Details

Autor(en) / Beteiligte

• Webster, Jody M.
• George, Nicholas P.J.
• Beaman, Robin J.
• Hill, Jon
• Puga-Bernabéu, Ángel
• Hinestrosa, Gustavo
• Abbey, Elizabeth A.
• Daniell, James J.

Titel

Submarine landslides on the Great Barrier Reef shelf edge and upper slope: A mechanism for generating tsunamis on the north-east Australian coast?

Ist Teil von

• Marine geology, 2016-01, Vol.371, p.120-129

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2016

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Shallow (<200m) submarine landslides influence margin evolution and can produce devastating tsunamis, yet little is known about these processes on mixed siliciclastic–carbonate margins. We have discovered seven landslides along the shelf edge and upper slope of the central Great Barrier Reef (GBR), Australia. The largest shelf edge landslide is investigated in detail and represents a collapse of a 7km long section of the shelf edge at 90m water depth with coarse debris deposited up to 5.5km away on the upper slope down to 250m. The precise timing and triggering mechanisms are uncertain but available chronologic and seismic stratigraphic evidence suggests that this event occurred during the last deglacial sea-level rise between 20 and 14ka. Regional bathymetric data confirms that these shelf edge and upper slope slides are restricted to the central GBR between latitude 18° and 19°S, suggesting a spatial relationship between the extensive Burdekin paleo-fluvial/delta system and shallow landslide activity. This study highlights an important local mechanism for the generation of tsunamis on this margin type, and numerical simulations under present conditions confirm that a 2 to 3m tsunami wave could be produced locally. However, we consider that the risk of such slides, and their resulting tsunamis, to the modern coastline is negligible due to their relatively small size and the capacity of the GBR to dissipate the wave energy. [Display omitted] •Shallow (<200m) submarine landslides discovered along the edge of the GBR•Slides restricted to central GBR, near the region's largest paleo-delta system•Largest shelf edge landslide occurred during the last deglacial sea-level rise.•Numerical simulations show a 2–3m tsunami wave proximal to the slide.•Current tsunami risk negligible because the GBR dissipates the wave energy.