The Cahuilla earthquake swarm produced earthquakes from early 2016 through 2019 and caused no significant damage despite lasting four years.
Notes on verification
Multiple independent sources (Caltech, ScienceDaily, Science News, Smithsonian, Wikipedia) corroborate the timeline, magnitude range, and absence of significant damage.
Sources
- A strange earthquake swarm lasted for years. Scientists finally know ... (nationalgeographic.com)
- https://www.sciencenews.org/article/machine-learning-california-earthquake-swarm (sciencenews.org)
- https://www.caltech.edu/about/news/natural-fluid-injections-triggered-cahuilla-earthquake-swarm (caltech.edu)
- https://www.smithsonianmag.com/smart-news/earthquake-swarm-reveals-complex-structure-california-fault-line-180975161/ (smithsonianmag.com)