Elise Koskelo, winner of Best in Show at this year’s Science Fair, presents a talk about her project to members of the Kiwanis Club of Los Alamos March 8 at TOTH. Photo by Morrie Pongratz
Elise Koskelo, winner of Best in Show at this year’s Science Fair, visited the Kiwanis Club of Los Alamos recently to brief the organization on the latest developments in her project to understand how trees withstand earthquakes.
Club members listened intently as she presented a highly technical PowerPoint talk on “Why Buildings Need Branches.” They had good reason to listen: What she has learned could be useful as architects and engineers seek to build skyscrapers that can resist the shaking of earthquakes and keep residents safe.
Koskelo, 18, daughter of Aaron Koskelo and Jean Robinson and twin sister of Nick Koskelo, is a Los Alamos native. She is scheduled to graduate from Los Alamos High School (LAHS) this year, and she is looking at several colleges, thinking of studying engineering, geology, and archaeology. Her proud parents were both in the crowd as she spoke.
For her LAHS Science Fair project in 2015, she studied the cypress, the Scots pine, and the California redwood, and found that the redwood was the most likely to survive an earthquake because of its height, its width, and its drooping limbs.
This year, 2016, she took her research farther, using math and computer techniques to study just what happens to a tree when it is shaken by an earthquake. She built 3-D models of the California redwood, the Scots pine and the Patagonian cypress, and then conducted tests applying the seismic forces recorded during the 1940 El Centro earthquake and comparing what she found to the potential impact on the Transamerica Pyramid, a structure in San Francisco, which, at 853 feet, is the eighth tallest building in the world.
She hypothesized that the trees would experience shaking in separate modes and that the more branches a tree had, the more resistant it would be to an earthquake.
She used Fourier and modal analysis, and she did her computer coding in “Python,” which, she said, “I learned from scratch” for the project.
She found that at first, the “earthquake’s” shaking caused the entire “structure” of a tree to sway, but as the seismic force of the “earthquake” ramped up, she observed “individual bending” at each branch. There were different responses at different excitation frequencies. Above 500 hertz, individual branches moved out of phase with the core structure. The branches had a damping effect on the motion.
Her conclusion: “‘Branches’ should be added to buildings as dampers” because they can absorb some of the seismic shock from an earthquake.
Think of a tall building as a sort of tree. If it has enough “branches” to damp the effects of an earthquake, the people who live and work inside the “trunk,” have more protection.
After her presentation (which drew applause), her father said he is “very proud” of her. “She’s worked very hard,” he said. “This was a completely original project of her own devising.”
Her mother, Jean, commented that Elise has already had job offers as a result of this project. She said Elise is “an astonishing student and a wonderful daughter. I couldn’t be prouder of her and her many accomplishments.” She noted that in addition to her work in science, Elise is “an outstanding writer” and a very creative fiber artist.
She’s also vice president of the LAHS Key Club this year.