Corals and reefs as indicators of paleo-sea levels with special reference to the Great Barrier Reef

1986 ◽  
pp. 195-228 ◽  
Author(s):  
D. Hopley
Keyword(s):  
Great Barrier Reef ◽  
Special Reference ◽  
Barrier Reef ◽  
Sea Levels

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

1981 ◽  
Vol 32 (5) ◽  
pp. 721 ◽  
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.

Sea level change on the Great Barrier Reef: an introduction

1978 ◽  
Vol 291 (1378) ◽  
pp. 159-166 ◽  
Keyword(s):  
Great Barrier Reef ◽  
Sea Level ◽  
Sea Level Change ◽  
North Coast ◽  
Barrier Reef ◽  
Isotopic Dating ◽  
Sea Levels ◽  
Level Change ◽  
Show Evidence ◽  
Eustatic Fluctuations

Evidence for Holocene shorelines from the Queensland coast, off which the Great Barrier Reef lies, has epitomized the problems of eustatic fluctuations over the last 6000 years. While some areas of southern and central Queensland show evidence of no sea level higher than the present over this period, other areas, particularly within 150 km of Townsville on the mid-North coast, have provided radiometrically dated evidence for an emergence of up to 4.9 m. The area in which the 1973 Expedition worked has been described previously by several authors, and evidence for higher shorelines in the form of cemented platforms, raised reefs and related features suggesting higher sea levels, though without isotopic dating, has been noted. Research was aimed at confirming and accurately measuring and dating such evidence and relating it to the pattern described elsewhere. Any divergences must then be explained in terms of spatially and temporally varying oceanographic or geomorphic conditions and Earth movements of tectonic and/or isostatic origin.

Sea level change in the Holocene on the northern Great Barrier Reef

1978 ◽  
Vol 291 (1378) ◽  
pp. 167-186 ◽  
Keyword(s):  
Great Barrier Reef ◽  
Sea Level ◽  
Radiometric Dating ◽  
Barrier Reef ◽  
Sea Levels ◽  
Level Curves ◽  
Level Change ◽  
Fossil Corals ◽  
History Of ◽  
Degree Of Confidence

Detailed studies, utilizing a range of both well controlled sea level criteria and dates, are required if Holocene time-sea level curves are to be established with any degree of confidence. This paper is restricted to an interpretation of Expedition results from the northern Great Barrier Reef, excluding those from the drill core. Extensive colonies of emergent fossil corals in growth position indicate that present sea level was first reached about 6000 a b. p. Elevations of cay surfaces, cemented rubble platforms, microatolls, coral shingle ridges, reef flats and mangrove swamps, referenced to present sea level show an array of heights. However, levels of particular features are accordant on many reefs: it is believed that these can be related to particular sea levels. Radiometric dating provides the time framework. Ages of samples from similar deposits on different reefs are surprisingly consistent. Oscillations in sea level since 6000 a b.p ., relative to present sea level, are identified with varying degrees of confidence. This history of relative sea level does not separate eustatic from noneustatic components.

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