This indicator is no longer maintained, and is considered OBSOLETE. INDICATOR DEFINITION Regular measurements of the thickness of the fast ice, and of the snow cover that forms on it, are made through drilled holes at several sites near both Mawson and Davis. TYPE OF INDICATOR There are three types of indicators used in this report: 1.Describes the CONDITION of important elements of a system; 2.Show the extent of the major PRESSURES exerted on a system; 3.Determine RESPONSES to either condition or changes in the condition of a system. This indicator is one of: CONDITION RATIONALE FOR INDICATOR SELECTION Each season around the end of March, the ocean surface around Antarctica freezes to form sea ice. Close to the coast in some regions (e.g. near Mawson and Davis stations) this ice remains fastened to the land throughout the winter and is called fast ice. The thickness and growth rate of fast ice are determined purely by energy exchanges at the air-ice and ice-water interfaces. This contrasts with moving pack ice where deformational processes of rafting and ridging also determine the ice thickness. The maximum thickness that the fast ice reaches, and the date on which it reaches that maximum, represent an integration of the atmospheric and oceanic conditions. Changes in ice thickness represent changes in either oceanic or atmospheric heat transfer. Thicker fast ice reflects either a decrease in air temperature or decreasing oceanic heat flux. These effects can be extrapolated to encompass large-scale ocean-atmosphere processes and potentially, global climate change. DESIGN AND STRATEGY FOR INDICATOR MONITORING PROGRAM Spatial Scale: At sites near Australian Antarctic continental stations: Davis; Mawson. Frequency: at least weekly, reported annually Measurement Technique: Tape measurements through freshly drilled 5 cm diameter holes in the ice at marked sites. RESEARCH ISSUES To more effectively analyse the changes in Antarctic fast ice a detailed long-term dataset of sea ice conditions needs to be established. This would provide a baseline for future comparisons and contribute important data for climate modelling and aid the detection of changes that may occur due to climate or environmental change. LINKS TO OTHER INDICATORS SOE Indicator 1 - Monthly mean air temperatures at Australian Antarctic stations SOE Indicator 40 - Average sea surface temperatures in latitude bands 40-50oS, 50-60oS, 60oS-continent SOE Indicator 41 - Average sea surface salinity in latitude bands: 40-50oS, 50-60oS, 60oS-continent SOE Indicator 42 - Antarctic sea ice extent and concentration The fast ice data are also available as a direct download via the url given below. The data are in word documents, and are divided up by year and site (there are three sites (a,b,c) at each station). Snow thickness data have also been included. A pdf document detailing how the observations are collected is also available for download.

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Australia Vessel: Icebird Dates in ice: 4 Nov 1989 - 2 Dec 1989 Observers: Rob Kiernan, Martin Higham, others Summary of voyage track: 4/11 Ice edge at 58d22mS, 78dE 4-10/11 Steamed SW to approx 60dE 10-23/11 Vessel stuck in pack ice near 60dE 24-28/11 Vessel steamed eastward to near 77dE (Davis station) 30/11-2/12 Vessel steamed north to ice edge at 61d33mS, 82dE The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Australia Vessel: Aurora Australis Dates in ice: 27 Oct 1994 - 23 Nov 1994 Observers: Andrew Watkins, Kelvin Michael, Michael Wall Summary of voyage track: 27/10 Ice edge at approx. 61S, 111E 27-29/10 Vessel steamed from ice edge to Casey 30/10-4/11 Off Casey for flying operations 5-11/11 Vessel steamed from Casey to Davis 15-23/11 Vessel steamed east from Davis to 100E, then north to the ice edge at approx. 62S The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Australia Vessel: Aurora Australis Dates in ice: 02 Oct 1997 - 26 Oct 1997 Observers: Michael Wall Summary of voyage track: 2/10 Ice edge at approx. 62S, 114E 2-5/10 Vessel steamed from ice edge to Casey 8-18/10 Vessel steamed from Casey to 66E 18-22/10 Vessel stopped in ice (rudder damage) 22-26/10 Vessel steamed east to Davis The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Australia Vessel: Aurora Australis Dates in ice: 21 Jul 1995 - 26 Aug 1995 (HIHO HIH0 experiment) Observers: Tony Worby, Ian Allison, Vicky Lytle, Rob Massom, Petra Heil Summary of voyage track: Scientific voyage focussed on the area near 64S, 140E. Three laps of a 60 x 60 nmile study area were completed with E-W and N-S transects through the study region to deploy and recover instruments. The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Australia Vessel: Icebird Dates in ice: 28 Oct 1988 - 23 Nov 1988 Observers: Ian Allison, Steve Warren, Rich Brandt Summary of voyage track: 28/10 Ice edge at 62d37mS, 112d04mE 28-30/10 Steamed toward Casey (110E) 1-6/11 Steamed west to approx 77E 6-12/11 Steamed north-south along approx. 77E 13-18/11 Steamed west to Mawson ice edge (61E) 20-23/11 Steamed north to ice edge at 60d52mS, 66d04mE The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Australia Vessel: Aurora Australis Dates in ice: 08 Sep 1994 - 11 Oct 1994 Observers: Tony Worby, Ian Allison, Ross Edwards, Jason Phillips Summary of voyage track: 8/9 Ice edge at approx 60S, 150E 8-18/9 Vessel steamed along approx. 62S to 75E 19-24/9 Vessel steamed south along 75E 25-26/9 Vessel steamed into Davis 28-29/9 Vessel steaming north from Davis 30/9-7/10 Vessel beset in heavy ice 8-11/10 Vessel steamed north to ice edge at approx. 60S, 86E The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Australia Vessel: Aurora Australis Dates in ice: 22 Jul 1999 - 31 Aug 1999 Observers: Tony Worby, Ian Allison, Vicky Lytle, Rob Massom, Anton Rada, Matt Paget, Andrew Roberts Summary of voyage track: 22/7 Ice edge at approx. 62S, 143E 22/7 - 31/8 Complicated voyage track in and around the Mertz Glacier polynya CTD loops around the polynya region: Loop 1: 5-7/8 Loop 2: 12-14/8 Loop 3: 20-22/8 The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Australia Vessel: Aurora Australis Dates in ice: 22 Apr 1995 - 27 Apr 1995 Observers: Arne Sorenson Summary of voyage track: From Casey to the ice edge. The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: United States Vessel: Endurance Dates in ice: 17 Jan 1998 - 13 Feb 1998 Observers: Steve Ackley, Elizabeth Hunke Summary of voyage track: 17/1 Ice edge at approx. 57S, 31W 17-20/1 South along approx 30W 21/1-2/2 West in toward Antarctic peninsula 3-13/2 East along ice shelf to approx. 8W 13/3 North to ice edge at approx. 68S, 12W The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS