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<meta content="Reading, A.M." name="eprints.creators_name" />
<meta content="Gubbins, D." name="eprints.creators_name" />
<meta content="Mao, W." name="eprints.creators_name" />
<meta content="Anya.Reading@utas.edu.au" name="eprints.creators_id" />
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<meta content="A multiphase seismic investigation of the shallow subduction zone, southern North Island, New Zealand" name="eprints.title" />
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<meta content="converted phase, Hikurangi margin, New Zealand, plate topography, subduction zone." name="eprints.keywords" />
<meta content="The shallow structure of the Hikurangi margin, in particular the interface between the Australian Plate and the subducting Pacific Plate, is investigated using the traveltimes of direct and converted seismic phases from local earthquakes. Mode conversions take place as upgoing energy from earthquakes in the subducted slab crosses the plate interface. These PS and SP converted arrivals are observed as intermediate phases between the direct P and S waves. They place an additional constraint on the depth of
the interface and enable the topography of the subducted plate to be mapped across the region.
301 suitable earthquakes were recorded by the Leeds (Tararua) broad-band seismic array, a temporary line of three-component short-period stations, and the permanent
stations of the New Zealand national network. This provided coverage across the land area of southern North Island, New Zealand, at a total of 17 stations. Rays are traced
through a structure parametrized using layered B-splines and the traveltime residuals inverted, simultaneously, for hypocentre relocation, interface depth and seismic velocity.
The results are consistent with sediment in the northeast of the study region and gentle topography on the subducting plate. This study and recent tectonic reconstructions of
the southwest Pacific suggest that the subducting plate consists of captured, oceanic crust. The anomalous nature of this crust partly accounts for the unusual features of the Hikurangi margin, e.g. the shallow trench, in comparison with the subducting margin further north." name="eprints.abstract" />
<meta content="2001-09" name="eprints.date" />
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<meta content="Geophysical Journal International" name="eprints.publication" />
<meta content="147" name="eprints.volume" />
<meta content="1" name="eprints.number" />
<meta content="215-226" name="eprints.pagerange" />
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<meta content="0956-540X" name="eprints.issn" />
<meta content="Aki, K. & Richards, P., 1980. Quantitative Seismology: Theory and Methods, Vol. 1, W.H. Freeman, San Francisco, CA.
Ansell, J. & Bannister, S., 1996. Shallow morphology of the subducted Pacific plate along the Hikurangi margin, New Zealand, Phys. Earth planet. Inter., 93, 3-20.
Ansell, J. & Smith, E., 1975. Detailed structure of a mantle seismic zone using the homogeneous station method, Nature, 253, 518-520.
Bannister, S., 1988. Microseismicity and velocity structure in the Hawkes Bay region New Zealand: fine structure of the subducting Pacific plate, Geophys. J., 95, 45-62.
Barnes, P. & de Lepinay, B.M., 1997. Rates and mechanics of rapid frontal accretion along the very obliquely convergent southern HikurangiMargin, New Zealand, J. geophys. Res., 102, 24 931-24 952.
Barnes, P., de Lepinay, B.M. & Jean-Yves Collot, J.D., 1998. Strain partitioning in the transition area between oblique subduction and continental collision, Hikurangi Margin, New Zealand, Tectonics, 17, 534-557.
Bradshaw, J.D., 1989. Cretaceous geotectonic patterns in the New Zealand region, Tectonics, 8, 803-820.
Bray, T., 1991. The determination of the velocity structure in the upper mantle by seismic traveltime inversion, PhD thesis, University of Cambridge, Cambridge.
Brisbourne, A., Stuart, G. & Kendall, J., 1999. Anisotropic structure of the Hikurangi subduction zone, New Zealand-integrated interpretation of surface-wave and body-wave data, Geophys. J. Int., 137, 214-230.
Chadwick, M., 1996. Structure along the shallow part of a subduction zone: Palliser Bay to Hawkes Bay refraction experiment, New Zealand, PhD thesis, Victoria University, Wellington.
Chanier, F., Ferriere, J. & Angelier, J., 1999. Extensional deformation across an active margin, relations with subsidence, uplift and rotations: The Hikurangi subduction, New Zealand, Tectonics, 18, 862-876.
Davy, B. & Wood, R., 1994. Gravity and magnetic modelling of the Hikurangi Plateau, Mar. Geol., 118, 139-151.
de Boor, C., 1972. On calculating with B-splines, J. Approx. Theory, 6,50-62.
Eberhart-Phillips, D. & Reyners, M., 1997. Continental subduction and three-dimensional crustal structure: the northern South Island, New Zealand, J. geophys. Res., 102, 11 843-11 861.
Eberhart-Phillips, D. & Reyners, M., 1999. Plate interface properties in the northeast Hikurangi subduction zone, New Zealand, from converted seismic waves, Geophys. Res. Lett., 26, 2565-2568.
Franklin, J., 1970. Well-posed stochastic extensions of ill-posed linear problems, J. math. Anal. Appl., 31, 682-716.
Gledhill, K. & Stuart, G., 1996. Seismic anisotropy in the fore-arc region of the Hikurangi subduction zone, New Zealand, Phys. Earth planet. Inter., 95, 211-225.
