Article
Geochemistry & Geophysics
Farzaneh Aziz Zanjani, Guoqing Lin, Clifford H. Thurber
Summary: The study repositions a large number of seismic activities along the Hikurangi subduction zone (HSZ) using a newly developed 3D model, revealing new insights such as the differences in characteristics between upper and lower seismic planes and the possible formation of fluid-rich channels at plate boundaries. Additionally, the mantle wedge in the Taupo volcanic zone (TVZ) exhibits some characteristic velocity anomalies.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geosciences, Multidisciplinary
Dan Bassett, Gou Fujie, Shuichi Kodaira, Ryuta Arai, Yojiro Yamamoto, Stuart Henrys, Dan Barker, Andrew Gase, Harm Van Avendonk, Nathan Bangs, Hannu Seebeck, Brook Tozer, Katie Jacobs, Thomas Luckie, David Okaya, Kimi Mochizuki
Summary: Marine seismic data reveals the distribution of seamounts, sediment cover sequence, and crustal structure along the Hikurangi Plateau. Gravity data suggest that the variation in crustal thickness may be related to deformation and lithospheric extension. The variability in crustal thickness plays a significant role in plate boundary configuration and stress distribution.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geochemistry & Geophysics
Jefferson Yarce, Anne F. Sheehan, Steven Roecker
Summary: Slow slip events occur every 18-24 months in the northern Hikurangi margin of New Zealand and last for several weeks. The Regressive ESTimator algorithm was used to detect seismic events and determine the relationship between slow slip events and earthquakes. The auto-detector found more than three times the number of events compared to manual detection. An increase in earthquake occurrence rate was observed during the 2014 slow slip event.
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
(2023)
Article
Environmental Sciences
Li Yan, Yanling Sun, Meng Li, Ahmed El-Mowafy, Lei Ma
Summary: Slow slip events (SSEs) are geophysical phenomena that occur primarily in subduction zones and are often associated with seismic activity. In this study, SSEs and seismic activity in New Zealand's North Island were investigated. The results showed that SSE1 and SSE7 had larger cumulative slips and surface displacements, leading to a noticeable increase in seismic frequency. The other six SSEs, although characterized by smaller slips, also resulted in an upward trend in seismic frequency in their respective main slip regions. Monitoring shallow SSEs may contribute to identifying and recording seismic activity.
Article
Geochemistry & Geophysics
Jefferson Yarce, Anne Sheehan, Steven Roecker, Kimihiro Mochizuki
Summary: Researchers investigated the seismic velocity structure of the Hikurangi margin in New Zealand and discovered two high Vp/Vs anomalies, which may be related to high pore fluid pressures from subducted sediments and could trigger slow slip events. The findings suggest that subduction processes in the Hikurangi margin are highly dependent on physical features such as subducted seamounts and fluid-rich sediments.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Andrew C. Gase, Harm J. A. Van Avendonk, Nathan L. Bangs, Dan Bassett, Stuart A. Henrys, Daniel H. N. Barker, Shuichi Kodaira, Katrina M. Jacobs, Thomas W. Luckie, David A. Okaya, Gou Fujie, Yojiro Yamamoto, Adrien F. Arnulf, Ryuta Arai
Summary: The study explores the crustal structure and accretion dynamics of the northern Hikurangi margin using new seismic data, revealing the significant impact of volcanic cover on seismic reflectivity and variations in frontal prism structure that may be related to different sediment supply or past seamount collisions.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geosciences, Multidisciplinary
Dan Bassett, Adrien Arnulf, Stuart Henrys, Dan Barker, Harm Avendonk, Nathan Bangs, Shuichi Kodaira, Hannu Seebeck, Laura Wallace, Andrew Gase, Thomas Luckie, Katie Jacobs, Brook Tozer, Ryuta Arai, David Okaya, Kimi Mochizuki, Gou Fujie, Yojiro Yamamoto
Summary: Marine multichannel and wide-angle seismic data were used to study the crustal structure along a 530 km margin-parallel transect of the Hikurangi subduction zone. The research found that the subducting Hikurangi Plateau crust is about 1 km thicker and has slightly higher mantle velocities beneath the south/central Hikurangi compared to the north Hikurangi. In the overthrusting plate, there is a significant reduction in forearc wavespeeds from south to north, accompanied by a change in seismic reflection character. The study suggests that the geological architecture of the overthrusting plate contributes to spatial variability in the location of shallow frictional transitions along the Hikurangi margin, impacting seismic and tsunami hazard.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geology
William S. Bailey, Adam D. McArthur, William D. McCaffrey
Summary: This study is the first to document contourite drift development along the Hikurangi subduction margin of New Zealand. Five classes of drift are recognized, occurring in three principal associations, indicating that the presence of contourites depends on the orientation and strength of oceanographic bottom currents.
