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Ice shelf - ocean interaction in the cavity beneath the Amery Ice Shelf
Entry ID: ASAC_1164

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Summary
Abstract: ---- Public Summary from Project ----
Most of the snow falling on inland Antarctica drains via large ice streams and floating ice shelves to the sea where it lost by iceberg calving or as melt beneath the shelves. Ocean interaction beneath the shelves is complicated, and regions of basal refreezing as well as melt occur. These processes are important not only because they are a major component of the Antarctic mass budget, but because they also modify the characteristics of the ocean, influencing the formation of Antarctic Bottom Water which plays a major role in the global ocean circulation. The processes are sensitive to climate change, and shifts in ocean temperature or circulation near Antarctica could lead to the disappearance of all Antarctic ice shelves.

The Amery
Ice Shelf is the major embayed shelf in East Antarctica, and the subject of considerable previous ANARE investigation. Ocean interaction processes occurring beneath the shelf are only poorly understood, and this project will directly measure water characteristics and circulation in the cavity underneath the ice shelf, and the rates of melt and freezing on the bottom of the shelf. These measurements will be made through a number of access holes melted through the shelf. The project is closely linked with other projects investigating the circulation and interactions in the open ocean to the north of the shelf, and studies of the ice shelf flow and mass budget.

There will be child records for each of the following data sets:
AM01 and AM01 b boreholes
* CTD profiles through water column
* CTD annual records at selected depths
* Ocean current profiles through water column
* Temperature measurements through ice shelf and across ice-water interface
* Small ice core samples
* 0.5 m sea floor sediment core
* Video footage of borehole walls (including marine ice) and sea floor benthos
* GPS records of surface tidal motion
* Video

AM02 borehole
* CTD profiles through water column
* CTD annual records at selected depths
* Borehole diameter caliper profiles
* Temperature measurements through ice shelf and across ice-water interface
* 1.5 m sea floor sediment core
* GPS records (surface elevation, ice motion)

AM03 borehole
* Aquadopp current meter data
* Brancker thermistor data
* Caliper data
* FSI-CTD profile data
* Drilling parameters data
* Seabird MicroCAT CTD moorings at three depths in ocean cavity beneath the shelf
* Video

AM04 borehole
* Aquadopp current meter data
* Brancker thermistor data
* Caliper data
* FSI-CTD profile data
* Drilling parameters data
* Seabird MicroCAT CTD moorings at three depths in ocean cavity beneath the shelf
* Video

AM05 borehole
* Aquadopp current meter data
* Caliper data
* FSI-CTD profile data
* Drilling parameters data
* Seabird MicroCAT CTD moorings in ocean cavity beneath the shelf

AM06 borehole
* Aquadopp current meter data
* Caliper data
* FSI-CTD profile data
* Drilling parameters data
* Seabird MicroCAT CTD moorings in ocean cavity beneath the shelf


Taken from the 2008-2009 Progress Report:
Progress Against Objectives:
The work undertaken in the past 12 months has continued to relate chiefly to the first of our objectives - "quantify the characteristics and circulation of ocean water in the cavity beneath the Amery Ice Shelf". Data from the AMISOR project have provided the first record of a seasonal cycle of ice shelf-ocean interaction. After recovering the 2008 data we now have near-continuous oceanographic data from beneath the Amery at 3 different depths for 6, 6, 3, and 3 years from 4 different sites. Note that the instruments at AM01 and AM02 (6 annual cycles of data each) are no longer recording due to expiration of the onboard batteries (3-5 years expected life cycle). This allows us to investigate the "real" 3-D, seasonally varying, circulation and melt/freezing cycle beneath an ice shelf - rather than the steady state, simplified "2-D ice pump circulation" that has mostly been assumed previously.

As much as 80% of the continental ice that flows into the Amery Ice Shelf from the Lambert Glacier basin is lost as basal melt melt beneath the southern part of the shelf, but a considerable amount of ice is also frozen onto the base in the north-western part of the shelf. These processes of melt and refreezing are due to a pattern of water circulation beneath the ice shelf which is driven by sea ice formation outside the front of the shelf. Our multi-year data from 4 sites beneath the Amery ice shelf show that there is a very strong seasonal cycle in the characteristics of the ocean water beneath the shelf, and strong interseasonal variability in this. The seasonal cycle is driven mostly by the seasonal cycle of sea ice formation and decay in Prydz Bay, and interseasonal variations are due to differences in the general ocean circulation, and in particular the upwelling of Circumpolar Deep Water onto the continental shelf in Prydz Bay. The melt and freeze processes beneath the ice shelf, also themselves modify the water characteristics.

