M 5.5 - Fiji region
Seismic Telemetry Specifications
5.5MWW
Moderate Seismic Class
575.9km
Deep Mantle
20.751° S, 178.584° W
GPS Coordinates
2.7 kt
TNT Equivalent Power
US
USGS Real-time Feed
Epicenter Location & Tectonic Fault Map
Is This Earthquake Dangerous?
A magnitude 5.5 event is classified as a moderate earthquake. Can cause slight to moderate damage to poorly constructed buildings. Felt widely across nearby communities within dozens of kilometers.
Estimated Shaking Radius
~100–250 km
Potential Damage Zone
~30–50 km
Focal Depth Effect
Deep Damping
What Does Magnitude 5.5 Mean?
Earthquake strength is measured on a logarithmic scale. Compare this event with the full seismic scale:
Logarithmic Energy Multiplier
Because seismic scales are logarithmic, each whole integer increase represents:
10× Ground Motion Amplitude
The seismograph wave amplitude jumps by tenfold for every 1.0 magnitude step.
~31.6× Radiated Kinetic Energy
Total energy release increases exponentially (101.5 ≈ 31.62 times per magnitude unit).
Why Did This Earthquake Happen?
Earthquakes occur when elastic stress built up along tectonic plate boundaries, regional fault lines, or crustal fractures suddenly exceeds the friction holding the rock masses together. When the fault slips, accumulated energy radiates outward in all directions as high-velocity seismic waves.
Originating at a depth of 575.9 km (Deep Mantle Transition Zone (>300 km)), this rupture occurred generated deep within earth's mantle under immense hydrostatic pressure. surface shaking is significantly damped despite large energy release.
Earthquake Safety Action Plan
- •Drop, Cover, and Hold On: Take cover beneath a sturdy table or desk.
- •Stay indoors away from exterior glass windows and heavy unanchored fixtures.
- •If outdoors, move into an open area away from power lines and building facades.
- •Inspect utilities for damaged gas lines, water leaks, or electrical hazards.
- •Expect Aftershocks: Secondary tremors frequently strike after moderate and strong events.
- •Avoid damaged structures and listen to official emergency broadcasts.
- •Maintain a 72-hour emergency go-bag with water, non-perishable food, and first aid.
- •Anchor heavy furniture, water heaters, and appliances to structural wall studs.
- •Establish a family emergency communication protocol and meeting point.
Did You Feel This Earthquake?
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