Year

2011

Degree Name

Bachelor of Science (Honours)

ANZSRC / FoR Code

0406 PHYSICAL GEOGRAPHY AND ENVIRONMENTAL GEOSCIENCE

Department

School of Earth & Environmental Sciences

Abstract

Mullet creek, located on the south coast of New South Wales terminates in a shallow, wave dominated barrier estuary that developed during the Holocene. Sea level fluctuations have affected the current morphology of Mullet Creek not only in its delta, but also for a distance of approximately 8 km from the coast. During this investigation LiDAR data and subsurface sampling techniques have been used to investigate the alluvial terraces and macro‐channel morphology, and transitional sedimentary sequences in the upstream floodplain and downstream channel reaches.

LiDAR revealed that an alluvial terrace is present in the mid to upper reaches in the Mullet Creek catchment, extending ~7 km from the foothills. This terrace provides evidence of higher sea level and examination of other terraces within the Lake Illawarra catchment indicates that terraces may provide evidence for sea level over two glacial cycles in this area. The results from subsurface sampling showed that the upstream study reach consists of an abandoned channel sequence and a buried Pleistocene floodplain sequence and sampling in the downstream channel reach has provided new evidence that the fluvio‐deltaic sediments do not extent as far upstream of the delta as previously thought. Ground penetrating radar was also trialed in these setting but returned no useful results.

By conducting these investigations, the relationship between sea level, Mullet Creek and its current morphology can be better explain and used to predict how rising sea level will affect the system as a whole.

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