University Park, Pa. -- Finding the geographic center of Pennsylvania should be easy as drawing an X over a map, right? Not necessarily because a variety of factors -- history, geometry, geography, the accuracy and precision of the data and the methods used -- can influence the yardstick and, therefore, produce different answers, according to Penn State geographers.
"We are confident that the center is located in Centre County, but it is very difficult to be definitive about its exact position," said Mark Gahegan, professor of geography and associate director of the GeoVISTA Center.
"Our estimate is that the geographic center falls close to, and west of Spring Creek, between State College and Bellefonte, near the state fish hatcheries and just below Fisherman's Paradise," he said.
In response to a request from Penn State President Graham B. Spanier, Penn State geography researchers applied mapping technology to find the exact geographic center of the commonwealth.
Penn State lore has long held that the sundial in front of Old Main on the University Park campus marks the epicenter of the commonwealth -- something cartographers have recently disputed.
Another historical claim more grounded in scientific study places the center in the village of Aaronsburg -- but the shape of the state at the time of the claim made in 1786 did not include Erie County.
"It wasn't until the 19th century that the state assumed its present outline, and the additional land acquired would make a difference in the calculations, as would improvements in surveying, cartography and the availability of computers to provide an analytic solution" Gahegan noted.
The Penn State geographers plugged into their computer-based GIS models existing state outline data, which broke the state down into a large number of simpler geometric regions and calculated the center according to the weighted sum of all these regions, but since the accuracy of the state outline is probably not consistent, it is not possible to be exactly certain as to where the center falls.