The swarm began with a 6.2 magnitude temblor that prompted more than 100,000 coastal residents to briefly evacuate low-lying areas.
More than a dozen quakes were felt in the port of Iquique on Monday alone.
The epicenters of most of the quakes were about 60 miles northwest of the copper-exporting city.
“The situation is out of the ordinary. There’s a mix of a string of tremors and their aftershocks that make things more complex to evaluate,” Mario Pardo, deputy head of the University of Chile’s seismology center, told the daily La Tercera. “We can't rule out a larger quake.”
Chile has suffered from many powerful temblors during its recorded history, including the strongest ever recorded on the planet.
A May 22, 1960, temblor on the central coast registered a magnitude of 9.5 and killed approximately 1,655 from its strong shaking and massive tsunami.