Data from: Rapid retreat of Berry Glacier, West Antarctica linked to seawater intrusions revealed by radar interferometry
Data files
Sep 13, 2025 version files 4.79 MB
Abstract
We employ a time series of ERS-1/2, ALOS-2 PALSAR, Sentinel-1, and COSMO-SkyMed differential synthetic-aperture radar interferometry data from 1996 to 2021 to document the short-term and long-term migrations of the grounding line (GL) of Berry Glacier, West Antarctica, a major tributary of Getz Ice Shelf that controls 10 % of its ice discharge. We detect a short-term migration of 18.0 ± 0.9 km with changes in oceanic tide, which translates into a major revision of the bed topography to reveal a subglacial valley 1,300 m deeper than previously known. The migration is not in phase with the tide and oscillates between three states controlled by spatial variations in bed topography. Seawater intrusions alternate with extrusions and trapping of seawater. During 1996-2021, the GL retreated more than 18 km, or 0.7 km/yr, ice thickness decreased by 11 ± 1 m/yr, the glacier sped up by 64 ± 5%, and the mass loss totalled 131 ± 23 Gt. We attribute the retreat to enhanced heat flux from warm Circumpolar Deep Water (CDW) via favorable bathymetric channels and km-sized seawater intrusions beneath the glacier. Interaction with a complex bed topography, however, limited the efficiency of the ocean at carving a new cavity and forcing a more rapid retreat.
This dataset contains drainage basin utilized to compute surface mass balance; flux gates for ice discharge calculation of three time periods; grounding line (GL) shapefiles mapped based on corresponding double-difference interferograms covering Berry Glacier over period 1996-2021; grounding zone (GZ) shapefile made up with the most retreated and the least retreated GLs; profile shapefile along GL migration direction used to calculate bed, surface, thickness, ice speed, surface height change, and furthermore GZ width from hydrostatic equilibrium; GL density map; pinning points derived from the interferograms; and analysis about GL migration vs. tidal height and changes in surface height/flow speed/mass balance.
Description of the Data and File Structure
All the shapefiles and maps can be opened in QGIS or other similar GIS softwares. Recommended coordinate reference system to open the data is EPSG:3031 - WGS 84 / Antarctic Polar Stereographic.
Table of Contents
- drainage basin
- flux gates
- GL shapefiles
- GZ shapefiles
- line density
- pinning points
- profile shapefile
- GL analysis, tidal heights, speed & surface height.xlsx
File/Folder Details
Details for: drainage basin
- Description: a folder containing a drainage basin shapefile of Berry Glacier showing the region where surface mass balance is computed.
- Format(s): .shp
- Size(s): 3.38 KB
Details for: flux gates
- Description: a folder containing three flux gate shapefiles of Berry Glacier showing the cross section positions where ice discharge is calculated. Flux gate A-B is for the year 1996, flux gate C-D is for the time period 2006-2011, and flux gate E-F is for the time period 2012-2022.
- Format(s): .shp
- Size(s): 2.59 KB
Details for: GL shapefiles
- Description: a folder containing two subfolders: "GL individuals" and "GL collection". The first subfolder respectively includes 2 GLs of ERS-1/2, 5 GLs of ALOS PALSAR, 57 GLs of Sentinel-1, and 24 GLs of COSMO-SkyMed covering Berry Glacier for the years 1996, 2008-2009, and 2019-2021, which are mapped based on the correspond high-quality double-difference interferograms. The second subfolder contains GL collections for the each years. The double-difference interferograms are generated with 3 or 4 radar images from ERS-1/2, ALOS PALSAR, Sentinel-1, and COSMO-SkyMed satellites. As phase quality in the interferograms is not uniform across the scene, GL mapping is not always complete in the 88 interferograms.
- Format(s): .shp
- Size(s): 11.2 MB
Details for: GZ shapefiles
- Description: a folder containing the GZ shapefiles of Berry Glacier showing annual GL migration boundaries during 2019-2021 as well as three-year total boundary.
- Format(s): .shp
- Size(s): 38.0 KB
Details for: line density
- Description: a folder containing the line density map generated with the GLs. The line density interpolation calculates a density measure of linear features which is obtained in a circular neighborhood within each raster cell. It shows the frequency of GL positions between 2019 and 2021.
- Format(s): .tif
- Size(s): 4.36 MB
Details for: pinning points
- Description: a folder containing a pinning point shapefile in the GZ of Berry Glacier showing the locations where the glacier is partially grounding and the direction of water flushing in/out is changed. It's dervied based on 15 interferograms.
- Format(s): .shp
- Size(s): 12.0 KB
Details for: profile shapefiles
- Description: a folder containing a profile indicating the location where the bed, surface and thickness are calculated from BedMachine Antarctica v3.7, the ice bottoms are computed from WorldView and ICESat-2 DEMs, and GZ width of hydrostatic equilibrium is calculated. It's along the direction of the GL migration.
