The historic 2011 tornado outbreak in the South, combined with Bullion's social media effort, represented a unique opportunity for the new study, Knox said.
On April 27, 2011, more than 120 tornadoes caused more than 300 deaths across the South.
The items studied from the 2011 outbreak represent "just a small cross section of debris that just carpeted the Southeast," said Knox. "What was amazing was that there was so much debris that went so far."
An earlier study on tornado debris by Snow and his colleagues identified only two objects that had traveled more than 135 miles. By contrast, the Georgia study identified 44 items that traveled a comparable distance or farther.
The nearly 220 miles covered by the landscape photo sucked up by one of the Alabama tornadoes rivals the record path taken by a canceled check from Stockton, Kan., on April 11, 1991. The check was carried 223 miles from Kansas to a farm near Winnetoon, Neb., according to the World Meteorological Organization.
Robert Melcher, now 77, recalls finding the check while he repaired fences on his farm near Winnetoon. He returned it to the Kansas bank, and later received a letter from its owner, Ernestene Swaney, whose home near Stockton had been hit by a tornado. She thanked him and inquired whether he'd found any items from her collection of Elvis Presley memorabilia, Melcher said in an interview. The check was the only item he found.
In the Georgia study, Knox and his students categorized the items by weight. Among the heavier items, a Hackleburg Panthers cheerleading jacket flew from Hackleburg, Ala. to Elkmont, Ala., a distance of just over 66 miles.
Many of the items held deep significance to their owners, such as the metal sign that used to hang above the bleachers of the high school football stadium in Smithville, Miss.
The sign was a tribute to former Smithville marching band member Lee Frederick, who had died of bone cancer in 1998. It was found in Russellville, Ala. — approximately 50 miles away — about a month after one of the tornadoes destroyed Smithville High's stadium and much of the town.
Knox said the response from his students, who became co-authors of the research paper, was phenomenal.
Knox said he sought to teach them how to conduct the research in a way that was ethical and sensitive to the victims since the tornadoes destroyed lives and homes.
"Hopefully that's a message that the students will take with them," he said. "In this case, we had people whose houses were destroyed and the family members killed and the only thing they may have gotten back was a picture of Grandma and Grandpa that went 150 miles into another state."