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New insights into the present-day kinematics of the central and western Papua New Guinea from GPS.

Koulali, Achraf; Tregoning, Paul; McClusky, Simon; Stanaway, R; Wallace, L; Lister, Gordon

Description

New Guinea is a region characterized by rapid oblique convergence between the Pacific and Australian tectonic plates. The detailed tectonics of the region, including the partitioning of relative block motions and fault slip rates within this complex boundary plate boundary zone are still not well understood. In this study, we quantify the distribution of the deformation throughout the central and western parts of Papua New Guinea (PNG) using 20 yr of GPS data (1993–2014). We use an elastic...[Show more]

dc.contributor.authorKoulali, Achraf
dc.contributor.authorTregoning, Paul
dc.contributor.authorMcClusky, Simon
dc.contributor.authorStanaway, R
dc.contributor.authorWallace, L
dc.contributor.authorLister, Gordon
dc.date.accessioned2016-06-14T23:21:41Z
dc.identifier.issn0956-540X
dc.identifier.urihttp://hdl.handle.net/1885/104031
dc.description.abstractNew Guinea is a region characterized by rapid oblique convergence between the Pacific and Australian tectonic plates. The detailed tectonics of the region, including the partitioning of relative block motions and fault slip rates within this complex boundary plate boundary zone are still not well understood. In this study, we quantify the distribution of the deformation throughout the central and western parts of Papua New Guinea (PNG) using 20 yr of GPS data (1993–2014). We use an elastic block model to invert the regional GPS velocities as well as earthquake slip vectors for the location and rotation rates of microplate Euler poles as well as fault slip parameters in the region. Convergence between the Pacific and the Australian plates is accommodated in northwestern PNG largely by the New Guinea Trench with rates exceeding 90 mm yr−1, indicating that this is the major active interplate boundary. However, some convergent deformation is partitioned into a shear component with ∼12 per cent accommodated by the Bewani-Torricelli fault zone and the southern Highlands Fold-and-Thrust Belt. New GPS velocities in the eastern New Guinea Highlands region have led to the identification of the New Guinea Highlands and the Papuan Peninsula being distinctly different blocks, separated by a boundary through the Aure Fold-and-Thrust Belt complex which accommodates an estimated 4–5 mm yr−1 of left-lateral and 2–3 mm yr−1 of convergent motion. This implies that the Highlands Block is rotating in a clockwise direction relative to the rigid Australian Plate, consistent with the observed transition to left-lateral strike-slip regime observed in western New Guinea Highlands. We find a better fit of our block model to the observed velocities when assigning the current active boundary between the Papuan Peninsula and the South Bismark Block to be to the north of the city of Lae on the Gain Thrust, rather than on the more southerly Ramu-Markham fault as previously thought. This may indicate a temporary shift of activity onto out of sequence thrusts like the Gain Thrust as opposed to the main frontal thrust (the Ramu-Markham fault). In addition, we show that the southern Highlands Fold-and-Thrust Belt is the major boundary between the rigid Australian Plate and the New Guinea Highlands Block, with convergence occurring at rates between ∼6 and 13 mm yr−1.
dc.publisherOxford University Press
dc.rightsAuthor/s retain copyright
dc.sourceGeophysical Journal International
dc.titleNew insights into the present-day kinematics of the central and western Papua New Guinea from GPS.
dc.typeJournal article
local.description.notesImported from ARIES
local.identifier.citationvolume202
dc.date.issued2015
local.identifier.absfor040402 - Geodynamics
local.identifier.absfor040313 - Tectonics
local.identifier.ariespublicationu8906087xPUB41
local.type.statusPublished Version
local.contributor.affiliationKoulali, Achraf, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationTregoning, Paul, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationMcClusky, Simon, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationStanaway, R , School of Civil & Environ Engineering
local.contributor.affiliationWallace, L, The University of Texas at Austin
local.contributor.affiliationLister, Gordon, College of Physical and Mathematical Sciences, ANU
local.bibliographicCitation.startpage993
local.bibliographicCitation.lastpage1004
local.identifier.doi10.1093/gji/ggv200
local.identifier.absseo970104 - Expanding Knowledge in the Earth Sciences
dc.date.updated2016-06-14T09:18:35Z
dcterms.accessRightsOpen Access
CollectionsANU Research Publications

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