Taken from the 2009-2010 Progress Report:
The AMISOR project drilled two new 600 m deep boreholes on the Amery Ice Shelf in 2009-10: the first on the marine ice flowline to enhance understanding of the re-freezing process beneath the shelf; and the second in a region of known interest with respect to circulation patterns in the ocean cavity below the shelf. Instrument deployments at both sites should provide valuable annual cycle data over the next 4-5 years.

Related URL
Link: GET DATA
Description: Download point for the data


Link: VIEW PROJECT HOME PAGE
Description: Public information for ASAC project 1164


Link: VIEW RELATED INFORMATION
Description: Citation reference for this metadata record and dataset


This description is a member of a collection. Click to see members of this collection.

Geographic Coverage
 N: -69.19 S: -70.56  E: 72.64  W: 70.37
 Min Depth: 100 M  Max Depth: 1350 M

Data Set Citation
Dataset Originator/Creator: Allison, I. and Craven, M.
Dataset Title: Ice shelf - ocean interaction in the cavity beneath the Amery Ice Shelf
Dataset Series Name: CAASM Metadata
Dataset Publisher: Australian Antarctic Data Centre
Online Resource: https://data.aad.gov.au/aadc/metadata/metadata_redirect.cfm?md=/AMD...


Temporal Coverage
Start Date: 2000-01-01


Location Keywords
OCEAN > SOUTHERN OCEAN
CONTINENT > ANTARCTICA
GEOGRAPHIC REGION > POLAR


Science Keywords
CRYOSPHERE >SNOW/ICE >ICE DEPTH/THICKNESS    [Definition]
CRYOSPHERE >GLACIERS/ICE SHEETS >ICE SHEETS    [Definition]
CRYOSPHERE >SNOW/ICE >SNOW/ICE TEMPERATURE    [Definition]
OCEANS >BATHYMETRY/SEAFLOOR TOPOGRAPHY >WATER DEPTH    [Definition]
OCEANS >MARINE SEDIMENTS >SEDIMENT COMPOSITION    [Definition]
OCEANS >MARINE SEDIMENTS >SEDIMENTATION    [Definition]
OCEANS >MARINE SEDIMENTS >STRATIGRAPHIC SEQUENCE    [Definition]
OCEANS >OCEAN CIRCULATION >OCEAN CURRENTS    [Definition]
OCEANS >OCEAN TEMPERATURE >POTENTIAL TEMPERATURE    [Definition]
OCEANS >OCEAN TEMPERATURE >THERMOCLINE    [Definition]
OCEANS >OCEAN TEMPERATURE >WATER TEMPERATURE    [Definition]
OCEANS >SALINITY/DENSITY >CONDUCTIVITY    [Definition]
OCEANS >SALINITY/DENSITY >SALINITY    [Definition]
CRYOSPHERE >SNOW/ICE >SNOW/ICE CHEMISTRY    [Definition]


ISO Topic Category
GEOSCIENTIFIC INFORMATION
INLAND WATERS
OCEANS


Platform
GROUND-BASED OBSERVATIONS    [Information]
FIELD INVESTIGATION    [Information]


Quality
See Readme files in the download files of the child metadata records for details of data quality and equipment down-time.

Note - depths provided in spatial coverage are referenced back to sea level. The minimum depth asl refers to the height of the ice surface.


Access Constraints
Check the child records for availability of data.

A summary excel file is available for download from the URL given below.


Use Constraints
This data set conforms to the PICCCBY Attribution License
(http://creativecommons.org/licenses/by/3.0/).

Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_1164 when using these data.