Article
Geochemistry & Geophysics
Maomao Wang, Philip M. Barnes, Julia K. Morgan, Rebecca E. Bell, Gregory F. Moore, Ming Wang, Ake Fagereng, Heather Savage, Davide Gamboa, Robert N. Harris, Stuart Henrys, Joshu Mountjoy, Anne M. Trehu, Demian Saffer, Laura Wallace, Katerina Petronotis
Summary: Calcareous rocks are commonly found in subduction zones, but little is known about their consolidation and compactive deformation prior to subduction and the potential effects on subduction and accretionary processes. This study investigates the structure, growth history, and slip rates of normal faults in the pelagic sedimentary sequences of the Hikurangi Margin using drilling data and seismic reflection data. The faults exhibit a polygonal structure and are closely spaced and layer-bound within sequences dominated by pelagic carbonate and calcareous mudstone. Kinematic modeling and displacement analysis show that fault throws decrease toward the upper and lower tipline, and there are lateral variations in physical properties. The polygonal fault system likely formed due to diagenetically induced shear failure and volumetric contraction of the pelagic unit associated with fluid escape.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geochemistry & Geophysics
Tomoaki Nishikawa, Takuya Nishimura
Summary: Research has found that slow slip events (SSEs) at subduction zone plate boundaries can trigger earthquake swarms and megathrust earthquakes. The current statistical models do not explicitly consider the seismicity-triggering effect of SSEs, resulting in failed earthquake predictions. In this study, a new statistical model named the SSE-modulated ETAS model was constructed by incorporating SSE moment rates into the original ETAS model. Application of this new model to SSEs and M 2.5 or greater earthquakes in the Hikurangi Trench, New Zealand showed significant improvement compared to the original model.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Dan Bassett, Adrien Arnulf, Shuichi Kodaira, Ayako Nakanishi, Alistair Harding, Gregory Moore
Summary: By integrating two-decades of onshore-offshore, ocean-bottom seismometer, and passive-source data, this study provides high-resolution 3-D constraints on the architecture of the Nankai subduction zone. The results reveal significant variability in the width of the outer-forearc and the location of the crustal backstop, which have implications for shallow slow-earthquakes and co-seismic slip. The study also highlights the influence of crustal-scale architecture on the width and behavior of the seismogenic zone at Nankai Trough.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Jenny S. Nakai, Anne F. Sheehan, Rachel E. Abercrombie, Donna Eberhart-Phillips
Summary: Using seismometers on the ocean floor and on land, seismic attenuation near the Hikurangi trench offshore New Zealand was investigated. The study revealed high attenuation above a recurring shallow slow-slip event and within the subducting Hikurangi Plateau. The presence of high temperatures, melt, fluids, and fractures in the region was inferred through the analysis of seismic attenuation.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Multidisciplinary Sciences
Pasan Herath, Tim A. Stern, Martha K. Savage, Dan Bassett, Stuart Henrys
Summary: New wide-angle seismic reflection data from offshore New Zealand reveal a more complex lithosphere-asthenosphere boundary (LAB) than previously believed. The LAB zone, approximately 10-12 km thick, contains three distinct layers, including a 3 (+/- 1) km thick layer with azimuthal anisotropy and a 9 (+/- 2) km thick channel with low VP channel. These findings suggest the presence of partial melt, which reduces resistance for plate motion and indicates strain localization due to melt accumulation.
