Sea level control of stacked late Quaternary coastal sequences, central Great Barrier Reef

ABSTRACT The Great Barrier Reef (GBR) is the world's largest extant mixed silicilastic–carbonate margin. Previous research on the Great Barrier Reef has suggested that the extensive barrier reef system may act as an impermeable barrier and limit the development of delta systems during lowstands, but sufficient geophysical data to support this hypothesis are lacking. We use dense sparker seismic and sub-bottom profiler data to better understand the structure of a large lobe-shaped feature (∼ 10 km × 10 km) on the shelf edge of the central GBR and the interactions between siliciclastic and carbonate sedimentary systems. Interpreted sparker seismic contains prograding clinoforms and suggest that the lobe-shaped feature was a river-dominated shelf-edge delta. A delta on the shelf edge implies that the presence of an exposed barrier reef was not a major impediment to deposition and that other adjacent lobe-shaped features are also deltaic deposits. The shelf-edge deltas were deposited onto a broad upper-slope terrace that allowed continued progradation and limited incision when sea level fell below the shelf edge. Delta foresets are commonly colonized by coral reefs, but the spatial and temporal relationship between reefs and some deltaic units remains unclear. The presence of multiple shelf-edge deltas that link to previously mapped Burdekin River paleo-channels indicates a complex history of sedimentation, with the Burdekin River delta migrating up to 100 km along the GBR margin during the late Quaternary. Regional bathymetric data suggest that large modern or recent shelf-edge deltas are rare on the GBR and that there was a broad range of sedimentary processes operating along the margin of the GBR during periods of low sea level.

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Water circulation around Britomart Reef, Great Barrier Reef, during July 1979

Marine and Freshwater Research ◽

10.1071/mf9800415 ◽

1980 ◽

Vol 31 (4) ◽

pp. 415 ◽

Cited By ~ 13

Author(s):

E Wolanski ◽

M Jones

Keyword(s):

Great Barrier Reef ◽

Sea Level ◽

Central Region ◽

Reef Flat ◽

Water Circulation ◽

Barrier Reef ◽

Trade Winds ◽

Sea Breezes ◽

Coral Sea ◽

Sea Level Oscillations

Weather and currents at eight sites were measured and drogue trajectories obtained in July 1979 at Britomart Reef, a middle reef located at 18�16'S.,146� 38'E. in the central region of the Great Barrier Reef province. The longest current records (3 weeks) were obtained at two sites in passes between the Coral Sea and the Great Barrier Reef Lagoon where westerly currents modulated by tides were observed. Analysis of residuals also showed the importance of wind-driven secondary circulation. Non-tidal sea-level oscillations were very small. Shorter current records (1-10 days) at six sites in the lagoon and on the reef flat showed a predominant northerly flow, also modulated by tides and wind. A residual anticlockwise water circulation existed in the lagoon where flushing was controlled more by winds than by tides. The rise in sea level over the reef flat as a result of waves breaking was negligible. Temperature differences between air and water accounted for the cooling of the water column during the expedition. Constant south-east trade winds were experienced at the reef, while on land the wind was weaker. more variable, and often dominated by land-sea breezes.

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Holocene sea level and climate variability on the Great Barrier Reef, Australia

10.14264/uql.2017.168 ◽

2017 ◽

Cited By ~ 1

Author(s):

Nicole Leonard

Keyword(s):

Climate Variability ◽

Great Barrier Reef ◽

Sea Level ◽

Barrier Reef ◽

Holocene Sea Level

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Holocene sea level instability in the southern Great Barrier Reef, Australia: high-precision U–Th dating of fossil microatolls

Coral Reefs ◽

10.1007/s00338-015-1384-x ◽

2015 ◽

Vol 35 (2) ◽

pp. 625-639 ◽

Cited By ~ 21

Author(s):

Nicole D. Leonard ◽

J-x Zhao ◽

K. J. Welsh ◽

Y-x Feng ◽

S. G. Smithers ◽

...

Keyword(s):

Great Barrier Reef ◽

Sea Level ◽

High Precision ◽

Barrier Reef ◽

Holocene Sea Level

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Water circulation and shelf waves in the northern Great Barrier Reef lagoon

Marine and Freshwater Research ◽

10.1071/mf9810721 ◽

1981 ◽

Vol 32 (5) ◽

pp. 721 ◽

Cited By ~ 25

Author(s):

E Wolanski ◽

B Ruddick

Keyword(s):

