The Five College Digital Humanities Undergraduate Fellowship supports innovative digital humanities projects from a variety of academic disciplines including archaeology, anthropology, English, critical studies, computer science and more. In this blog post, Gwendolyn Ruth Jones (Smith College) describes her cutting digital archaeological project that innovates in the use LiDAR for a historical archaeological survey in the Western Massachusetts region. Read on to learn about Gwendolyn’s discoveries…
Uncovering a New England Ghost Town:
Using LiDAR to Visualize Archaeological features at Macleish Field Station
Gwendolyn Ruth Jones
Smith College Class of 2019
My goal for this project was to use LiDAR data to deepen my understanding of an archaeological site. I wanted to see what otherwise invisible information about archaeological features at MacLeish it could uncover. Light Detection and Ranging (LiDAR) is a remote sensing method which uses a pulsing laser to measure ranges. The subsequent point cloud is incredibly dense and provides a wide range of data. This point cloud can be used to create other geospatial models, such as digital elevation, canopy, and building models. This makes it possible to model archaeological features without disturbing or damaging a site that is difficult to reach or heavily damaged to begin with. Massachusetts has available LiDAR data from flights across the entire state.
Fig 1: USGS Map from 1895 courtesy of UNH Library http://docs.unh.edu/nhtopos/nhtopos.htm
In Whately, Massachusetts, Smith College owns 240 acres of wooded land. This ownership of this land changed hands many times before finally being bought by Smith College in the 1970s. I began my research by looking into the history of this land’s use and ownership. In 1871, James O’Connell leased a parcel of this land to Richard Moore “…for the purpose of searching for mineral and fossil substances, and of conducting mining and quarrying operations.” Galena (a combination of lead and sulfur, and a principal ore of lead) was known to exist on this property, and ownership of this property subsequently changed often as people attempted to profit off of the area’s geology. Maps from 1895 and 1909 (figures 1 and 2 respectively) each show residences on a road just west of Popple Hill called Hill Road. This road is now a path running through MacLeish field station.
Fig. 2: A map of Whately from 1909
Unfortunately, poor weather and a busy schedule have prevented me from going to MacLeish in person, but I do plan to be there most weekends over the summer once I have my own car. Luckily, a friend of mine has done previous research at MacLeish and was able to help me out. According to Emma Harnisch, class of 2018, there are three mines at Macleish. Two are fairly close to each other, near the modern field station, and the third is a bit further away up the hill. Figure three shows the locations of the mines on a Digital Elevation model I created from the LiDAR data and figures four and five show the mines as they were in the fall of 2016.
Fig. 3: A DEM I created. The two mines nearing the field station are circled in red. Near them tailing piles (piles of rock removed from the mines and stripped of the desired minerals) are also visible.
Using LAStools (a LiDAR data processing software) and ArcGIS I have been able to model the entirety of MacLeish. In order to do so, I first had to remove the vegetation from my data. I did so by filtering out only the ground and key points (stone walls, and other archaeological features) from each of the eight tiles. From these LAS files, I was then able to make multiple kinds of models, including digital elevation models (DEMs). After many calculations and much trial and error, I was able to make my DEMs as detailed as possible. Unfortunately, there are black lines running through each tile (visible in the figures below) which I have not yet figured out how to remove. I am also currently in the process of using LASview to visualize the data in other ways. In the hillshade digital elevation models, I have come across what I think may be the remains of a homestead on the portion of MacLeish often referred to as the Todd lot (fig. 6). This homestead is now nearly invisible when walking through MacLeish unless you already know where it is.
Fig. 4: The mine closest to the field station (the easternmost mine). Photo by Emma Harnisch. Class of 2018
I am very excited for the future of this project. I am in the process of writing a research paper on historic landscape ecology in Massachusetts and the application of LiDAR to both landscape studies and research of archaeological features in the Massachusetts forests. Over the summer I will be visiting MacLeish most weekends in preparation for my senior thesis, in which I will be doing surface collection and documentation of a few of these archaeological sites. I will use photogrammetry (the use of photography in mapping, measuring, and modeling) to create a three dimensional model of the homestead and the two mines (seen in figures three and six) in addition to what I have been doing with LiDAR. I am in the process of finding the necessary equipment to also use ground penetrating radar (GPR) on the two mines and the tunnel between them. GPR, similar to LiDAR, pulses high-frequency radio waves into the ground which, using the distances between the device and objects off of which the waves refract, creates an image of what lies beneath the surface. This non-destructive method could let me visualize the mines and their tunnels without having to dig into them. Smith College has also recently acquired another homestead I plan to study, and I look forward to applying what I have learned about LiDAR to that plot of land.
Fig. 5: A trench which may indicate a collapsed tunnel that once connected the two mines. Photo by Emma Harnisch. Class of 2018
Fig. 6: A rectangular feature (circled in blue) I believe could indicate the remains of buildings from the 18th century.
Fig. 7-9: Three DEMs of MacLeish. Note the many stone walls all across the property.