Article
Geosciences, Multidisciplinary
Richard G. Davy, Laura Frahm, Rebecca Bell, Ryuta Arai, Daniel H. N. Barker, Stuart Henrys, Nathan Bangs, Joanna Morgan, Michael Warner
Summary: Full-waveform inversion (FWI) technology can resolve subsurface physical properties to high resolutions, and high-frequency FWI can directly generate high-fidelity reflection images, which are consistent with conventional reflection images and help to better resolve horizons.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geochemistry & Geophysics
Kimihiro Mochizuki, Stuart Henrys, Daisuke Haijima, Emily Warren-Smith, Bill Fry
Summary: Through the deployment of Ocean Bottom Seismographs along the northern Hikurangi subduction zone in New Zealand, researchers located 2005 earthquakes and obtained detailed 3-D models for Vp and Vs. They found high Vp/Vs and low Vp/Vs regions, with seismicity concentrated in areas with high Vp/Vs. The variations in Vp/Vs structure along the subducting Hikurangi Plateau may be influenced by dehydration processes caused by reactivated bending-related faults.
EARTH AND PLANETARY SCIENCE LETTERS
(2021)
Article
Energy & Fuels
S. Sherburn, S. M. Sewell, S. Bourguignon, W. Cumming, S. Bannister, C. Bardsley, J. Winick, J. Quinao, I. C. Wallis
Article
Geosciences, Multidisciplinary
E. A. Bertrand, T. G. Caldwell, S. Bannister, S. Soengkono, S. L. Bennie, G. J. Hill, W. Heise
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
(2015)
Article
Geochemistry & Geophysics
Donna Eberhart-Phillips, Martin Reyners, Stephen Bannister
SEISMOLOGICAL RESEARCH LETTERS
(2015)
Article
Geochemistry & Geophysics
Donna Eberhart-Phillips
BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA
(2016)
Article
Geosciences, Multidisciplinary
Stephen Bannister, Steven Sherburn, Sandra Bourguignon
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
(2016)
Article
Geology
S. Ellis, C. Williams, J. Ristau, M. Reyners, D. Eberhart-Phillips, L. M. Wallace
NEW ZEALAND JOURNAL OF GEOLOGY AND GEOPHYSICS
(2016)
Article
Geology
J. Feenstra, C. Thurber, J. Townend, S. Roecker, S. Bannister, C. Boese, N. Lord, S. Bourguignon, D. Eberhart-Phillips
NEW ZEALAND JOURNAL OF GEOLOGY AND GEOPHYSICS
(2016)
Article
Geochemistry & Geophysics
Donna Eberhart-Phillips, Stephen Bannister, Martin Reyners
GEOPHYSICAL JOURNAL INTERNATIONAL
(2017)
Article
Geochemistry & Geophysics
Donna Eberhart-Phillips, Bill Fry
PHYSICS OF THE EARTH AND PLANETARY INTERIORS
(2017)
Article
Geochemistry & Geophysics
Donna Eberhart-Phillips, Martin Reyners, Phaedra Upton, David Gubbins
GEOPHYSICAL JOURNAL INTERNATIONAL
(2018)
Article
Geochemistry & Geophysics
Donna Eberhart-Phillips, Bill Fry
PHYSICS OF THE EARTH AND PLANETARY INTERIORS
(2018)
Article
Geosciences, Multidisciplinary
F. Lanza, C. J. Chamberlain, K. Jacobs, E. Warren-Smith, H. J. Godfrey, M. Kortink, C. H. Thurber, M. K. Savage, J. Townend, S. Roecker, D. Eberhart-Phillips
GEOPHYSICAL RESEARCH LETTERS
(2019)
Article
Geochemistry & Geophysics
Martin Reyners, Donna Eberhart-Phillips, Stephen Bannister
EARTH AND PLANETARY SCIENCE LETTERS
(2017)
Article
Geochemistry & Geophysics
S. Ellis, R. Van Dissen, D. Eberhart-Phillips, M. Reyners, J. F. Dolan, A. Nicol
EARTH AND PLANETARY SCIENCE LETTERS
(2017)
Article
Geochemistry & Geophysics
Martin Reyners, Donna Eberhart-Phillips, Phaedra Upton, David Gubbins
EARTH AND PLANETARY SCIENCE LETTERS
(2017)
Article
Geochemistry & Geophysics
Lingyu Zhang, Kristoffer Szilas
Summary: This study presents new petrological and geochemical data for the Narssaq Ultramafic Body (NUB) in the Itsaq Gneiss Complex of SW Greenland. The results indicate that the ultramafic rocks of NUB are not mantle residues, but instead represent crustal cumulates derived from high-Mg magmas.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Rong Xu, Sarah Lambart, Oliver Nebel, Ming Li, Zhongjie Bai, Junbo Zhang, Ganglan Zhang, Jianfeng Gao, Hong Zhong, Yongsheng Liu
