Environmental seismology often surfaces in the most unexpected places. A recent study by faculty from the University of Maryland's Department of Geological, Environmental, and Planetary Sciences used seismic monitoring to address a non-traditional challenge (i.e., not earthquakes): investigating ground vibrations around an amusement and safari park in New Jersey. The study explored whether nearby roller coasters impact the acoustic and seismic environment of Joyce, a resident African elephant at the safari park – a critical question given that elephants are highly sensitive to low-frequency vibrations (Poole, 2011).
To evaluate the local vibration environment, Associate Professor Nicholas Schmerr and Assistant Research Scientists Jackie Clark and Hannes Bernhardt deployed seismic sensor nodes at eight sites around the parks during the summer of 2025. The site locations were selected to compare vibration levels near the roller coasters, the elephant enclosure, and other potential sources such as public roads and a nearby water treatment plant. Continuous monitoring over a one-month period allowed the team to separate short-lived events, such as earthquakes and isolated weather events, from persistent daily patterns.
The GEPS team identified three primary sources that dominate the local ground-motion environment: vehicle traffic, the water treatment plant, and roller coasters. Near the elephant enclosure, the strongest vibrations were associated with the safari truck traffic, which produced the highest average vibration levels at the closest stations. The water treatment plant generates a steady, low-frequency signal around 7–10 Hz, but it weakens substantially with distance and drops to weak or nearly imperceptible levels near the enclosure. Roller coaster vibrations were clearly measurable, especially at stations closer to the amusement park, and were concentrated mainly in the 5–20 Hz range. Near the elephant enclosure, however, roller coaster-related signals were generally weaker than those produced by the safari trucks.
The study also revealed pronounced daily patterns linked to park operations (Figure 2). Roller coaster signals began before the amusement park opened, while safari-related activity was concentrated during daytime operating hours. These recurring patterns demonstrate how passive seismic monitoring can be used to track human activity and infrastructure effects in a complex environmental setting.
However, a critical caveat of this study involves the interpretation of the biological impacts. The vibration metrics used in this study are calibrated for human perception (i.e., the Mercalli scale, Table 1) and may not reflect elephant physiology. Research on elephant communication suggests that these animals use low frequencies (~10 Hz or less) to detect and communicate with other herds (Poole, 2011) and are sensitive to ground vibrations passing through the ground. Most of the park-related vibrations fell within the 5-20 Hz range, which humans can easily detect. Still, the specific effect on an animal with sensitive hearing, like Joyce, remains uncertain, underscoring the need for further research.
While the seismic data indicate that roller coasters do contribute to ground motion, the primary source of seismic activity near Joyce the elephant is the large safari trucks in the safari park. For the GEPS Department, this study reflects the breadth of modern geoscience, demonstrating how quantitative methods intersect earth science, animal management, and civil infrastructure.
References
Poole, J. H. (2011). Behavioral contexts of elephant acoustic communication. The Amboseli elephants: a long-term perspective on a long-lived mammal. Chicago: The University of Chicago, 125-161.