Information
Comments
The last of the 12 CASO CTD casts along the SR3 transect was completed at 2000 hrs last night. This was the 130th CTD for the voyage, with 44 samples taken along the CASO transects and a further 86 at the CEAMARC sites. The SR3 transect was first occupied in 1991 by Aurora Australis; the present voyage will be the 7th re-occupation of the line. The time series of measurements along SR3 is the longest and most continuous set of observations available to document changes in the deep and bottom waters of the Southern Ocean. The CASO CTD stations east of the Mertz Glacier taken earlier in the voyage showed clearly that the bottom water flowing west from the Ross Sea is significantly fresher than observed in the 1990s. The SR3 line of stations just completed will show whether the bottom water produced in the Mertz Polynya region is also changing. The CTD samples taken at the CEAMARC sites will provide key information on physical conditions in the overlying waters that may help explain the distribution and abundance patterns seen in the communities of bottom-living animals. With an average depth of about 1300m for all 130 sites, a total of about 170kms of CTD wire has been paid out from the winch and wound back in again during the course of the voyage. Regards, Martin and Sarah.
Map
A map showing Australia and Antarctica. The map shows the journey of one voyage that has occured in the season, with each route highlighted in a distinct colour.