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Submarine sedimentary bedforms and benthos surrounding the Heard and McDonald Islands World Heritage Site

We present highlights of the first multibeam and bottom sampling survey surrounding the UNESCO World Heritage listed Heard and McDonald Islands (HIMI), conducted in the HIMI Marine Reserve InnerMarine Zone. These insular shelf data reveal that persistent eastward flowing currents and retreating glaciers drive patterns of sediment distribution. Sedimentary bedform directionality, corroborated by drifter data, suggest that the prevailing energy in this region dominates from west to east, and is deflected in an anticlockwise direction around Heard Island, causing sediment deposition to be concentrated on the eastern (downcurrent) side of the islands. Sediment bedform morphology likely mirrors the eastward flowing Antarctic Circumpolar Current and oscillating east!west tidal currents. Thick sediment accumulations north of Heard Island may be related to deglaciation since the Last Glacial Maximum.

Sample sites on the northern down-current side of Heard Islands and on the western up-current side of the McDonald Islands contain a diverse range of taxonomic groups compared to all other sample sites. Benthic specimens obtained in rock dredges and sediment grabs show a range of invertebrate species that are likely endemic to the HIMI region.

History

Publication title

Seafloor Geomorphology as Benthic Habitat

Edition

2nd

Editors

P Harris and E Baker

Pagination

705-720

ISBN

9780128149607

Department/School

Institute for Marine and Antarctic Studies

Publisher

Elsevier Science

Place of publication

Sydney

Extent

60

Rights statement

Copyright 2020 Elsevier Inc.

Repository Status

  • Restricted

Socio-economic Objectives

Expanding knowledge in the earth sciences