Light 4.5 Earthquake – Alaska Peninsula
A light magnitude 4.5 earthquake struck near Alaska Peninsula on Tuesday, March 28, 2017 at 08:59:58 PM UTC. This shallow crustal event (45.6 km depth) released energy equivalent to approximately 85 tons of TNT. Here is the verified AK telemetry, live epicenter map, and ground shaking assessment.
Seismic Telemetry Specifications
4.5MW
Light Seismic Class
45.6km
Crustal Layer
56.312° N, 156.240° W
GPS Coordinates
85 tons
TNT Equivalent Power
AK
USGS Real-time Feed
Epicenter Location & Tectonic Fault Map
Is This Earthquake Dangerous?
A magnitude 4.5 event is classified as a light earthquake. Noticeable shaking of indoor objects and rattling doors/windows. Generally causes none to slight non-structural damage in older buildings.
Estimated Shaking Across Nearby Communities
The epicenter occurred in a remote or offshore marine sector with no major population centers situated within the primary ground shaking perimeter.
Did You Feel This Earthquake?
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Your immediate response verifies shaking boundaries and helps ground-truth instrumental models.
What Does Magnitude 4.5 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:
Why Did This Earthquake Happen?
The western North American margin is shaped by the Pacific Ring of Fire, including the 800-mile San Andreas transform fault system and the Cascadia Subduction Zone. Lateral strike-slip motion between the Pacific and North American plates drives continuous crustal deformation across the region.
Originating at a depth of 45.6 km (Earth's Crust (0–70 km)), this rupture occurred occurred within the brittle upper crust. shallow earthquakes produce the highest peak ground acceleration and the sharpest surface shaking.
Aftershock Outlook & Secondary Tremors
Seismologists note that minor aftershocks remain common in the 24 to 48 hours following tremors of magnitude 4.5. According to statistical seismic models, there is roughly a 5% probability of a subsequent event of equal or greater strength occurring in the same fault zone. Residents in United States are advised to check living spaces for unsecured items.
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Earthquake Safety Action Plan
Complete Safety Guide →- •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 significant events.
- •Avoid damaged structures and listen to official emergency broadcasts.
- •Maintain a 72-hour emergency go-bag with water, food, and first aid.
- •Anchor heavy furniture, water heaters, and appliances to structural studs.
- •Establish a family emergency communication protocol and meeting point.
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