Keywords
AMERY ICE SHELF
AMISOR
BATHYMETRY
HOT WATER DRILL
ICE CORES
ICE THICKNESS
SALINITY
SEDIMENTS
TEMPERATURE
VELOCITY


Data Set Progress
IN WORK


Originating Center
Australian Antarctic Division


Data Center
Australian Antarctic Data Centre, Australia    [Information]
Data Center URL: http://data.aad.gov.au

Data Center Personnel
Name: DATA OFFICER AADC
Phone: +61 3 6232 3244
Fax: +61 3 6232 3351
Email: metadata at aad.gov.au
Contact Address:
Australian Antarctic Division
203 Channel Highway
City: Kingston
Province or State: Tasmania
Postal Code: 7050
Country: Australia



Distribution
Distribution_Media: HTTP
Distribution_Size: 11 kb
Distribution_Format: excel
Fees: free


Personnel
IAN ALLISON
Role: INVESTIGATOR
Role: TECHNICAL CONTACT
Phone: +61 3 6226 7648
Fax: +61 3 6226 7650
Email: ian.allison at aad.gov.au
Contact Address:
Australian Antarctic Division
203 Channel Highway
City: Kingston
Province or State: Tasmania
Postal Code: 7050
Country: Australia


MIKE CRAVEN
Role: TECHNICAL CONTACT
Role: DIF AUTHOR
Phone: +61 3 6226 7876
Fax: +61 3 6226 6902
Email: m.craven at utas.edu.au
Contact Address:
203 Channel Highway
Australian Antarctic Division
City: Kingston
Province or State: Tasmania
Postal Code: 7050
Country: Australia


Publications/References
Craven M., Elcheikh A., Brand R., Jones N. (2002), Hot water drilling on the Amery Ice Shelf - the AMISOR project., Memoirs of National Institute of Polar Research. Special Issue., 56, 217-225

Fricker H.A., Popov S., Allison I., Young N.W. (2001), Distribution of marine ice beneath the Amery Ice Shelf., Geophysical Research Letters, 28, 11, 2241-2244

Jacka T.H., and the ISMASS Committee (2004), Recommendations for the collection and synthesis of Antarctic Ice Sheet mass balance data., Global and Planetary Change, 42, 1-15

Craven M., Allison I., Brand R., Elcheikh A., Hunter J., Hener M., Donoghue S. (2004), Initial borehole results from the Amery Ice Shelf hot-water drilling project., Annals of Glaciology, 39, 531-539

Young N.W., Hyland G. (2002), Velocity and strain rates derived from InSAR analysis over the Amery Ice Shelf, East Antarctica., Annals of Glaciology, 34, 228-234

Fricker H.A., Young N.W., Allison I., Coleman R. (2002), Iceberg calving from the Amery Ice Shelf, East Antarctica., Annals of Glaciology, 34, 241-246

Craven M., Carsey F., Nicol S. (2006), Ice krill under the Amery Ice Shelf, East Antarctica., Antarctic Science, 18, 1, 81-82

Craven M., Carsey F., Behar A., Matthews J., Brand R., Elcheikh A., Hall S., Treverrow A. (2005), Borehole imagery of meteoric and marine ice layers in the Amery Ice Shelf, East Antarctica., Journal of Glaciology, 51, 172, 75-84

Roberts D., Craven M., Cai M., Allison I., Nash G. (2006), Protists in the marine ice of the Amery Ice Shelf, East Antarctica., Polar Biology, doi:doi 10.1007/s003000-0006-0169-7

Riddle M.J., Craven M., Goldsworthy P.M., Carsey F. (2007), A diverse benthic assemblage 100 km from open water under the Amery Ice Shelf, Antarctica, Paleoceanography, 22, PA1204, doi:doi:10.1029/2006PA001327

Post A.L., Hemer M.A., O'Brien P.E., Roberts D., Craven M. (2007), History of benthic colonisation beneath the Amery Ice Shelf, East Antarctica, Marine Ecology Progress Series, 344, doi:doi: 10.3354/meps06966

Hemer M.A., Post A.L., O'Brien P.E., Craven M., Truswell E.M., Roberts D., Harris P.T. (2007), Sedimentological signatures of the sub-Amery Ice Shelf circulation, Antarctic Science, doi:DOI: 10.1017/S0954 102007000697

Hemer M.A., Harris P.T. (2003), Sediment core from beneath the Amery Ice Shelf, East Antarctica, suggests mid-Holocene ice-shelf retreat, Geology, 31, 2, 127-130

Maraldi C., Galton-Fenzi B., Lyard F., Testut L., Coleman R. (2007), Barotrophic tides of the Southern Indian Ocean and the Amery Ice Shelf cavity, Geophysical Research Letters, 34, L18602, doi:doi:10.1029/2007GL030900

