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The Ground Beneath Joyce: What Science Reveals About Her Captivity at Six Flags
For decades, Joyce has lived in captivity. Since 2010, she’s been kept at Six Flags Wild Safari in New Jersey, in an enclosure alarmingly close to the park’s roller coasters and heavy vehicle routes. That’s especially troubling for an elephant, given how sensitive they are to even the faintest ground vibrations.
For example, elephants use low-frequency rumbles through the ground to communicate with one another across great distances. But at Six Flags, Joyce is constantly surrounded by man-made vibrations: rollercoasters, trucks and heavy machinery. So to better understand what she experiences, World Animal Protection partnered with Terrapin Sensing and the University of Maryland Department of Geology to measure the intensity and sources of ground shaking around Joyce’s enclosure.
What the Data Shows
Between July 12 and August 12, 2025, sensitive seismometers were placed at eight sites around Six Flags’ amusement and safari parks. After 30 days of collecting data, the results were clear: Joyce’s environment is full of constant and powerful vibrations.
The seismology readings found three primary sources of ground motion:
- Rollercoasters producing vibrations between 5 and 20 Hz, which is the same range elephants naturally use to communicate.
- Safari trucks driving through the park, generating frequent vibrations between 20 and 200 Hz.
- A nearby water treatment plant, creating a steady mechanical hum around 7–10 Hz.
On the Mercalli Scale, these vibrations correspond to roughly a Level IV to V, which is similar to the tremors felt during a small earthquake. That means Joyce isn’t just sensing these vibrations, she’s living in a world where the ground is persistently shaking beneath her feet.
Why This Matters
While the seismology instruments were designed to measure vibrations as humans feel them, scientists still don’t fully understand how elephants perceive or are affected by such constant ground motion. What we do know is that elephants are acutely sensitive to low-frequency vibrations and rely on them for comfort, communication, and safety. For Joyce, being exposed to these daily artificial vibrations likely disrupts her natural sensory world, compounding the stress of captivity.
“Elephants in the wild may choose to avoid such vibrations, but in captivity they have no such choice,” Dr. Jan Schmidt-Burback, World Animal Protection’s Director of Wildlife Research and Veterinary Expertise, said. “This adds to the long list of concerns for why a theme park in a cold climate environment, with truck-based observation on roads and rollercoasters nearby is clearly not the right environment for elephants such as Joyce.”
What’s Next
These findings underscore the urgent need to relocate Joyce to a sanctuary where she can finally live in peace, free from the constant mechanical noise and vibration she currently experiences at Six Flags. World Animal Protection will continue to work with experts and advocates to ensure her suffering is not ignored.
Sign the Petition
Join us in demanding Six Flags release Joyce and the other elephants to sanctuaries and close the elephant exhibit for good.