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

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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The influence of sea level and cyclones on Holocene reef flat development: Middle Island, central Great Barrier Reef

Coral Reefs ◽

10.1007/s00338-016-1453-9 ◽

2016 ◽

Vol 35 (3) ◽

pp. 805-818 ◽

Cited By ~ 8

Author(s):

E. J. Ryan ◽

S. G. Smithers ◽

S. E. Lewis ◽

T. R. Clark ◽

J. X. Zhao

Keyword(s):

Great Barrier Reef ◽

Sea Level ◽

Reef Flat ◽

Barrier Reef ◽

Holocene Reef

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The influence of coral reefs on atmospheric dimethylsulphide over the Great Barrier Reef, Coral Sea, Gulf of Papua and Solomon and Bismarck Seas

Marine and Freshwater Research ◽

10.1071/mf04097 ◽

2005 ◽

Vol 56 (1) ◽

pp. 85 ◽

Cited By ~ 32

Author(s):

Graham B. Jones ◽

Anne J. Trevena

Keyword(s):

Coral Reefs ◽

Great Barrier Reef ◽

Regional Differences ◽

Reef Coral ◽

Tidal Height ◽

Barrier Reef ◽

Trade Winds ◽

Coral Sea ◽

Gulf Of Papua ◽

High Winds

Marked regional differences in dissolved dimethylsulphide (DMS), atmospheric DMS and DMS flux were recorded during July 1997 through the northern Great Barrier Reef, Coral Sea, Gulf of Papua, Solomon and Bismarck Seas. Highest concentrations of dissolved DMS occurred in the Coral Sea, Gulf of Papua and Bismarck Sea, with lower concentrations in the Great Barrier Reef and Solomon Sea. Elevated levels of atmospheric DMS often occurred in south-easterly to southerly trade winds sampled in the region 18°32′–8°12′S to 145°–151°E, where the highest biomass of coral reefs occurred. Atmospheric DMS often increased in the day after low tides and was positively correlated with tidal height in the northern Great Barrier Reef (r = 0.91, P < 0.05). For tides less than 1.6 m, atmospheric DMS increased on the rising tide for the northern GBR and NW Coral Sea (r = 0.66; P < 0.05) and for the whole voyage (r = 0.25; P < 0.05). As coral reefs have been identified as significant sources of DMS, it is suggested that the daytime increase in atmospheric DMS over much of the study area was mainly a result of high winds and extremely low tides in July, which exposed the reefs during the day.

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Reef-flat and back-reef development in the Great Barrier Reef caused by rapid sea-level fall during the Last Glacial Maximum (30–17 ka)

Geology ◽

10.1130/g46792.1 ◽

2019 ◽

Vol 48 (1) ◽

pp. 39-43 ◽

Cited By ~ 2

Author(s):

Kazuhiko Fujita ◽

Noriko Yagioka ◽

Choko Nakada ◽

Hironobu Kan ◽

Yosuke Miyairi ◽

...

Keyword(s):

Great Barrier Reef ◽

Sea Level ◽

Last Glacial Maximum ◽

Reef Flat ◽

Barrier Reef ◽

Back Reef ◽

Last Glacial ◽

Reef Environments ◽

The Last Glacial Maximum ◽

The Last Glacial

Abstract Reef growth patterns and the development of associated environments have been extensively studied from reef deposits from Holocene and previous interglacial highstands. However, reefs that grew during glacial lowstands are comparatively poorly understood. Here we show the formation of reef-flat and back-reef environments following rapid sea-level fall (15–20 mm yr−1 and 20–40 m in magnitude) during the Last Glacial Maximum (LGM) on the present shelf edge of the Great Barrier Reef. Sedimentological and foraminiferal analyses of unconsolidated reef sediments recovered in cores 111–140 m below sea level at Hydrographers Passage during Integrated Ocean Drilling Project (IODP) Expedition 325 reveal the occurrence of a benthic foraminiferal assemblage dominated by the genera Calcarina and Baculogypsina, which is common in modern reef-flat and back-reef environments in the Great Barrier Reef and elsewhere. This assemblage is associated with higher foraminiferal proportions in reef sediments and higher proportions of well-preserved Baculogypsina tests in the same intervals, which also characterize reef-flat environments. Radiocarbon (14C–accelerator mass spectrometry) ages of reef-flat dwelling foraminifers (n = 22), which indicate the time when these foraminifers were alive, are consistent with the timing of the two-step sea-level fall into the LGM as defined by the previously published well-dated coralgal record. This foraminiferal evidence suggests the development of geomorphically mature fringing reefs with shallow back-reef lagoons during the LGM. Our results also imply that back-reef sediment accumulation rates during the LGM lowstand were comparable to those during the Holocene highstand.

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