A Fluid Pulse on the Hikurangi Subduction Margin: Evidence From a Heat Flux Transect Across the Upper Limit of Gas Hydrate Stability

Pecher, Ingo; Villinger, Heinrich; Kaul, Norbert E; Crutchley, G. J.; Mountjoy, Joshu; Huhn, Katrin; Kukowski, Nina; Henrys, S. A.; Rose, P.; Coffin, R. B.

doi:10.1002/2017gl076368

Cited by 50 publications

(32 citation statements)

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“…One possible interpretation of HRZ‐2 is that it represents sedimentary material that is underplated at the base of the upper plate (Figure b). Pecher et al (, ) invoke substantial uplift in the northern region of normal faulting as forming a pronounced double BSR at the base of gas hydrate stability. No clear indication of sediment underplating has been found for the offshore forearc.…”

Section: Discussionmentioning

confidence: 99%

Marine Forearc Extension in the Hikurangi Margin: New Insights From High‐Resolution 3‐D Seismic Data

et al. 2018

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Upper‐plate normal faults are a widespread structural element in erosive plate margins. Increasing coverage of marine geophysical data has proven that similar features also exist in accretionary margins where horizontal compression usually results in folding and thrust faulting. There is a general lack of understanding of the role and importance of normal faulting for the structural and tectonic evolution of accretionary margins. Here we use high‐resolution 2‐D and 3‐D seismic reflection data and derived seismic attributes to map and analyze upper‐plate normal faulting in the marine forearc of the accretionary Hikurangi margin, New Zealand. We document extension of the marine forearc over a wide area along the upper continental slope. The seismically imaged normal faults show low vertical displacements, high dip angles, a preference for landward dip, and often en echelon patterns. We evaluate different processes, which may cause the observed extension, including (1) stress change during the earthquake cycle, (2) regional or local uplift and decoupling of shallow strata from compression at depth, and (3) rotation of crustal blocks and resulting differential stresses at the block boundaries. The results suggest that normal faults play an important role in the structural and tectonic evolution of accretionary margins, including the northern Hikurangi forearc.

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Section: Discussionmentioning

confidence: 99%

Marine Forearc Extension in the Hikurangi Margin: New Insights From High‐Resolution 3‐D Seismic Data

et al. 2018

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“…The past subduction of seamounts may have an effect on fluid pressures at the plate interface (Bell et al, 2010;Ellis et al, 2015). Fluid expulsion, potentially related to subduction of seamounts, has been implicated in observed thermal anomalies that disturb the gas hydrate stability field near the TLC (e.g., Pecher et al, 2017).…”

Section: Tectonic Settingmentioning

confidence: 99%

Creeping Gas Hydrate Slides

Pecher¹,

Barnes²,

LeVay³

2019

Proceedings of the International Ocean Discovery Program

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“…There is no indication of strongly transient thermal conditions, such as the occurrence of “metastable” hydrate resulting in double BSRs in the trough basin (Pegasus Basin). Much further north on the Hikurangi Margin double BSRs indicate pronounced uplift or significant changes in the thermal regime (Pecher et al, ). We therefore have confidence that the BSR is a good indicator for the present‐day thermal regime.…”

Section: Methodsmentioning

confidence: 99%

A 3‐D Model of Gas Generation, Migration, and Gas Hydrate Formation at a Young Convergent Margin (Hikurangi Margin, New Zealand)

Kroeger

Crutchley

Kellett

et al. 2019

Geochem Geophys Geosyst

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We present a three‐dimensional gas hydrate systems model of the southern Hikurangi subduction margin in eastern New Zealand. The model integrates thermal and microbial gas generation, migration, and hydrate formation. Modeling these processes has improved the understanding of factors controlling hydrate distribution. Three spatial trends of concentrated hydrate occurrence are predicted. The first trend (I) is aligned with the principal deformation front in the overriding Australian plate. Concentrated hydrate deposits are predicted at or near the apexes of anticlines and to be mainly sourced from focused migration and recycling of microbial gas generated beneath the hydrate stability zone. A second predicted trend (II) is related to deformation in the subducting Pacific plate associated with former Mesozoic subduction beneath Gondwana and the modern Pacific‐Australian plate boundary. This trend is enhanced by increased advection of thermogenic gas through permeable layers in the subducting plate and focused migration into the Neogene basin fill above Cretaceous‐Paleogene structures. The third trend (III) follows the northern margin of the Hikurangi Channel and is related to the presence of buried strata of the Hikurangi Channel system. The predicted trends are consistent with pronounced seismic reflection anomalies related to free gas in the pore space and strength of the bottom‐simulating reflection. However, only trend I is also associated with clear and widespread seismic indications of concentrated gas hydrate. Total predicted hydrate masses at the southern Hikurangi Margin are between 52,800 and 69,800 Mt. This equates to 3.4–4.5 Mt hydrate/km2, containing 6.33 × 108–8.38 × 108 m3/km2 of methane.

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A Fluid Pulse on the Hikurangi Subduction Margin: Evidence From a Heat Flux Transect Across the Upper Limit of Gas Hydrate Stability

Cited by 50 publications

References 50 publications

Marine Forearc Extension in the Hikurangi Margin: New Insights From High‐Resolution 3‐D Seismic Data

Marine Forearc Extension in the Hikurangi Margin: New Insights From High‐Resolution 3‐D Seismic Data

Creeping Gas Hydrate Slides

A 3‐D Model of Gas Generation, Migration, and Gas Hydrate Formation at a Young Convergent Margin (Hikurangi Margin, New Zealand)

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