Summary: This study investigated the iron isotope compositions of Cenozoic basalts in Southeast China, finding significant variations related to different types of basalts and their respective sources.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
C. J. Ebinger, Miriam C. Reiss, Ian Bastow, Mary M. Karanja
Summary: The East African rift system is formed above mantle upwellings and the formation of rifts is related to lithospheric thinning and magmatic activity. The amount of splitting varies spatially and the fast axes are predominantly parallel to the orientation of the rifts. Thick lithospheric modules have less splitting and different orientations, which may indicate mantle plume flow. Splitting rotates and increases in strength as it enters the rift zones, suggesting that the anisotropy is mainly present at shallow depths.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Correction
Geochemistry & Geophysics
Ekaterina Rojas-Kolomiets, Owen Jensen, Michael Bizimis, Gene Yogodzinski, Lukas Ackerman
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Robert W. Nicklas, Igor S. Puchtel, Ethan F. Baxter
Summary: Oxygen fugacity is a fundamental parameter for understanding redox processes in igneous systems. This study compares the Fe-XANES oxybarometry method with the V-in-olivine method for evaluating fO(2) in MORB lavas. The results show that the V-in-olivine method is not applicable to samples with low MgO content, and that the majority of Archean komatiite sources have lower fO(2) than modern MORB.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Chunfei Chen, Stephen F. Foley, Sebastian Tappe, Huange Ren, Lanping Feng, Yongsheng Liu
Summary: The volatile components CO2 and H2O play a major role in mantle melting and heterogeneity. In this study, Ca isotopes were used to trace the lithological heterogeneity in alkaline magmatic rocks. The results revealed the presence of K-richterite and carbonate components as the source of alkaline magmas with low delta 44/40Ca values. These findings highlight the importance of Ca isotopes as a robust tracer of lithological variation caused by volatiles in the Earth's upper mantle.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Timothee Jautzy, Gilles Rixhon, Regis Braucher, Romain Delunel, Pierre G. Valla, Laurent Schmitt, Aster Team
Summary: Although the current approach to estimate catchment-wide denudation rates using only 10Be concentrations has made significant progress in geomorphology, this study argues for the inclusion of 26Al measurements and testing of steady-state assumptions in slow eroding, formerly glaciated landscapes. The study conducted measurements of both 10Be and 26Al in stream sediments from the Vosges Massif in France and found that elevation, slope, channel steepness, and precipitation were the primary factors controlling denudation rates. The study also revealed a significant relationship between the extent of past glaciation and the cosmogenic (un-)steadiness in the stream sediments.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)
Article
Geochemistry & Geophysics
Erik van der Wiel, Douwe J. J. van Hinsbergen, Cedric Thieulot, Wim Spakman
Summary: Numerical models of Earth's mantle dynamics can predict the vigour and mixing of mantle flow, and the average slab sinking rates are an unexplored parameter that can provide intrinsic information on these characteristics. Through numerical experiments, it has been found that slab sinking rates are strongly correlated with mantle convection and mixing, and may explain geochemical observations from hotspot volcanoes.
EARTH AND PLANETARY SCIENCE LETTERS
(2024)