Frequency of Earthquakes Worldwide The following table lists the frequency of earthquakes worldwide, according to magnitude and annual average. DescriptorMagnitudeAnnual average Great8 or higher11 Major7–7.9172 Strong6–6.91342 Moderate5–5.91,3192 Light4–4.9c. 13,000 Minor3–3.9c. 130,000 Very minor2–2.9c. 1,300,000 1. Based on observations since 1900. 2. Based on observations since 1990. NOTE: The NEIC estimates that several million earthquakes occur in the world each year. Many go undetected because they hit remote areas or have very small magnitudes. Source:National Earthquake Information Center, U.S. Geological Survey.