Location:

Period:

22 Mar 2014 12:59:59 - 23 Mar 2014 18:20:01 (1 day 5 hours 20 minutes)

Volcanoes in 100km radius:

None

Earthquakes:

M 7.0+:

M 8.2; 93 km NW of Iquique, Chile; (1 Apr 2014) (18km from the swarm center)

7 swarms found nearby.

2014

PS20140317.1(32.3km)

16 Mar

11 hours

9 earthquakes

S20140317.1(8.4km)

16 Mar

12 days 5 hours

196 earthquakes

S20140323.1(11.4km)

22 Mar

1 day 22 hours

41 earthquakes

S20140324.1(20.0km)

23 Mar

3 days 15 hours

80 earthquakes

PS20140401.1(70.1km)

1 Apr

2 days 9 hours

43 earthquakes

S20140402.1(19.8km)

2 Apr

8 days 9 hours

88 earthquakes

S20140404.1(95.1km)

3 Apr

6 days 23 hours

68 earthquakes

AI-generated article — for informational and entertainment purposes only. May contain inaccuracies. Full disclaimerFound an error?

Seismic Swarm Activity Near Iquique, Chile, March 2014

The region offshore northern Chile, approximately 103 km west-northwest of Iquique, lies within the Peru-Chile subduction zone where the Nazca Plate descends beneath the South American Plate. This tectonic setting produces frequent seismic events at depths typically ranging from 10 to 30 km, consistent with interplate and intraslab faulting. The area has long been recognized for elevated seismic hazard due to the convergence rate of about 6–7 cm per year.

SeismoSight internal records document swarm PS20140322.1 as commencing at 12:59 on 22 March 2014 and concluding at 18:20 on 23 March 2014. Over this 29-hour-20-minute interval, six earthquakes were registered. The sequence included the following events:

22 March 2014 12:59:59, magnitude 6.2, depth 20 km
22 March 2014 13:14:58, magnitude 5.2, depth 24 km
22 March 2014 13:29:58, magnitude 5.6, depth 17 km
22 March 2014 22:14:58, magnitude 5.0, depth 21 km
22 March 2014 22:51:16, magnitude 4.0, depth 19 km
23 March 2014 18:20:01, magnitude 6.3, depth 21 km

Historical statistics maintained since 1 January 2000 indicate that only two swarms have been identified in the broader region, with this March 2014 sequence representing the first recorded instance. Ten days later, on 1 April 2014, a magnitude 8.2 earthquake occurred 93 km northwest of Iquique, approximately 18 km from the swarm centroid. This mainshock remains one of the strongest events in the instrumental record for the area and was followed by an extensive aftershock sequence.

The March swarm exhibited a compact spatial footprint and rapid succession of moderate-magnitude events at similar focal depths, features commonly observed in subduction-zone preparatory sequences. Depths between 17 km and 24 km align with the expected range for megathrust interface activity in this segment of the plate boundary. No surface rupture or significant tsunami was associated with the swarm itself.

Long-term monitoring of the Iquique segment underscores its capacity for great earthquakes, with paleoseismic evidence pointing to prior events in the nineteenth century. Modern instrumentation has improved detection of precursory swarms, aiding in the characterization of stress accumulation along the locked portion of the subduction interface.

References
USGS Earthquake Catalog
SeismoSight internal swarm classification records