Is it blatant scaremongering?

Submitted by Webmaster on Wed, 11/05/2005 - 22:53

To quote a representative of the False Cape developers, as reported in the Cairns Post, Tuesday 3 May 2005. “No wonder people are getting upset, it’s blatant scaremongering,”  Mr Lamprell said.  He challenged CAFNEC and the other groups to come up with geotechnical evidence that backed up their safety concerns.  As you requested Mr Lamprell.  The following information comes from a report called “Community Risk in Cairns” by the Australian Geological Survey organisation.  The purpose of this report was to identify geologically hazardous area with a view to reduction of community vulnerability.One definite, and two probable large debris flow events [landslides] are known to have occurred in the Cairns regions since European settlement...  The probable debris flow events happened in 1878 and 1911 on the eastern side of Trinity Inlet.  Deposits from numerous debris flows have been identified in this area. On 8 March 1878, a “flood” followed by a severe cyclone triggered many landslides across the Inlet. They could be heard distinctly in Cairns (Jones, 1976). On 1 April 1911, a big landslide occurred in the Nisbet Range, also across the Inlet from Cairns. The scar could be seen in photos for several years afterwards (A. Broughton, Cairns Historical Society, personal communication, 1997). This landslide brought away trees, rocks and everything else from a considerable distance up the mountain side (Cairns Post, 3 April 1911)…[Regarding the nature of debris flows], the proximal portion is that part of the debris flow closest to the source of the landslide. It has a lumpy or convex surface and contains large boulders up to several metres in length. The distal portion of a debris flow is the more gently sloping and contains the finer grained, thinner sediments that are deposited further from the landslide source. Individual debris flows large enough to run out on to the plain may vary in size from tens of cubic metres to tens of thousands of cubic metres in the Cairns area. The large debris flow fans in the Redlynch area have volumes of millions of cubic metres, but these are built up over probably tens of thousands of years. The 1951 Ellis Beach debris flows had a total volume of over 300 000 m3 [For comparison, The tragedy at Thredbo was only about 400 m3].The following map was taken from the report.  It shows landslides known to have occurred in the vicinity of False Cape, which are believed to date from the 1878 event. The "Fc" on the map corresponds to a legend item of "Massive core debris flow deposit with irregular lobate surface and numerous boulders greater than 1 m" [This is the highest landslide category].  A photo of a boulder 200 m out from the shore is also provided as according to the map, this boulder may have been transported to this location by the event indicated on the map.  The landslide that would have crossed areas that are within the envelope of proposed development.   Would Mr Lamprell like to provide his expert reports on this issue, so that we can rest assured that the issue of debris flows has been properly investigated.  Please use this link to go to the False Cape forum and press the post button to enter a comment .

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