Digging Digital Data

Revisiting the Penn Museum Expedition to Sybaris

By: and Kacie Alaga

June 21, 2021

Over the course of the past year I had the opportunity to work on a Museum Assistantship project with Dr. Jason Herrmann titled Digging Digital Data: Revisiting the Penn Museum Expedition to Sybaris. In the early 1960s the Penn Museum partnered with the Lerici Foundation of Milan to conduct a series of geophysical surveys in an attempt to discover the site of the ancient Greek settlement of Sybaris in southern Italy. This was a significant undertaking as it represented one of the earliest large-scale uses of remote sensing technology applied to archaeological field work. The focus of the Digging Digital Data project was to digitize the data collected from these early geophysical surveys in order to make the information more accessible to researchers and educators, as well as to take advantage of modern GIS technology to facilitate improved data display and capability for spatial analysis.

Map of Sybaris, at the tip of the Italian peninsula. Image from “The Search for Sybaris”, by Froelich Rainey. Expedition Magazine 11.2 (1969): 10-13.
Given the COVID restrictions faced by the University and the Penn Museum, I was fortunate to be able to work on this project remotely and independently while consulting virtually with Dr. Herrmann. The first phase of the project involved digitizing the handwritten survey data recorded by the original archaeological team. The Penn Museum archivists were kind enough to scan all four field notebooks associated with the Sybaris project so that I had access to the data. I began by transcribing each page of data, representing a series of readings collected from magnetometry or electrical resistance surveys conducted at the Sybaris site, into individual Excel files. Any metadata associated with each data set, such as the date of the survey, the name of the surveyor, or the location of the survey, were recorded in a separate file that can be utilized by future researchers.
Example of handwriten data grid. Penn Museum Archives.

Once each page of handwritten data was copied into an Excel file, the files were saved as tab-delineated text files for further formatting. These text files were formulated and converted to Surfer grids in preparation for uploading as raster images into a GIS. For this project I utilized the ArcMap program, which is part of the ArcGIS suite. As a raster layer, each grid of data from the field notebooks was translated into a series of square cells, with each cell representing a data value. By manipulating the display properties within the GIS it is possible to assign each cell a color, based upon a greyscale gradient, in which the highest data values are represented in white and the lowest data values represented in black. The resulting gradated images illustrate how the digitization of these data values is translated into visual displays through the use of a GIS. These images provide a clearer understanding of the geophysical data collected at Sybaris, and can also facilitate improved capacities for analysis of the data.

After creating raster images of each data grid and uploading those to the GIS, each survey grid will be georeferenced so that it can be projected accurately and overlaid onto an aerial map of the Sybaris site. Ultimately, joining all the disparate survey grid images together into a single spatial feature that can be viewed in conjunction with the landscape surrounding Sybaris will enable an enhanced capability for spatial analysis by overlaying the geophysical artifacts and anomalies with the corresponding natural features of the site. This visual display will increase the utility and value of the collected data sets for future researchers and educators who choose to engage with the Sybaris project. Going forward I will be assisting Dr. Herrmann in preparing an article detailing the digitization process of the Sybaris data for publication in a peer-reviewed journal.

Aerial imagery of Sybaris. Image from “The Search for Sybaris”, by Froelich Rainey. Expedition Magazine 11.2 (1969): 10-13.

Though I had gained some previous experience through classes at Penn in geophysical prospection methods and the use of a GIS as a tool for spatial analysis, I was excited to participate in the Digging Digital Data project as a way of expanding my knowledge and skills in these areas and gaining additional practice with the technologies involved. I particularly enjoyed the opportunity to engage with legacy data from past Penn Museum field work and see how far technological advances in the practice of archaeology have advanced and improved conditions for research and analysis of information. As I begin working towards my PhD in the field of digital archaeology this fall, the skills and experience I gained through participating in the Digging Digital Data Museum Assistantship, particularly the opportunity to publish as co-author in a peer-reviewed journal, will continue to support both my academic and professional goals.

Kacie Alaga is an MA student in the Art and Archaeology of the Mediterranean World program. She is one of several Museum Assistants selected for the 2020-2021 academic year. The Museum Assistantship Program offers paid opportunities for University of Pennsylvania graduate students to work on unique projects within the Penn Museum. The program pairs Museum projects in need of research assistance with skilled graduate students from related fields.