Southern Australia IMOS field surveys started in 2008 and have been refined from the dense set of transects typically undertaken until 2013 (Figure 1) below to the 3 transect lines for 2014/2015 shown in Figure 2 below (These three transects cover inflows from the GAB including dense water outflows of winter) as well as along and cross shelf transects to monitor for outflows from Spencer Gulf and upwelling from Kangaroo Island. During these field surveys, CTD cast profiling is undertaken along with mooring deployments at which sampling of biogeochemical tracers was undertaken. Southern Australia IMOS enjoys a record of not loosing any moorings in over 50 field cruises.
Southern Australia IMOS has serviced three mooring sites continuously which are:
- National Reference Station Kangaroo Island (NRSKAI) - 2008-current
- South Australian Mooring Coffin Bay (SAM5CB) - 2009-12, 2014-current
- South Australian Mooring Spencer Gulf (SAM8SG) - 2009-current
The field program associated with these moorings for 2014/2015 is shown in Figure 2 below.
In addition to the above Coffin Bay, Spencer Gulf and Kangarioo Island sites, a further five sites have had moorings deployed over the years indicated in the following:
- South Australian Mooring Cabbage Patch (SAM2CP) - 2008-10
- South Australian Mooring Canyon (SAM4CY) - 2009-10
- South Australian Mooring Investigator Straight (SAM6IS) - 2009
- South Australian Mooring Deep Slope (SAM7DS) - 2011-14
- South Australian Mooring Mid Slope (SAM3MS) - 2011-13
More precise mooring dates are listed below. The locations of all moorings are shown in Figure 1 above and listed in Table 1 below.
For the 2011-2013 period, five moorings were deployed (Figure 1 above) with the addition of SAM3MS on the 200 m isobath and SAM7DS on the 500 m isobath. Data from both moorings showed currents at these depths to be dominated by weak mesoscale eddies and due to difficulties of servicing (large waves and unprotected vessel shelter), both were discontinued.
Following the reduction in resources for the 2015/2017 period, a corresponding reduction was made to the field program as shown in Figure 3 below: the CTD casts to the Coffin Bay mooring SAM5CB have been discontinued.
Table 1. Mooring locations and nominal depths
|Mooring site||Longitude °E||Latitude °S||Nominal Depth (m)||Status|
More details of mooring deployment dates can be downloaded as an excel sheet and are colour coded as:
Mooring Recovered and data available.
Mooring Deployed but not yet retrieved.
Mooring not deployed
SARDI’s research vessel R.V. Ngerin is generally used for deployments and retrievals and hosts a winch for CTD and Niskin bottle samples as well as a sea crane (HIAB) for mooring deployments and retrievals. The vessel has a crew of four and can accommodate six scientific staff.