- Format(s): .shp
- Size(s): 1.60 KB
Details for: GL analysis, tidal heights, speed & surface height.xlsx
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Description: a file containing information about acquisition time and number of fringes of the double-difference interferograms of Sentinel-1 and COSMO-SkyMed; GL migration along Berry Glacier; tidal height at the acquisition time of the double-difference interferograms, which is calculated from CATS2008 tide model with inverse barometer effect (IBE) correction computed from ERA5; comparision between differential displacement in DInSAR and differential tide height with IBE, which indicates the DInSAR method and the tide model both are reliable; bed from BedMachine v3.7, ice bottoms computed from WorldView and ICESat-2 DEMs, and OIB ice bottoms along the profiles; speed and surface height along the profiles from 1996 to 2022; and discharge, surface mass balance, and total mass balance in time serier over 1996-2022. Cells marked with "n/a" are because of lacking of information. Below is a detailed description of each sheet and its variables.
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Format(s): .xlsx
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Size(s): 370 KB
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Sheet 1: GL analysis & tidal heights
This sheet contains records of grounding line and associated tidal heights.
Variables:
Datetime1, Datetime2, Datetime3, Datetime4 – Time stamps (UTC) for consecutive satellite acquisitions. Format: YYYY-MM-DD hh:mm:ss.
mid-time – Midpoint time between acquisition pairs (UTC).
positive error (days) – Positive uncertainty of the temporal separation.
negative error (days) – Negative uncertainty of the temporal separation.
number of fringes – Count of interferometric fringes detected.
differential displacement (cm) in DInSAR – Line-of-sight differential displacement between image pairs (centimeters).
differential tide height (cm) – Modeled differential tide height from CATS2008 tide model bewteen image pairs (centimeters).
GL migration_Berry (m) – Grounding line migration compared with 1996 grounding line position for Berry Glacier (meters).
positive error (m) – Positive uncertainty of the grounding line migration.
negative error (m) – Negative uncertainty of the grounding line migration.
tide1–tide4 (cm) – Modeled tide height from CATS2008 tide model at four timestamps.
pressure1–pressure4 (Pa) – Modeled atmospheric pressure values at four timestamps.
IBE1–IBE4 (cm) at 50/100 km – Inverse barometer effect (IBE) correction values (centimeters) at 50/100 km from grounding line.
tide1+IBE1 – tide4+IBE4 (cm) – Combined ocean tide height plus IBE correction (centimeters).
maximum tide height (cm) with IBE at 50/100 km – Maximum corrected tide height (centimeters).
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Sheet 2: bed & surface elevations
This sheet provides cross-section profiles of glacier geometry along grounding line migration transects.
Variables:
profile along the direction of GL migration – Profile identifier.
distance (m) – Along-flow distance from a reference point (meters).
bed (m) – Bed elevation relative to sea level (meters; negative values indicate below sea level).
REMA surface (m) – Surface elevation from REMA DEM (meters).
WorldView ice bottom (m) – Ice base elevation derived from WorldView stereo data (meters).
ICESat-2 ice bottom (m) – Ice base elevation derived from ICESat-2 altimetry (meters).
ATM surface (m) – Surface elevation from NASA Airborne Topographic Mapper (ATM) lidar (meters).
DEM ice bottom (m) – Ice base elevation from DEM (meters).
OIB ice bottom (m) – Ice bottom elevation from Operation IceBridge radar (meters).
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Sheet 3: surface height
This sheet contains time series of ice surface elevation profiles along a grounding line migration transect.
Variables:
distance along the direction of GL migration (m) – Along-flow distance (meters).
Year YYYY_surface height (m) – Surface elevation (meters) at given year from remote sensing data. Each column corresponds to a specific year (e.g., 1996, 1997, …, 2022).
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Sheet 4: speed
This sheet contains glacier surface velocity profiles along a grounding line migration transect.
Variables:
distance along the direction of GL migration (m) – Along-flow distance (meters).
Year YYYY_speed (m/yr) – Surface velocity (meters per year) for each year (1996, 2006, 2008, 2009, 2010, 2011, 2012, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021, 2022).
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Sheet 5: mass balance
This sheet provides annual glacier mass balance estimates, combining discharge and surface mass balance data.
Variables:
Year – Calendar year of the measurement.
δDischarge (Gt) – Change in ice discharge relative to baseline (gigatonnes).
SMB (Gt) – Surface mass balance in gigatonnes per year.
δSMB (Gt) – Change in SMB relative to baseline (gigatonnes).
δM (Gt) – Net mass balance anomaly (gigatonnes).
cumulative δDischarge (Gt) – Cumulative discharge anomaly relative to baseline (gigatonnes).
cumulative δSMB (Gt) – Cumulative SMB anomaly relative to baseline (gigatonnes).
cumulative δM (Gt) – Cumulative net mass balance anomaly (gigatonnes).
SMB 1979–2004 (Gt) – Long-term mean surface mass balance over 1979–2004 (gigatonnes).