This indicator is no longer maintained, and is considered OBSOLETE.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: Polar Bird Dates in ice: 23 Nov 2000 - 19 Dec 2000 Observers: Mel Fitzpatrick, Ian Allison Summary of voyage track: 23/11 Ice edge at approx. 63S, 111E 23-27/11 Ice edge to Casey fly off 28/11 - 17/12 Ship stuck in ice, drifting slowly westward 18-19/12 Steamed north to ice edge at approx. 64S, 104E 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: 29 Mar 1993 - 30 Mar 1993 Observers: Tony Worby, Vicky Lytle, Rob Massom, Paul Scott, Kelvin Michael Summary of voyage track: Short transect south of the ice edge at approx 65S, along approx 140E. This voyage was cut short due to a medical emergency only one day after entering the pack ice. 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: Polar Sea Dates in ice: 19 Dec 1998 - 01 Jan 1999 Observers: Tony Worby Summary of voyage track: 19/12 Ice edge at approx. 63S, 140E 19-21/12 From ice edge to coast 22-28/12 Steamed west to approx 177W 28/12 - 1/1 Steamed south into the Ross Sea 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: Kapitan Khlebnikov Dates in ice: 10 Nov 1995 - 22 Nov 1995 Observers: Steve Ackley Summary of voyage track: 10/11 At ice edge at approx. 60S, 44W 10-12/11 Heading east 13-17/11 Heading predominantly south along approx 10-15W 19-22/11 Heading north along approx same track as route south 22/11 Ice edge at approx. 60S, 27W 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: 16 Oct 1990 - 10 Nov 1990 Observers: Rob Kiernan, Martin Higham, Smart, Smyth Summary of voyage track: 16/10 Ice edge at 61d07mS, 115d19mE 16-18/10 Vessel steamed from ice edge to Casey 20-30/10 Vessel steamed from Casey to Mawson 1-4/11 Vessel steamed from Mawson to Davis 8-10/11 Vessel steamed from Davis to ice edge at 61d10'S, 83d37mE 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: 20 Oct 1993 - 01 Nov 1993 Observers: Martin Higham, Rob Kiernan, David N, D Murphy Summary of voyage track: 20/10 Ice edge at approx 60S, 114E 20-28/10 Vessel steamed westward to Mawson 30/10 - 2/11 Vessel steamed from Mawson to Davis No sea ice observations were made after 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: 20 Mar 1999 - 26 Mar 1999 Observers: Petra Heil Summary of voyage track: 20/3 Ice edge at approx. 65S, 65E 20-21/3 Ice edge to Mawson 24-26/3 Mawson 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: 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