I explored the spatial field of digital humanities this week through georeferencing. Through the David Rumsey Georeferencer page, I was able to overlay a historical map of the Mediterranean onto a modern map. You can see the two maps here.
The first thing I noticed when seeing this map overlaid with a modern map is that they don’t match up perfectly. The map can get more accurate as you add more reference points, however, the original scale is skewed in certain places. This could be due to differences in mapping technology, differences in the physical geology, or differences in the way it was mapped (ex: mapping on a spherical vs flat surface).
It was actually much easier to georectify the map than I thought it would be. When looking at other spatial DH projects, mapping looks very complicated and the amount of customization on fully finished projects is intimidating. Still, there are many ways to access mapping as a digital tool.
The David Rumsey Georeferencer was particularly helpful and allows you to access your georectified map in GIS Apps and GeoTIFF. You can also interact with your georectified map within the David Rumsey site.
I think it would be interesting to compare historical maps of the same area over different time periods and georeferencing could allow you to do that. You could look at multiple georectified maps in the Mediterranean to see the change in city locations, borders, or even shorelines. Compiling a lot of georectified maps could allow you to ask more questions and make more comparisons beyond comparing one map to the modern map.
One thing I would keep in mind as we move forward with this tool, is that the modern map that you are comparing things to is not completely objective or accurate. Geography is constantly changing and we must remember that people had to make certain choices in creating this map. This allows for subjectivity.
Finally, georeferencing can only really be used for maps of locations on Earth because we have access to so many iterations of these maps that can be compared to each other. There are many fictional maps that could not be compared to our modern map of Earth because they do not exist in this world. It would be pointless to overlay a fictional map on our map, if they have no geography in common.