US navy tests aircraft carrier with 'full ship shock trial' explosion that registers as 3.9 magnitude earthquake

The shock trial involved the detonation of just less than 20 tonnes of explosives within metres of the ship sailing off the United States east coast.

The USS Gerald R Ford is 333 metres long, 77m high and has a displacement of 100,000 tonnes.

The United States Geological Survey recorded the explosion as a 3.9 magnitude earthquake about 161 kilometres off the coast of Florida on Friday local time. 

The navy said the schedule for the tests "complies with environmental mitigation requirements, respecting known migration patterns of marine life in the test area".

"The US navy conducts shock trials of new ship designs using live explosives to confirm that our warships can continue to meet demanding mission requirements under harsh conditions they might encounter in battle," the navy said in a statement.

"The first-in-class aircraft carrier was designed using advanced computer modelling methods, testing, and analysis to ensure the ship is hardened to withstand battle conditions, and these shock trials provide data used in validating the shock hardness of the ship."

Upon completion of the explosive tests, the ship will enter a "planned incremental availability for six months of modernisation, maintenance, and repairs" before being deployed for operations.