provide the review, I want to provide the newest version of the map because it presents the preliminary information for the location of the grids. Here is the newest version of the map. Again, this is just a “field” working version, that will be refined and will be one of many maps and diagrams created based on this body of research. This is the forth “field” version and I already have enough changes to complete a 5th version. When I return to Duquesne, over the coming weeks and months, I will create many more versions and numerous other map products.
Now, here is the review of the grids. Grid #1 is on the south side of the contemporary school that is now on the Grand Synagogue site and it was deliberately located at a place where excavation took place in 2011. By strategically locating this grid it provides data for a location where we have a good idea of what is already located in the subsurface. In this way we can assess how well the equipment is working, and any limitations to data collection projected over the entire site. The equipment performed very well and we could see down to a depth of nearly three meters. What we could see on the plots created from the data is what we expected based on the 2011 excavation reports. Below is the GPR Slice plot. What is depicted are slices down through the data (top screen left) to the deepest penetration of the GPR signal (bottom screen right).In terms of depth in the lower right we can actually see to a depth of over four meters. The features at show up in the towards the bottom of the slice at the deeper depths are a set of steps entering the synagogue, that we excavated in 2011. Upon completion and analysis of the excavation, it was filled with sand with local soil then place at the top of the infill material. It appears that the GPR signal is able to pass to greater depths through the sand, compared to the native soil found at other grids in the study area. The data collected from grid #1 was invaluable in assessing instrument function.
I discussed grid 2 a few days ago, but her is a brief restating of the importance of this grid. It clearly shows structure (interpreted to be walls) beneath the surface that are converging at right angles. These features definitely have the possibility of being buried walls left behind when the Soviets destroyed the synagogue in the 1950’s. The two slices that most clearly depict this feature are again presented below.
Data for Grid 3, which is on the north side of the contemporary school is still being processed and I will discuss those when they are ready. Grid 4 and 5 have been processed and I will discuss the details of those grids and their significance now. The data for Grid 6, the final grid, is currently being processed by Geo-Slice in California. Below is the plot for grid 4.
What is important about grid four (again keeping in mind it is located on the north side of the school) is in some respects what you do not see. Take note of the slices in the middle and bottom rows depicted above and notice the whitish streak across the slices. This is interpreted as the walkways that existed between the now destroyed synagogue buildings. There is no signal at these locations indicating structures of the debris from destroyed structures because they did not exist at the first place at these locations. Towards the bottom of the slices deeper below the land surface may be rubble from the destroyed synagogue buildings. The data from these areas will undergo a more detailed analysis to determine the more precise nature of the materials.
What is interesting about the data from grid 5 are the features that are very consistent through the slices from near surface to depth. Also of interest are the areas that appear whitish that run the length of the slices in the top row of slices and through most of the middle row. This means that the feature (or as previously discussed the lack of any features) is consistent from near the surface to a depth of approximately 450 cm. Also of interest are the features that appears as the yellow and red anomalies both towards the top and bottom of the slices from near the surface to depth, which in this case is over six meters.
Lastly, I want to discuss where we are with this project and where we go from here. The GPR data collection phase at the Great Synagogue site is complete. All of the data and interpretation, and any related maps and diagram I create, will be turned over to Jon Seligman from the Israel Antiquities Authority as he plans for future work at the site. His intention, as I understand it, is to do a full excavation at the site and to find funding to complete a full (or partial depending on the amount of funding) reconstruction of the synagogue. We will not be part of that project. Instead we will pursue other projects with local collaborators. Meetings have been occurring between our research group and officials from the Museum of Tolerance, and the local Jewish community regarding future projects. One will occur at the woods of Pannarai, which I have previously discussed. Another may be associated with the Jewish cemeteries that have been destroyed and in some cases fully or partially relocated during the Soviet period. These discussions are ongoing at this point to refine the details. Also, as previously discussed, I have set up, which at this point can be called an understanding, to work on a DNA project involving a Neolithic Archaeological site near Vilnius. More details about that project, and the relationship we establish between Duquesne, the Forensic Science and Law Program, and the Lithuanian researchers will be forthcoming. As will details about future possibilities for student and faculty exchange.