Cai M.-H., Li Y.-S., Allison I., Curran M.A.J. (2006), Chemical and biological properties of marine ice from the Amery Ice Shelf, East Antarctica., Abstracts of the SCAR Open Science Conference, 0256/313, Hobart, 12-14 July 2006

Post A.L., Hemer M.A., Roberts D., O'Brien P.E., Craven M. (2006), Life beneath the ice: A history of benthic colonisation beneath the Amery Ice Shelf, Antarctica., Abstracts of the SCAR Open Science Conference, 0153/112, Hobart, 12-14 July 2006

Galton-Fenzi B.K., Tassell H., McMahon K., Coleman R., Hunter J., Pedro J. (2006), Observing the ice pump under the Amery Ice Shelf, Abstracts of the SCAR Open Science Conference, 0412/313, Hobart, 12-14 July 2006

Carsey F.D., Behar A., Engelhardt H., Craven M., Vogel S., Christoffersen P (2004), Study of Ice Sheet Basal Processes With Visible Light Images Acquired from a Borehole Probe, AGU Fall Meeting, 85, 47, Session: Uses of Photography in Cryospheric Studies, 13-17 December 2004
C42A-08

Allison I., Hunter J., Craven M. (2005), Spatial and seasonal variability of ice-ocean interaction beneath the Amery Ice Shelf, Conference Program and Abstract Book: Dynamic Planet 2005, 79, 82, Cairns, Australia, August 22-26, 2005

Allison I. (2003), Climate interactions in the marine cryosphere., Abstract Volume, XXIII General Assembly of the International Union of Geodesy and Geophysics, B.63, Sapporo, Japan. July 2003
JSM10/07P/B23-001

Allison I., Fricker H., Craven M., Young N. (2003), The AMISOR project: Amery Ice Shelf dynamics and ice-ocean interaction., Abstract Volume, XXIII General Assembly of the International Union of Geodesy and Geophysics, B.64, Sapporo, Japan. July 2003
JSM10/7P/B23-007

Rapley C., Bell R.E., Allison I., and 12 others (2004), A new phase of polar exploration and understanding: the International Polar Year - 2007-2008, SCAR Open Science Conference "Antarctica and the Southern Ocean in the Global Systems", Bremen, Germany, 25-31 July 2004

Craven M., Brand R., Elcheikh A., Hall S., Treverrow A, Matthews J (2004), AMISOR-4 2003-04 AM01b Summer Field Report "Run away, run away..."

Craven M. (2003), On the Shoulders of Giants - Part 3: The AMISOR Project 2001-02., Aurora, 22, 3, 14-17

Hunter J., Hemer M., Craven M. (2004), Modelling the Circulation Under the Amery Ice Shelf., Proceedings of the 17th International FRISP Workshop, Cambridge, U.K., 15, 1-6, FRISP Report

Leffanue H., Craven M. (2004), Circulation and water masses from current meter and T/S measurements at the Amery Ice Shelf. Smedsrud L., 15, 73-79, FRISP Report

Allison I. (2003), The AMISOR project: ice shelf dynamics and ice-ocean interaction of the Amery Ice Shelf., 16th International FRISP Workshop in Bergen, 14, 9, Geophysical Institute, University of Bergen, Norway

Allison I. (2003), The AMISOR project: ice shelf dynamics and ice-ocean interaction of the Amery Ice Shelf., 16th International FRISP Workshop in Bergen, 14, 9, Geophysical Institute, University of Bergen, Norway,FRISP Report

Treverrow A., Warner R.C., Craven M., Budd W.F. (2007), Crystallography of the Amery Ice Shelf, Marine and Meteoric Ice Observations Antarctic Climate and Ecosystems CRC Symposium, Hobart, 2007

Craven M., Rasch D., Brand R., Drinkell A., Donoghue S., Pedro J. (2006), Borehole imagery within and beneath the Amery Ice Shelf, Abstracts of the SCAR Open Science Conference, Hobart, 12-14 July 2006
0196/313 (Poster)

Craven M. (2004), AMISOR Trilogy: The diesel and the dog., Australian Antarctic Magazine, 6, 18-19

Allison I. (2001), Peephole through the ice: the AMISOR project., Australian Antarctic Magazine, 20-21

Creation and Review Dates
DIF Creation Date: 2000-08-09
Last DIF Revision Date: 2016-01-27



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