Reading a major earthquake report from first alert to revision
Early notices can be useful without being final. Additional seismic stations may lead agencies to refine an event’s magnitude, depth, coordinates and mechanism.
Review earthquake terms →Daily important quakes
Major earthquake reports
A focused archive for stronger or otherwise significant seismic events. Reports organize location, magnitude, depth and available impact context while recognizing that initial agency estimates may change.
Open overview map
Archive desk
Recent editorial reviews
These archive guides explain how significant events are assessed. Dates show editorial review rather than the time of a specific earthquake.
Why depth changes the shaking picture
Shallow events can produce intense nearby shaking, but observed effects also depend on geology, rupture behavior and construction.
Read in-depth reports →
When strong coastal shaking needs immediate action
People near a coast should follow local evacuation guidance after long or strong shaking and avoid waiting near the shoreline.
Review tsunami preparedness →
Magnitude alone does not describe damage
Distance, local soils, landslides, building vulnerability and population exposure all influence consequences.
Browse magnitude 6+ archive →
What fault-motion diagrams can tell us
Focal-mechanism diagrams summarize possible fault orientation and movement but do not depict the physical shape of the event.
Understand the diagrams →Important: This archive is informational. For active warnings, evacuation orders and local impact assessments, use the responsible seismic and emergency-management authorities in the affected area.
Reading the data
What makes an event significant?
Magnitude is a useful starting point, not a complete measure of risk or impact.
Core report fields
- Origin time and locationCoordinates and place descriptions establish where and when an agency located the event.
- MagnitudeA logarithmic estimate of earthquake size that may be revised as more observations become available.
- DepthThe estimated distance below the surface, with uncertainty that can be substantial in early solutions.
- Observed intensityA description of shaking effects at particular places rather than a second measure of magnitude.
Browse established indexes
How we work
Building a responsible event summary
Earthquake Report separates verified seismic parameters from uncertain or developing impact information.
Check the signal
Compare available agency estimates for time, location, depth and magnitude.
Mark revisions
Treat early parameters as preliminary and recognize that different methods can produce different values.
Add context
Describe nearby communities, coastlines and tectonic setting without inferring damage from size alone.
Prioritize safety
Keep preparedness visible while deferring urgent instructions to responsible local authorities.
Common questions
Major earthquake FAQ
Why can two agencies report different magnitudes?
Agencies may use different station networks, seismic-wave measurements and magnitude methods. Values often converge as analyses are refined.
Does a high magnitude guarantee severe damage?
No. Damage depends on depth, distance, rupture direction, local ground, building vulnerability and exposure as well as magnitude.
Why does an earthquake location move after the first report?
Initial locations rely on limited station arrivals. More data and improved models can change the estimated epicenter and depth.
Are aftershocks always smaller?
Most are smaller than the main event, but additional strong shaking remains possible. Follow local safety guidance and avoid damaged structures.
Can earthquakes be predicted exactly?
No reliable method identifies the exact date, location and magnitude of a future tectonic earthquake. Probability forecasts are not predictions.
What should I do during shaking?
Follow local authority guidance. Indoors, commonly recommended action is to drop, cover and hold on while staying away from windows.
About this archive
Careful context for significant seismic events
Earthquake Report organizes major earthquake information for readers who need a clear route from an initial event notice to deeper seismic context. The archive is not an emergency alert service and should not replace official national or local bulletins.
Editorial questions and corrections can be sent to info@earthquakereport.com-html.com.
Learn more about Earthquake Report →