Great Barrier Reef ◽

Sea Level ◽

Low Frequency ◽

Current Data ◽

Barrier Reef ◽

Sea Levels ◽

The North ◽

Level Data ◽

Shelf Wave ◽

Salinity Water

Currents and sea levels were measured at a number of locations in the Great Barrier Reef (GBR) lagoon from about 10 to 13� S., during the period October-December 1979. A strong non-tidal, low-frequency modulation of all sea-level and current data was found. The currents nearshore were driven northward by the wind, and then at least partially blocked by the dense network of reefs to the north of 10� s. The water then flowed southward in deeper water adjacent to the reef, driven by a longshore pressure gradient. The low- frequency sea-level data, though not the current records, showed northward phase propagation at speeds characteristic of a first-mode shelf wave trapped in the lagoon between the shore and the reef. Data are presented revealing the intrusion of low-salinity water, through Bligh Entrance, in the GBR lagoon, as a result of river discharges in the Gulf of Papua. It is suggested that low-frequency longshore currents may periodically flush these river plumes from the GBR lagoon and enhance interaction between reefs. In the Coral Sea in front of reef passages, the large horizontal velocities may result in forces upwelling by selective withdrawal and jet entrainment.

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Continental shelf waves and their influence on the circulation around the Great Barrier Reef

Marine and Freshwater Research ◽

10.1071/mf9830023 ◽

1983 ◽

Vol 34 (1) ◽

pp. 23 ◽

Cited By ~ 24

Author(s):

E Wolanski ◽

AF Bennett

Keyword(s):

Continental Shelf ◽

Great Barrier Reef ◽

Sea Level ◽

Atmospheric Pressure ◽

Low Frequency ◽

Internal Tides ◽

Wind Component ◽

Barrier Reef ◽

Longshore Current ◽

Shelf Waves

Winds and atmospheric pressure, sea level and water currents were measured at several locations over the continental shelf, both east and west of the Great Barrier Reef, between 14.5�s. and 20�S., from June to November 1980. The dominant wind direction changed from westward over the Coral Sea to north- westward (roughly parallel to the shore) over the shelf. A strong non-tidal low-frequency signal in all sea- level and longshore current data was found, highly coherent from site to site and strongly correlated with the longshore wind component over the shelf, though not with the atmospheric pressure. A model of wind- driven barotropic shelf waves is used to explain a number of observations, such as the invariance of temporal fluctuations of longshore current with distance from shore, and the northward longshore propagation of oceanic disturbances at a speed equal to twice that of the first-mode barotropic free shelf wave, a speed one order of magnitude smaller than that of the wind system. The low-frequency current fluctuations resulted in large water displacements, up and down the coast. Low-frequency cross-shelf currents were much weaker and less coherent. Two upwelling mechanisms are internal tides and internal Kelvin waves coupled to the barotropic shelf waves.

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Assessment of the Accuracy of Recent Empirical and Assimilated Tidal Models for the Great Barrier Reef, Australia, Using Satellite and Coastal Data

Remote Sensing ◽

10.3390/rs11101211 ◽

2019 ◽

Vol 11 (10) ◽

pp. 1211 ◽

Cited By ~ 4

Author(s):

Fardin Seifi ◽

Xiaoli Deng ◽

Ole Baltazar Andersen

Keyword(s):

Great Barrier Reef ◽

Sea Level ◽

Root Mean Square ◽

Tide Gauge ◽

Bottom Topography ◽

Deep Ocean ◽

Mean Square ◽

Barrier Reef ◽

In Situ Data ◽

The Impact

The latest satellite and in situ data are a fundamental source for tidal model evaluations. In this work, the satellite missions TOPEX/Poseidon, Jason-1, Jason-2 and Sentinel-3A, together with tide gauge data, were used to investigate the performance of recent regional and global tidal models over the Great Barrier Reef, Australia. Ten models, namely, TPXO8, TPXO9, EOT11a, HAMTIDE, FES2012, FES2014, OSUNA, OSU12, GOT 4.10 and DTU10, were considered. The accuracy of eight major tidal constituents (i.e., K1, O1, P1, Q1, M2, S2, N2 and K2) and one shallow water constituent (M4) were assessed based on the analysis of sea-level observations from coastal tide gauges and altimetry data (TOPEX series). The outcome was compared for four different subregions, namely, the coastline, coastal, shelf and deep ocean zones. Sea-level anomaly data from the Sentinel-3A mission were corrected using the tidal heights predicted by each model. The root mean square values of the sea level anomalies were then compared. According to the results, FES2012 compares more favorably to other models with root mean square (RMS) values of 10.9 cm and 7.7 cm over the coastal and shelf zones, respectively. In the deeper sections, the FES2014 model compares favorably at 7.5 cm. In addition, the impact of sudden fluctuations in bottom topography on model performances suggest that a combination of bathymetric variations and proximity to the coast or islands contributes to tidal height prediction accuracies of the models.

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