Location:

Period:

19 Apr 2001 02:40:36 - 20 Apr 2001 19:20:50 (1 day 16 hours 40 minutes)

Volcanoes in 100km radius:

None

Earthquakes:

11 swarms found nearby.

2001

PS20010530.1(96.0km)

29 May

5 hours

5 earthquakes

2007

PS20070217.1(26.2km)

17 Feb

4 hours

7 earthquakes

PS20070401.2(156.3km)

1 Apr

2 days 12 hours

62 earthquakes

PS20070404.1(39.0km)

4 Apr

10 hours

5 earthquakes

2014

PS20140411.1(114.1km)

11 Apr

2 days 6 hours

19 earthquakes

PS20140419.1(162.3km)

19 Apr

2 days 20 hours

28 earthquakes

PS20140507.1(121.3km)

6 May

22 hours

5 earthquakes

PS20141207.1(191.2km)

7 Dec

1 day 11 hours

11 earthquakes

2015

PS20150507.1(130.6km)

7 May

19 hours

10 earthquakes

2017

PS20170304.1(25.5km)

4 Mar

51 minutes

5 earthquakes

2020

PS20201229.1(177.7km)

28 Dec

6 hours

5 earthquakes

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Seismic Swarm PS20010419.1: Analysis of Earthquake Activity Near Panguna, Papua New Guinea

A seismic swarm designated PS20010419.1 occurred in the region 128 km south-southeast of Panguna on Bougainville Island, Papua New Guinea. The sequence began at 02:40 on 19 April 2001 and concluded at 19:20 on 20 April 2001, spanning 40 hours and 40 minutes. During this period, seven earthquakes were recorded, with magnitudes ranging from 5.0 to 6.7 and focal depths between 10 and 20 km.

The events unfolded as follows. The initial shock at 02:40 on 19 April measured magnitude 5.9 at 10 km depth. Roughly 33 minutes later, a magnitude 6.0 event struck at 12 km depth. Activity resumed that evening with a magnitude 5.4 quake at 20:04, followed by a magnitude 6.2 event at 20:58 (20 km depth). The largest shock, magnitude 6.7, occurred at 21:43 at 17 km depth. A smaller magnitude 5.0 event followed at 21:56 (10 km depth). The final recorded earthquake, magnitude 5.6 at 10 km depth, took place at 19:20 on 20 April.

This swarm reflects typical tectonic behavior in Papua New Guinea, which occupies a complex plate boundary zone where the Pacific Plate subducts beneath the Australian Plate along the New Britain Trench and related structures. Bougainville Island lies within the Bismarck Volcanic Arc, an area characterized by frequent moderate-to-large earthquakes driven by oblique convergence and slab rollback. Depths of 10–20 km align with upper-crustal faulting common in this setting.

Historically, the broader Papua New Guinea region has hosted numerous earthquake sequences, including destructive events in 1998 near Aitape and 2016 near Tinputz on Bougainville. Such swarms often indicate episodic stress release along thrust or strike-slip faults without a single dominant mainshock-aftershock pattern. The 2001 sequence, with its clustered timing and moderate magnitudes, is consistent with fluid migration or aseismic slip triggering successive ruptures in the forearc region.

No surface rupture or significant tsunami was associated with this swarm, and the shallow depths suggest limited potential for widespread damage at the recorded distances from population centers. Ongoing monitoring by regional seismic networks continues to track similar activity, underscoring the persistent seismic hazard along Papua New Guinea’s eastern arc.

References

USGS Earthquake Catalog
Global CMT Project
PNG Geological Survey Tectonic Summaries