M4+Index entry
Latest magnitude 4 and higher event index
Recent moderate events are organized for rapid review. Confirm exact origin time, coordinates, depth and magnitude with the reporting seismic agency.
Magnitude archive
Magnitude 4+ earthquakes
A focused archive for moderate seismic events worldwide, with clear reminders that magnitude alone does not determine shaking, damage or local risk.
Archive note: Event values can be revised as seismic agencies receive and analyze more station data. Use official local sources for urgent information.
Archive overview
Recent magnitude-band entries
This index presents representative archive summaries reviewed during the last 18 months. Locations and values on a live seismic feed may change after agency analysis.
M4+Context
Why a moderate shallow earthquake may be widely noticed
Shallow depth and proximity to communities can make an event more noticeable, while local soil and building conditions influence reported intensity.
M4+Offshore
Reading an offshore magnitude 4 report
An offshore location does not by itself establish tsunami danger. Follow official warning centers and local emergency guidance rather than drawing conclusions from magnitude alone.
M4+Aftershock
Moderate events within an earthquake sequence
Aftershocks can continue as a fault zone adjusts. Their frequency generally declines, but individual events remain possible and early classifications may be revised.
M4+Regional
Separating instrument magnitude from observed intensity
Magnitude measures the earthquake at its source. Intensity describes effects at a particular place, so reports can vary considerably across the affected region.
M4+Archive
Why earthquake locations and depths are updated
Initial solutions rely on the first available signals. Additional stations and analyst review can improve the estimated hypocenter and alter the published values.
M4+Research
Moderate earthquakes occur in many fault environments
Magnitude 4 events can occur near plate boundaries or within plates. Each report needs geographic and tectonic context before broader meaning is assigned.
M4+Review
Using historical lists without treating them as forecasts
Past earthquake records help describe regional seismicity, but they do not identify the exact date, location and magnitude of a future event.
How to read the data
Three values need context
Early earthquake summaries are useful, but no single field provides a complete account of what happened on the ground.
Magnitude
A logarithmic measurement of earthquake size. A small numerical change represents a substantial change in released energy.
Depth
The estimated distance below the surface. Shallow events can produce stronger nearby shaking, though other factors remain important.
Intensity
A description of observed shaking and effects at a location. It varies with distance, ground conditions and the built environment.
How we work
From preliminary event to archive context
Earthquake Report treats the first automatic solution as a starting point rather than a final conclusion.
- Check the basic solution. Review agency time, coordinates, magnitude and depth.
- Place it geographically. Note nearby communities, coastlines and the broad tectonic setting.
- Label uncertainty. Avoid turning preliminary values or unverified reports into confirmed impacts.
- Keep safety sources visible. Direct urgent decisions to local civil-protection and emergency authorities.
Common questions
Magnitude 4 archive FAQ
Is a magnitude 4 earthquake dangerous?
Impact cannot be determined from magnitude alone. Depth, distance, local geology, building vulnerability and secondary hazards all affect consequences.
Why are some magnitude 4 events not felt?
An event may be deep, remote or offshore. Human perception also varies with ground conditions, distance, building height and ambient activity.
Why can a magnitude change after publication?
Automatic estimates use limited early data. Agencies refine the solution as more seismic stations and analyst reviews become available.
Can a magnitude 4 event cause a tsunami?
Magnitude alone is not enough to assess tsunami risk. Use official tsunami-warning centers and local evacuation instructions after strong or long coastal shaking.
Is every later event an aftershock?
No. Seismologists consider timing, location and the relationship to the earlier rupture. Event labels may change as a sequence is analyzed.
Does a cluster mean a larger earthquake is imminent?
A cluster does not provide an exact prediction. Seismicity is monitored probabilistically, and no reliable method specifies a future event’s precise time, place and magnitude.
About this archive
A focused route through moderate events
The magnitude 4+ category helps readers find moderate earthquake entries without implying that every event has the same effect. Earthquake Report combines archive organization with plain-language explanations of preliminary seismic data.
For corrections, accessibility feedback or archive questions, email info@earthquakereport.com-html.com.
Learn more about Earthquake Report →