PlainQuake

About PlainQuake

Our Mission

PlainQuake exists because we believe earthquake data should be accessible to everyone, not just seismologists with specialized software. The U.S. Geological Survey maintains one of the most comprehensive earthquake catalogs in the world, but navigating their raw data feeds and query interfaces can be daunting for non-specialists.

We built PlainQuake to bridge that gap. Our mission is to transform raw seismological data into an intuitive, searchable resource that helps researchers, educators, journalists, emergency managers, and curious individuals understand earthquake patterns across the globe. Whether you are studying seismic risk for a school project, investigating earthquake frequency for a news article, or comparing historical seismicity between regions, PlainQuake gives you the answers in seconds.

We believe that public safety data belongs in the hands of the public. By making earthquake records browsable by year, country, and U.S. state, we help more people understand the seismic forces that shape our world.

Our Data Sources

All earthquake data on PlainQuake comes from the U.S. Geological Survey (USGS) Earthquake Hazards Program, the official source for global seismic monitoring. We draw from two primary datasets:

  • Global M4+ Catalog (2005 – present): Every earthquake of magnitude 4.0 and above recorded worldwide by the USGS global seismographic network. This catalog contains over 300,000 events and is accessed via the USGS ComCat FDSN Event Web Service API.
  • Significant Earthquake Catalog (1900 – present): Major earthquakes of magnitude 6.0 and above, with historical records spanning over a century. Approximately 14,000 events capturing the most consequential seismic activity in modern history.

No data on PlainQuake is fabricated, estimated, or interpolated. Every event record, magnitude, depth, location, and timestamp, comes directly from the USGS catalog without modification.

How We Process the Data

Our methodology begins with querying the USGS ComCat earthquake catalog API to download every recorded M4+ event globally and M6+ significant events historically. The raw catalog data arrives as CSV files containing event parameters including magnitude, depth, latitude, longitude, timestamp, and place description.

Each earthquake record is geocoded to a country using the USGS-provided place description, and U.S. events are further mapped to their respective state. We then compute aggregate statistics at multiple geographic levels: annual earthquake counts and magnitude distributions by year, country-level seismic profiles with total counts, significant events, and maximum recorded magnitudes, and state-level seismic summaries for the 38 U.S. states and territories with recorded M4+ activity.

Our approach is strictly descriptive. We compute counts, averages, maximums, and distributions from the raw USGS records. We do not apply predictive models, generate forecasts, or make inferences about future seismic activity. The data is what the instruments recorded, nothing more, nothing less.

Data Currency

PlainQuake's database is refreshed when new data becomes available from the USGS. The USGS continuously updates its earthquake catalog as events are detected and reviewed by seismologists. Our update schedule follows USGS publication cycles, typically quarterly for comprehensive catalog updates, with significant events appearing in near-real-time on the USGS site.

The global M4+ catalog currently covers events from 2005 through 2025. The significant earthquake catalog extends back to 1900, with the most complete coverage from the 1960s onward when the global seismographic network achieved broad geographic reach. Historical data prior to 1960 relies on fewer stations and carries larger magnitude uncertainties. Data freshness is noted on individual pages where applicable.

Editorial Independence

The country, state, year, and magnitude profiles on PlainQuake are generated automatically by our data pipeline directly from the USGS ComCat earthquake catalog, the figures are computed by script and rendered server-side, not hand-curated. PlainQuake, is responsible for the data framing, methodology, and corrections process described on our methodology page.

We do not accept payment, sponsorship, or promoted placement from government agencies, seismological organizations, or any covered entity. Our only revenue source is contextual display advertising served by Google AdSense, advertisers do not influence which entities we cover or how we present data, and they do not receive preferential placement.

Limitations and Disclaimers

  • Detection coverage varies by region. The USGS seismographic network provides excellent coverage in North America, Japan, and Europe, but remote oceanic regions, central Africa, and parts of central Asia may have incomplete records for smaller earthquakes.
  • Historical magnitude uncertainties. Pre-1960 earthquake magnitudes are estimated from historical intensity reports and early instrumental records. These estimates carry larger uncertainties than modern instrumental measurements.
  • Country attribution is approximate. Geographic assignment is based on the USGS place description field and reverse geocoding. Earthquakes near national borders or in disputed territories may not perfectly match political boundaries.
  • Not a warning system. PlainQuake is a historical data reference tool. Do not use this site as a substitute for official earthquake early warning systems, tsunami alerts, or emergency notifications from FEMA, USGS ShakeAlert, or your local emergency management agency.
  • No predictive capability. Earthquake occurrence cannot be reliably predicted. Nothing on this site should be interpreted as a forecast of future seismic activity in any region.

PlainQuake is not affiliated with, endorsed by, or connected to the U.S. Geological Survey or any government agency. This site is for informational and educational purposes only. Data is provided "as is" without warranty of any kind.

Contact

Questions, feedback, or data corrections? Reach out at hello@plainquake.com. We welcome reports of data discrepancies and suggestions for improving the site.