Earthquakes Near Mammoth Lakes Today
Live answer from USGS data — every earthquake within 150 km (93 mi) of Mammoth Lakes, California.
Checking live USGS data near Mammoth Lakes…
Why Mammoth Lakes gets earthquakes
Mammoth Lakes sits inside the Long Valley Caldera, a 20-mile-wide volcanic depression formed by a colossal eruption 760,000 years ago. In May 1980, four M6 earthquakes struck in just two days, beginning decades of unrest that included swarms, ground uplift, and tree-killing CO2 emissions at Horseshoe Lake.
Earthquakes here are a mix of tectonic (Sierra Nevada frontal faults like the Hilton Creek fault) and volcanic-hydrothermal activity under the caldera. Swarms of dozens to hundreds of small quakes are normal and closely monitored by the USGS California Volcano Observatory.
Mammoth Lakes earthquake FAQ
▸Did Mammoth Lakes just have an earthquake?
The live panel at the top of this page checks the USGS catalog for every earthquake within 150 km of Mammoth Lakes and answers in one line. Keep in mind USGS data lags real shaking by roughly 2–3 minutes in California and up to ~8 minutes in other regions — if you felt something seconds ago, refresh shortly.
▸What faults cause earthquakes near Mammoth Lakes?
Mammoth Lakes sits in the Long Valley Caldera, where volcanic and hydrothermal activity produces frequent earthquake swarms. The Hilton Creek fault and other Sierra Nevada frontal faults add tectonic sources — four M6 quakes struck in two days in May 1980.
▸What magnitude earthquake can you feel in Mammoth Lakes, CA?
Close to the epicenter, people typically begin to feel earthquakes around magnitude 2.5–3.0. An M4+ is felt across a wide area and rattles objects; M5+ can damage buildings near the epicenter. Shallow quakes feel stronger than deep ones of the same magnitude, and soft soils amplify shaking.
▸What should I do if I feel an earthquake in Mammoth Lakes?
Drop, Cover, and Hold On — get low, take cover under sturdy furniture, and hold on until shaking stops. Afterward, check for hazards like gas leaks, and expect possible aftershocks. If you're in a coastal area and the shaking is strong or lasts a long time, move inland or to high ground. Official guidance: ready.gov/earthquakes.