A compilation of grainsize, biogenic silica and carbonate data from East Antarctic surface sediments

Authors / CoAuthors

Post, A.L.

Abstract

Sediment grainsize and compositional data is presented for the East Antarctic region (30-150ÂºE) south of 60ÂºS to provide insight into the nature of habitats available for benthic communities. This compilation of sedimentary properties incorporates data collected and analysed from the 1950s to 2012. Sediment grainsize data is presented from quantitative analyses (472 samples) and Folk classifications (an additional 192 samples), and composition data is presented for calcium carbonate (255 samples) and biogenic silica (304 samples). Sedimentary properties are a key environmental layer for understanding the nature and diversity of benthic habitats. In this report, sediment grainsize and composition data are overlain on maps of bathymetry and geomorphic features, to further illustrate key variations in seabed habitats. The Antarctic shelf is typically dissected by deep troughs and channels, and these form sediment depocenters for fine grained biosiliceous material. Shelf banks, by contrast, are typically composed of coarser sands and gravels due to their exposure to stronger currents and frequent iceberg scouring. The continental slope is heavily eroded into rugged canyons which also contain coarser sediments due to reworking by down slope processes. In several regions, high carbonate content occurs at the shelf break, associated with areas of known hydrocoral occurrence. These variations in physical properties across the Antarctic shelf and slope create distinct habitats for seabed communities. Maps of sediment type, together with broader-scale maps of geomorphic features, can therefore guide understanding of the nature and distribution of seabed habitats in East Antarctica, and particularly within the seven proposed Marine Protected Areas (MPAs) within this region. Sedimentary and geomorphic properties are shown to be highly variable within these MPAs, indicating that these areas likely support a wide variety of benthic communities.

Product Type

document

eCat Id

75087

Contact for the resource

Custodian

EGD

Owner

Commonwealth of Australia (Geoscience Australia)

Custodian

Commonwealth of Australia (Geoscience Australia)
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia

Keywords

GA PublicationRecord

( Theme )

antarctica

( Theme )

marine

( Theme )

sedimentology

Australian and New Zealand Standard Research Classification (ANZSRC)

Environmental Science and Management

Published_External

Publication Date

2013-01-01T00:00:00

Creation Date

Security Constraints

Australian Government Security ClassificationSystem

Classification - unclassified

Legal Constraints

Creative Commons Attribution 4.0 International Licence

Access - license

Use - license

Status

Purpose

Maintenance Information

notPlanned

Topic Category

oceans

Series Information

Record 2013/005

Lineage

This was produced in-house for project requirements.

Parent Information

Extents

[-75.0, -60.0, 30.0, 160.0]

Reference System

WGS 84 (EPSG:4326)

Spatial Resolution

Service Information

Associations

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