The magnitude 5.0 jolt struck at 11:32 a.m. local time about 6 miles southwest of downtown Christchurch. The strong shaking sent residents rushing out of buildings across the city.
Businesses and schools were evacuated, including the international airport. Engineers later cleared the runways for takeoffs and landings after checking for cracks.
The aftershock was the most violent shaking the Canterbury region has experienced since a 7.1 magnitude quake on September 4 damaged about 50,000 homes and left 1,200 of them so wrecked that they will need to be rebuilt.
Officials estimate the full damage for the quake could reach nearly $3 billion.
Tuesday’s seismic reminder sent items flying off shelves and damaged water mains in one neighborhood, leaving residents there without water supplies.
Scientists at the country’s GeoNet earthquake agency said that aftershocks can last for months or even years following an initial earthquake as strong as that of September 4.