Colin WOODROFFE - Research Information

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Reef morphology and sedimentation

Colin Woodroffe has undertaken a number of projects that investigate the morphology and Holocene development of reefs in the Indo-Pacific region, including:

 Lord Howe Island
 Middleton and Elizabeth Reefs
 Torres Strait
 Other Indian Ocean and Pacific Ocean reefs

Lord Howe Island

A series of studies of the sediments, stratigraphy and bathymetry around Lord Howe Island have provided fundamental data about the broad habitats that occur within the Lord Howe Marine Park. Lord Howe Island is a spectacular volcanic island, with a small fringing reef and lagoon, at the southern latitudinal limit to coral-reef growth and in the transition from tropical to temperate carbonate zones. This has been the subject of a broad collaborative, ARC-funded research project led by Colin Woodroffe (Woodroffe et al., 2006).

The calcarenites covering the low-lying central part of the island, formed largely as fossil dunes, and the stratigraphy and chronology of these has been the subject of a PhD thesis by Brendan Brooke (Brooke et al., 2003)

The Holocene evolution of the Lord Howe fringing reef was the subject of a PhD thesis by David Kennedy who showed that reefs flourished 6000 years ago, but that there was a phase of mud sedimentation in the lagoon around 4000 years ago, with replacement by surficial sands in the late Holocene (Kennedy and Woodroffe, 2000).

The development of the spectacular rock coast geomorphology around Lord Howe Island has been the subject of a PhD thesis by Mark Dickson, who has demonstrated that shore platforms form on the less resistant lithology, but that plunging cliffs that occur around much of the island are undergoing little if any recession (Dickson et al., 2004).

Studies on the shelf around Lord Howe Island have identified a fossil reef (Woodroffe et al., 2005), and this will be the focus of a collaborative research cruise with Geoscience Australia aboard the RV Southern Surveyor in 2008.

References

Brooke, B.P., Woodroffe, C.D., Murray-Wallace, C.V., Heijnis, H. and Jones, B.G. (2003) Stratigraphy of the Quaternary eolianite on Lord Howe Island, southwest Pacific Ocean. Quaternary Science Reviews 22, 859-880.

 

Dickson, M.E., Kennedy. D.M. and Woodroffe, C.D. (2004) The influence of rock resistance on coastal morphology around Lord Howe Island, southwest Pacific. Earth Surface Processes and Landforms, 29, 629-643.

 

Kennedy, D.M. and Woodroffe, C.D. (2000) Holocene lagoonal sedimentation at the latitudinal limits of reef growth, Lord Howe Island, Tasman Sea. Marine Geology, 169, 287-304.

 

Woodroffe, C.D., Dickson, M.E., Brooke, B.P., and Kennedy, D.M. (2005) Episodes of reef growth at Lord Howe Island, the southernmost reef in the southwest Pacific. Global and Planetary Change, 49, 222-237.

 

Woodroffe, C.D., Kennedy, D.M., Brooke, B.P. and Dickson, M.E. (2006) Geomorphological evolution of Lord Howe Island and carbonate production at the latitudinal limit to reef growth. Journal of Coastal Research, 22, 188-201.

Elizabeth and Middleton Reefs

The studies on Lord Howe Island have been extended by Colin Woodroffe and Brian Jones to look at sediments across the Lord Howe shelf (Kennedy et al., 2002). The studies have also been extended to Elizabeth and Middleton Reefs, two atolls to the north, which were examined during an oceanographic cruise aboard the RV Franklin in 1998 and Advance II in 2001. Drilling, vibrocoring, seismic profiling and dating indicate that Elizabeth and Middleton Reefs have a Holocene rim of reef framework, enclosing a lagoon partly filled by prograding sand sheets composed of coral, coralline algae, foraminifers and lesser skeletal components. The reef framework of these atolls close to the latitudinal limits for coral growth is very porous, dominated by branching rather than massive corals. Corals established on this around 6700 years BP, implying little if any lag after inundation of the platform by postglacial sea-level rise. Development of reef islands is limited, restricted by the paucity of large coralline debris or cemented conglomerate on which islands can become established. Subsidence of Middleton Reef is interpreted to have been slower than on other atolls because it lies on the margin of the floundered continental crust of the Lord Howe Rise (Woodroffe et al., 2004).

References

Kennedy, D.M., Woodroffe, C.D., Jones, B.G., Dickson, M.E. and Phipps, C.V.G. (2002) Carbonate sedimentation on subtropical shelves around Lord Howe Island and Balls Pyramid, Southwest Pacific. Marine Geology 188, 333-349.

 

Woodroffe, C.D., Kennedy, D.M., Jones, B.G. and Phipps, C.V.G., 2004. Geomorphology and Late Quaternary development of Middleton and Elizabeth Reefs. Coral Reefs, 23: 249-262.

 

Torres Strait

The Holocene evolution of reefs in Torres Strait is of particular interest because they are influenced by strong tidal currents. Preliminary stratigraphical research on the evolution of the reef arounds several islands in Torres Strait was undertaken by Colin Woodroffe and David Kennedy (Woodroffe et al., 2000). Subsequent fieldwork has concentrated on Warraber Island, a reef platform in central Torres Strait, as part of a collaborative ARC-funded project between Colin Woodroffe (University of Wollongong), Peter Cowell (University of Sydney) and Roger McLean (Australian Defence Force Academy). This has focused on processes on the reef platform and the evolution of the reef island examining the sedimentary environments around the reef, and the hydrodynamics and sediment movement across the reef flat, and has produced evidence for the incremental growth of Warraber Island over the past 3000 years (Woodroffe et al., 2007)

References

Woodroffe, C.D., Kennedy, D.M., Hopley, D., Rasmussen, C. and Smithers, S.G. (2000) Holocene reef growth in Torres Strait. Marine Geology 170, 331-346.

 

Woodroffe, C.D., B. Samosorn, Q. Hua, and D.E. Hart (2007) Incremental accretion of a sandy reef island over the past 3000 years indicated by component-specific radiocarbon dating, Geophysical Research Letters, 34, L03602, doi:P10.1029/2006GL028875.

 

Other Indian Ocean and Pacific Ocean reefs

Colin Woodroffe’s research over the past two decades has focused on reef morphology and evolution in the Indian Ocean and Pacific Oceans, with a particular focus on atolls. He undertook a major study on the Cocos (Keeling) Islands in the 1990s. He has undertaken studies in the Maldives, and has reviewed the evolution of reefs in the eastern Indian Ocean (Woodroffe, 2005).

In the Pacific his studies have included many of the islands in Kiribati, particularly Christmas Island (Kiritimati) which is a large atoll (Woodroffe and McLean, 1998). His research focus on these islands also includes an emphasis on the processes by which reef islands form, and the paleoenvironmental information that is contained within corals, especially microatolls, from these environments

References

Woodroffe, C.D. (2005) Late Quaternary sea-level highstands in the central and eastern Indian Ocean: a review. Global and Planetary Change, in press.

 

Woodroffe, C.D. and McLean, R.F. (1998) Pleistocene morphology and Holocene emergence of Christmas (Kiritimati) Island, Pacific Ocean. Coral Reefs 17, 235-248.

 

 

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