The April 1st, 8.2 earthquake came as a result of thrust faulting at a shallow depth of 20km near the Chilean coast. The intensity of the earthquake was such, that it was even felt as a 4.5 magnitude event in the Bolivian capital, located 470 kilometers away. Eight major aftershocks have been recorded, including a 6.2 temblor. Seismologist at the University of Chile, Mario Pardo says "More aftershocks and even a larger quake could not be ruled out". But April 1st tremor did not came as a surprise. In the last weeks, USGS has been recording a significant increase in the seismic activity in the area. On March 16, 2014 a M6.7 earthquake occurred, having a very similar faulting mechanism with the 8.2 quake, and was followed by over 60 shakings of M4+ and 26 events of M5+. Also, three significant shakings of M6.2 were recorded on March 17, March 22, and March 23.
Major damages have not yet been reported, while five people have been reported dead. The nearby cities of Iquique, Tarapaca, Arica, and Antofagasta were ordered to be evacuated, but landslides blocking the road network, caused traffic jams among residents evacuating the coast. Also, many copper mines located in the area of Iquique have not so far reported damages. Tsunami alerts were issued right after the earthquake and waves of about 2meters were observed 4 minutes after the event in the coastal area of northern Chile as well as in the town of Boca del Rio in Peru.
Sources: BBC, EpochTimes, USGS