Gubbins, D., Barnicoat, A. & Cann, J., 1994. Seismological constraints on the gabbro-eclogite transition in subducted oceanic crust, Earth planet. Sci. Lett., 122, 89-101.
Helffrich, G. & Stein, S., 1993. Study of the structure of the slab-mantle interface using reflected and converted seismic waves, Geophys. J. Int., 115, 14-40.
Helffrich, G., Stein, S. & Wood, B.J., 1989. Subduction zone thermal structure and mineralogy and their relationship to seismic wave reflections and conversions at the slab/mantle interface, J. geophys. Res., 94, 753-763.
Iidaka, T., Mizoue, M., Nakamura, I., Tsukuda, T., Sakai, K.,Kobayasi, M., Haneda, T. & Hashimoto, S., 1990. The upper
boundary of the Philippine Sea plate beneath the western Kanto region estimated from S-P converted waves, Tectonics, 179, 321-326.
Lancaster, P. & Salkauskas, K., 1986. Curve and Surface Fitting: An Introduction, Academic Press, London.
Lodge, R., Steblov, G. & Gubbins, D., 1999. Fundamental leaking mode (PL) propagation along the Tonga-Kermadec-Hikurangi-Macquarie margin, Geophys. J. Int., 137, 675-690.
Luyendyk, B., 1995. Hypothesis for Cretaceous rifting of East Gondwana caused by subducted slab capture, Geology, 23,
373-376.
Mao, W. & Stuart, G., 1997. Rapid ray tracing for multi-wavetype tomography in complex 2-D and 3-D isotropic media, Geophysics,62, 298-308.
Marson-Pidgeon, K., Savage, M.K., Gledhill, K. & Stuart, G.,
1999. Seismic anisotropy beneath the lower half of North Island,New Zealand, J. geophys. Res., 104, 20 277-20 286.
Powell, M., 1991. Approximation Theory and Methods, Cambridge University Press, Cambridge.
Reading, A.M., 1996. Deep lithospheric structure from multi-phase tomography: the subduction zone beneath southern North Island,New Zealand, PhD thesis, University of Leeds, Leeds.
Reading, A.M., Mao, W. & Gubbins, D., 2001. Polarization filtering for automatic picking of seismic data and improved converted phase detection, Geophys. J. Int., 147, 227-234 (this issue).
Robinson, R., 1986. Seismicity, structure and tectonics of the Wellington region, Geophys. J. R. astr. Soc., 87, 379-409.
Samson, J.C. & Olson, J.V., 1981. Data-adaptive Polarization filters for multichannel geophysical data, Geophysics, 46, 1423-1431.
Smith, E.G.C., Stern, T. & Reyners, M., 1989. Subduction and backarc activity at the Hikurangi convergent margin, New Zealand, Pure appl. Geophys., 129, 203-231.
Smith, G., Gubbins, D. & Mao, W., 1994. Fast P-wave propagation in subducted Pacific lithosphere-refraction from the plate, J. geophys.Res., 99, 23 787-23 800.
Smith, W.D., 1970. S to P conversion as an aid to crustal studies,Geophys. J. R. astr. Soc., 19, 513-519.
Spencer, C. & Gubbins, D., 1980. Travel-time inversion for simultaneous earthquake location and velocity structure determination in laterally varying media, Geophys. J. R. astr. Soc., 63, 95-116.
Stuart, G., Francis, D., Gubbins, D. & Smith, G., 1995. Tararua broadband array, North Island, New Zealand, Bull. seism. Soc. Am., 85, 325-333.
Walcott, R., 1987. Geodetic strain and the deformational history of the North Island of New Zealand during the late Cainozoic, Phil. Trans.R. Soc. Lond., 321, 231-277.
Wessel, P. & Kroenke, L.W., 2000. Ontong Java plateau and late Neogene changes in Pacific plate motion, J. geophys. Res., 105,28 255-28 277.
Wood, R. & Davy, B., 1994. The Hikurangi Plateau, Mar. Geol., 118,153-173." name="eprints.referencetext" />
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<meta content="Gubbins, D." name="DC.creator" />
<meta content="Mao, W." name="DC.creator" />
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<meta content="The shallow structure of the Hikurangi margin, in particular the interface between the Australian Plate and the subducting Pacific Plate, is investigated using the traveltimes of direct and converted seismic phases from local earthquakes. Mode conversions take place as upgoing energy from earthquakes in the subducted slab crosses the plate interface. These PS and SP converted arrivals are observed as intermediate phases between the direct P and S waves. They place an additional constraint on the depth of
the interface and enable the topography of the subducted plate to be mapped across the region.
301 suitable earthquakes were recorded by the Leeds (Tararua) broad-band seismic array, a temporary line of three-component short-period stations, and the permanent
stations of the New Zealand national network. This provided coverage across the land area of southern North Island, New Zealand, at a total of 17 stations. Rays are traced
through a structure parametrized using layered B-splines and the traveltime residuals inverted, simultaneously, for hypocentre relocation, interface depth and seismic velocity.
