M 7.0; 72 km ESE of Kimbe, Papua New Guinea; (4 Aug 2010) (37km from the swarm center)
M 7.3; New Britain region, Papua New Guinea; (18 Jul 2010) (47km from the swarm center)
M 7.0; 40 km S of Kimbe, Papua New Guinea; (31 Oct 2001) (91km from the swarm center)
M 7.8; 138 km SSW of Kokopo, Papua New Guinea; (17 Nov 2000) (98km from the swarm center)
Seismic Swarm PS20061017.1: Analysis of Events Near Kimbe, Papua New Guinea
A seismic swarm designated PS20061017.1 was recorded in the region 105 km east-southeast of Kimbe, Papua New Guinea. The sequence began at 01:25 on 17 October 2006 and concluded at 02:09 on 18 October 2006, encompassing six earthquakes within a span of 24 hours and 43 minutes. The largest event reached magnitude 6.7 at a depth of 32 km, followed by five additional shocks ranging from magnitude 4.6 to 5.4 at depths between 13 km and 35 km.
The events unfolded as follows: a magnitude 6.7 earthquake at 01:25 on 17 October at 32 km depth; a magnitude 5.0 at 04:20 on 17 October at 27 km depth; another magnitude 5.0 at 06:10 on 17 October at 33 km depth; a magnitude 4.6 at 08:18 on 17 October at 13 km depth; a magnitude 5.4 at 08:58 on 17 October at 35 km depth; and a magnitude 5.3 at 02:09 on 18 October at 35 km depth. Such swarms reflect clustered seismic energy release without a dominant mainshock-aftershock pattern.
Papua New Guinea’s New Britain region, including the area near Kimbe, occupies a tectonically complex zone at the convergent boundary between the Australian and Pacific plates. Subduction along the New Britain Trench drives frequent seismicity, with intermediate-depth events common due to the downgoing slab. The region has produced multiple magnitude 7.0+ earthquakes since 2000, including a magnitude 7.0 event 119 km east of Kimbe on 10 October 2018, a magnitude 7.0 event 72 km east-southeast of Kimbe on 4 August 2010, a magnitude 7.3 event in the New Britain region on 18 July 2010, a magnitude 7.0 event 40 km south of Kimbe on 31 October 2001, and a magnitude 7.8 event 138 km south-southwest of Kokopo on 17 November 2000. These larger shocks occurred between 35 km and 98 km from the swarm centroid, underscoring persistent strain accumulation along the plate interface.
Historical records indicate four prior swarms in the vicinity since 1 January 2000, occurring in 2000 (one swarm), 2003 (one swarm), and 2005 (two swarms). This pattern illustrates episodic swarm activity superimposed on the region’s background of great subduction-zone earthquakes.
References
- SeismoSight internal swarm classification data (PS20061017.1)
- USGS Earthquake Catalog (strong events since 2000)
- Geological Survey of Papua New Guinea tectonic summaries