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The geomorphology of the flanks of the Lord Howe Island volcano, Tasman Sea, Australia

Journal Article


Abstract


  • The flanksofmid-oceanvolcanoesareinherentlyunstablefeaturesespeciallyintheconstructionalphase

    of developmentwhenthevolcanoisactive.Lateralandverticalstressesareplacedonthevolcanicedifice

    as itbuilds,withtheflankscontinuingtobeunstableuptoatleast1Maaftervolcanismhasceased.The

    flanksoftheLordHoweIslandvolcanorecordthisperiodofgreatestinstabilityandasubsequentperiodin

    which marineandsubaerialerosionhavedominateditsgeomorphicevolution.LordHoweIslandliesin

    the TasmanSeaoftheSouthernPacificregionandisthesubaerialremnantofaMiocenemid-ocean

    volcano. Theislandhasonlyrecentlyenteredreefbuildingseasandthereforehasbeensubjecttomarine

    erosiveprocessesoverthepast5–6Ma.Theislandisuniqueasitsitsonthestabledrownedcontinental

    crustoftheLordHoweRiseratherthanoceaniccrustlikemanyothermid-platebasalticislands.

    Multibeamsonarbathymetrydatawerecollectedtoadepthof3500mwheretheislandflanksgradeinto

    the surroundingplanarseafloor.Severalslumpfeaturesareevident,thelargestbeingover130km2 in

    area. Thesefeaturesareinferredtobeold(lateTertiary)basedonanextensivecoverofmarinesediment

    as indicatedbylowmultibeambackscatterintensityandsubduedtopography.Mostlikelytheslumps

    formedduringtheimmediatepost-eruptivestageofvolcanoevolution,beforethebulkofthesubaerial

    portionofthevolcanowasremovedbymarineerosion.Flankprocessesarenowdominatedbythe

    depositionofcarbonatesedimentcomposedofmolluscandforaminiferalremains.Basedonradiocarbon

    and stableisotopeanalysesofasedimentcore(760mdepth)collectedonatroughinthecentreofthe

    volcanicedifice,Quaternarysedimentwaslikelydepositedpredominantlyduringglacialperiods.The

    erosionalmorphology,sedimentcoverandtectonicstabilityoftheregionsuggestthattheflanksofthe

    volcano areatpresentrelativelystable.

Authors


  •   Kennedy, David (external author)
  •   Brooke, Brendan P. (external author)
  •   Woodroffe, Colin D.
  •   Jones, Brian G.
  •   Waikari, C (external author)
  •   Nichol, Scott L. (external author)

Publication Date


  • 2011

Citation


  • Kennedy, D., Brooke, B. P., Woodroffe, C. D., Jones, B. G., Waikari, C. & Nichol, S. L. (2011). The geomorphology of the flanks of the Lord Howe Island volcano, Tasman Sea, Australia. Deep-Sea Research Part II: Topical Studies in Oceanography, 58 (7-8), 899-908.

Scopus Eid


  • 2-s2.0-79952815969

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/5234

Has Global Citation Frequency


Number Of Pages


  • 9

Start Page


  • 899

End Page


  • 908

Volume


  • 58

Issue


  • 7-8

Abstract


  • The flanksofmid-oceanvolcanoesareinherentlyunstablefeaturesespeciallyintheconstructionalphase

    of developmentwhenthevolcanoisactive.Lateralandverticalstressesareplacedonthevolcanicedifice

    as itbuilds,withtheflankscontinuingtobeunstableuptoatleast1Maaftervolcanismhasceased.The

    flanksoftheLordHoweIslandvolcanorecordthisperiodofgreatestinstabilityandasubsequentperiodin

    which marineandsubaerialerosionhavedominateditsgeomorphicevolution.LordHoweIslandliesin

    the TasmanSeaoftheSouthernPacificregionandisthesubaerialremnantofaMiocenemid-ocean

    volcano. Theislandhasonlyrecentlyenteredreefbuildingseasandthereforehasbeensubjecttomarine

    erosiveprocessesoverthepast5–6Ma.Theislandisuniqueasitsitsonthestabledrownedcontinental

    crustoftheLordHoweRiseratherthanoceaniccrustlikemanyothermid-platebasalticislands.

    Multibeamsonarbathymetrydatawerecollectedtoadepthof3500mwheretheislandflanksgradeinto

    the surroundingplanarseafloor.Severalslumpfeaturesareevident,thelargestbeingover130km2 in

    area. Thesefeaturesareinferredtobeold(lateTertiary)basedonanextensivecoverofmarinesediment

    as indicatedbylowmultibeambackscatterintensityandsubduedtopography.Mostlikelytheslumps

    formedduringtheimmediatepost-eruptivestageofvolcanoevolution,beforethebulkofthesubaerial

    portionofthevolcanowasremovedbymarineerosion.Flankprocessesarenowdominatedbythe

    depositionofcarbonatesedimentcomposedofmolluscandforaminiferalremains.Basedonradiocarbon

    and stableisotopeanalysesofasedimentcore(760mdepth)collectedonatroughinthecentreofthe

    volcanicedifice,Quaternarysedimentwaslikelydepositedpredominantlyduringglacialperiods.The

    erosionalmorphology,sedimentcoverandtectonicstabilityoftheregionsuggestthattheflanksofthe

    volcano areatpresentrelativelystable.

Authors


  •   Kennedy, David (external author)
  •   Brooke, Brendan P. (external author)
  •   Woodroffe, Colin D.
  •   Jones, Brian G.
  •   Waikari, C (external author)
  •   Nichol, Scott L. (external author)

Publication Date


  • 2011

Citation


  • Kennedy, D., Brooke, B. P., Woodroffe, C. D., Jones, B. G., Waikari, C. & Nichol, S. L. (2011). The geomorphology of the flanks of the Lord Howe Island volcano, Tasman Sea, Australia. Deep-Sea Research Part II: Topical Studies in Oceanography, 58 (7-8), 899-908.

Scopus Eid


  • 2-s2.0-79952815969

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/5234

Has Global Citation Frequency


Number Of Pages


  • 9

Start Page


  • 899

End Page


  • 908

Volume


  • 58

Issue


  • 7-8