The results are consistent with sediment in the northeast of the study region and gentle topography on the subducting plate. This study and recent tectonic reconstructions of
the southwest Pacific suggest that the subducting plate consists of captured, oceanic crust. The anomalous nature of this crust partly accounts for the unusual features of the Hikurangi margin, e.g. the shallow trench, in comparison with the subducting margin further north." name="DC.description" />
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<h1 class="ep_tm_pagetitle">A multiphase seismic investigation of the shallow subduction zone, southern North Island, New Zealand</h1>
<p style="margin-bottom: 1em" class="not_ep_block"><span class="person_name">Reading, A.M.</span> and <span class="person_name">Gubbins, D.</span> and <span class="person_name">Mao, W.</span> (2001) <xhtml:em>A multiphase seismic investigation of the shallow subduction zone, southern North Island, New Zealand.</xhtml:em> Geophysical Journal International, 147 (1). pp. 215-226. ISSN 0956-540X</p><p style="margin-bottom: 1em" class="not_ep_block"></p><table style="margin-bottom: 1em" class="not_ep_block"><tr><td valign="top" style="text-align:center"><a href="http://eprints.utas.edu.au/1593/1/Reading_AM_et_al_2001.pdf"><img alt="[img]" src="http://eprints.utas.edu.au/style/images/fileicons/application_pdf.png" border="0" class="ep_doc_icon" /></a></td><td valign="top"><a href="http://eprints.utas.edu.au/1593/1/Reading_AM_et_al_2001.pdf"><span class="ep_document_citation">PDF</span></a> - Full text restricted - Requires a PDF viewer<br />1628Kb</td><td><form method="get" accept-charset="utf-8" action="http://eprints.utas.edu.au/cgi/request_doc"><input value="2058" name="docid" accept-charset="utf-8" type="hidden" /><div class=""><input value="Request a copy" name="_action_null" class="ep_form_action_button" onclick="return EPJS_button_pushed( '_action_null' )" type="submit" /> </div></form></td></tr></table><div class="not_ep_block"><h2>Abstract</h2><p style="padding-bottom: 16px; text-align: left; margin: 1em auto 0em auto">The shallow structure of the Hikurangi margin, in particular the interface between the Australian Plate and the subducting Pacific Plate, is investigated using the traveltimes of direct and converted seismic phases from local earthquakes. Mode conversions take place as upgoing energy from earthquakes in the subducted slab crosses the plate interface. These PS and SP converted arrivals are observed as intermediate phases between the direct P and S waves. They place an additional constraint on the depth of
the interface and enable the topography of the subducted plate to be mapped across the region.
301 suitable earthquakes were recorded by the Leeds (Tararua) broad-band seismic array, a temporary line of three-component short-period stations, and the permanent
stations of the New Zealand national network. This provided coverage across the land area of southern North Island, New Zealand, at a total of 17 stations. Rays are traced
through a structure parametrized using layered B-splines and the traveltime residuals inverted, simultaneously, for hypocentre relocation, interface depth and seismic velocity.
The results are consistent with sediment in the northeast of the study region and gentle topography on the subducting plate. This study and recent tectonic reconstructions of
the southwest Pacific suggest that the subducting plate consists of captured, oceanic crust. The anomalous nature of this crust partly accounts for the unusual features of the Hikurangi margin, e.g. the shallow trench, in comparison with the subducting margin further north.</p></div><table style="margin-bottom: 1em" border="0" cellpadding="3" class="not_ep_block"><tr><th valign="top" class="ep_row">Item Type:</th><td valign="top" class="ep_row">Article</td></tr><tr><th valign="top" class="ep_row">Keywords:</th><td valign="top" class="ep_row">converted phase, Hikurangi margin, New Zealand, plate topography, subduction zone.</td></tr><tr><th valign="top" class="ep_row">Subjects:</th><td valign="top" class="ep_row"><a href="http://eprints.utas.edu.au/view/subjects/260100.html">260000 Earth Sciences > 260100 Geology</a></td></tr><tr><th valign="top" class="ep_row">Collections:</th><td valign="top" class="ep_row">UNSPECIFIED</td></tr><tr><th valign="top" class="ep_row">ID Code:</th><td valign="top" class="ep_row">1593</td></tr><tr><th valign="top" class="ep_row">Deposited By:</th><td valign="top" class="ep_row"><span class="ep_name_citation"><span class="person_name">Mrs Katrina Keep</span></span></td></tr><tr><th valign="top" class="ep_row">Deposited On:</th><td valign="top" class="ep_row">13 Aug 2007</td></tr><tr><th valign="top" class="ep_row">Last Modified:</th><td valign="top" class="ep_row">30 Jan 2008 15:36</td></tr><tr><th valign="top" class="ep_row">ePrint Statistics:</th><td valign="top" class="ep_row"><a target="ePrintStats" href="/es/index.php?action=show_detail_eprint;id=1593;">View statistics for this ePrint</a></td></tr></table><p align="right">Repository Staff Only: <a href="http://eprints.utas.edu.au/cgi/users/home?screen=EPrint::View&eprintid=1593">item control page</a></p>
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