The Cahuilla earthquake swarm began in 2016 but went unnoticed until 2017, when a citizen emailed the Southern California Seismic Network about a cluster of tiny earthquakes.
Notes on verification
Confirmed by National Geographic's original reporting and independently corroborated by Smithsonian Magazine, Science News, and a National Academies article quoting the lead researcher directly. [tier=unverified indep_score=0.3 clusters=3 claim_tier=notable] [rescored 2026-09-15: curated origin-host map (PR #65); unclassified hosts no longer scored as aggregators]
Sources
- A strange earthquake swarm lasted for years. Scientists finally know ... (seed:environment_and_wildlife)
- https://www.sciencenews.org/article/machine-learning-california-earthquake-swarm (corroboration)
- https://www.smithsonianmag.com/smart-news/earthquake-swarm-reveals-complex-structure-california-fault-line-180975161/ (corroboration)
- https://www.nationalacademies.org/news/how-science-is-using-ai-to-translate-the-nonstop-chatter-of-the-earth (corroboration)