A geophone on its own has little visual appeal. It’s merely a small magnet suspended within a coil of wire, akin to the components of a low-cost microphone, designed to respond when the ground beneath it moves. You can purchase one online for just a few dollars. When it’s sitting idle, it does not track anything of significance.
What transforms a geophone into a genuine scientific tool is everything surrounding it: the casing, the circuit board that interprets its signals, and the software that determines if a disturbance is caused by a passing vehicle or an earthquake. This aspect typically belongs to a well-funded lab, rather than a teenager’s bedroom.
Vivien He assembled hers in her own bedroom. At the age of sixteen, as a junior at Palos Verdes Peninsula High School in Southern California, she completed the project much like many ambitious undertakings of 2020: alone, at home, while the world was in lockdown. The resulting device costs under $100 to produce, fits comfortably in a hand about the size of a Rubik’s cube, and has been performing its intended function flawlessly ever since.
I am neither an engineer nor a scientist, and much of what occurs inside a functioning seismometer exceeds my ability to explain authoritatively. However, I can follow the narrative’s outline, which is compelling: a regular teenager, a collection of components purchasable with a part-time job’s paycheck, and a device now discussed alongside those made by established seismology laboratories.
The inspiration stemmed from a research article, not an emergency. During the early lockdowns, seismologists observed that the planet had become quieter, literally, as there was less human noise traveling through the earth due to fewer vehicles on the roads and reduced commuting. She read about this seismic silence and became intrigued by the possibility of measuring something similar herself. “I was curious if I could measure that from my own home,” she reminisced, “and that quickly evolved into, I wonder if I can measure in my home and apply it to earthquake early warning?”
This is a significant leap for a high school student to take independently, from noting an intriguing data point to deciding to construct a functional early-warning device. She lacked formal training in electronics or programming—the skills her project demanded—and no class was prepared to offer her the knowledge needed. Her approach, as she describes, involved researching incrementally, just like any inquisitive teenager might self-learn an unfamiliar skill using the internet, one search at a time until everything clicked.
Her workshop was a section of her bedroom, filled with assorted wires and geophones, and she also utilized a bathroom down the hall that had better lighting for soldering. Laser-cutting the acrylic case required moving a table into the backyard, with her dad present as a safety measure, which proved to be a wise decision. During one soldering session, a small fire started, which she requested her family keep from her mother.
She powered up the completed device for the first time one night after midnight in September 2020, then went to sleep. The next morning, Los Angeles experienced an earthquake, which her seismometer successfully recorded. “Then I went to sleep, and the following morning I woke up to news of an earthquake in Los Angeles, and I thought, oh, it’s fate!” She compared her instrument’s waveform to a nearby U.S. Geological Survey station located close to her house and discovered that both traces were in sync.
That initial detection was not a coincidence. By the subsequent spring, her device had registered every earthquake above magnitude 3.0 around Los Angeles since she activated it, providing users with a warning of a few to several seconds before the shaking commenced—ample time to take cover under a table, step back from shelves, or, in commercial environments, to automatically shut down equipment. Capturing small local earthquakes is notoriously challenging; they occur too frequently and are often too localized for large national systems to accommodate, and they tend to be too faint for most consumer devices to detect above ambient noise. Achieving a streak without missing any, on hardware she designed herself, is what working seismologists found compelling.
They certainly took notice. She presented her findings at the Seismological Society of America’s 2021 annual meeting and was the sole high school student that year to be awarded the organization’s Student Travel Grant. One of the researchers she had studied while self-educating in the field was Richard M. Allen, director of the Berkeley Seismology Lab. She later competed at the International Science and Engineering Fair, established a nonprofit named Melior Earth aimed at distributing affordable early-warning devices in lower-income neighborhoods with aging, less earthquake-resistant buildings, and by 2022 had been