What Science Reveals About Elephant Captivity at Six Flags

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 at Six Flags New Jersey.

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 the elephant’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.

“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.”

Read the full report and sign World Animal Protection’s petition demanding Six Flags release Joyce to an accredited sanctuary.