High resolution geomorphic map of a submerged marginal plateau, northern Lord Howe Rise, east Australian margin  

Authors / CoAuthors

Nichol, S.L. | Heap, A.D. | Daniell, J.

Abstract

High resolution multibeam bathymetry is used to map and interpret seabed geomorphology for part of the northern Lord Howe Rise plateau in the Tasman Sea. A mapping system of geomorphic units and elements is used, extending the previous hierarchy of geomorphic provinces and features used for the Australian margin. The mapped area covers ~25,500 km2 and incorporates broad ridges, valleys and plateaus. Superimposed on these features are clusters of volcanic peaks, smaller ridges, holes, scarps and aprons. An additional characteristic of the seabed in this area is an extensive network of polygonal furrows that cover the plateaus and the lower slopes of larger ridges. These furrows are formed in stiff, unconsolidated carbonate ooze that forms a near-continuous sediment cover across the area. Peaks are the only geomorphic feature not fully draped in pelagic ooze. The distribution of geomorphic units suggests strong controls from underlying geological structures. In water depths of 1400 m to 1600 m some peaks occur in clusters on ridges that sit above acoustic basement highs and volcanic intrusions. Elsewhere, broad plains and valleys slope to the southwest following the regional dip of the Lord Howe Rise plateau. In contrast, localised geomorphic elements such as moats and holes have likely explanation in terms of spatial variations in sedimentation rates in relation to bathymetric highs. Polygonal furrows are attributed to dewatering processes. The geomorphology of the seabed mapped in this study incorporates examples of forms that have not been previously mapped in such detail on the Australian margin. These are unlikely to be unique to the mapped area of the Lord Howe Rise and can be expected to occur elsewhere on the Rise and presumably on other parts of the Australian margin with a similar geological history.

Product Type

nonGeographicDataset

eCat Id

70053

Contact for the resource

Digital Object Identifier

http://dx.doi.org/10.1016/j.dsr2.2010.10.045

Keywords

• External PublicationScientific Journal Paper

( Theme )

• bathymetry

( Theme )

• marine survey

( Theme )

• morphology

( Theme )

• seabed

( Theme )

• marine

• AU-NSW

Australian and New Zealand Standard Research Classification (ANZSRC)

• Earth Sciences

• Published_External

Publication Date

2010-01-01T00:00:00

Creation Date

Security Constraints

Australian Government Security ClassificationSystem    

Classification - unclassified

Legal Constraints

Creative Commons Attribution 4.0 International Licence    

Access - license

Use - license

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Purpose

Maintenance Information

unknown

Topic Category

geoscientificInformation

Series Information

Vol: 58

Lineage

Unknown

Parent Information

Extents

[-28.0, -25.9, 160.0, 162.0]

Reference System

Spatial Resolution

Service Information

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