The Antarctic Iceberg Tracking Database
1978 & 1992-present (Brigham Young University)
Jeff Budge and David G. Long
Last database update: 1 Jan 2021 (for current positions click here)
Tracking A68A: update
(Iceberg Tracks from 1999-2010)
Using data from all available satellite scatterometer instruments, along with
measurements from the National Ice Center (NIC), we have produced
a consolidated iceberg tracking database. The BYU database includes icebergs
identified in enhanced resolution scatterometer backscatter images during
July-Sept. 1978 (from Seasat), July 1996-June 1997 (from NSCAT),
1992-2001 (from ERS-1/2), June 1999-November 2009 (from QuikSCAT), 2008-present (from ASCAT),
2012-2014 (from OSCAT), 2017-present (OSCAT2).
Images were obtained from the Scatterometer
Climate Record Pathfinder (SCP) project.
Data sets from multiple different spaceborne scatterometer instruments
are used to track icebergs. For each data set, resolution
enhancement is performed by BYU's Scatterometer Image reconstruction
(SIR) and/or SIR Filtering (SIRF) algorithms. The scatterometer
instruments used in this study are the Seasat-A Satellite
Scatterometer (SASS), the European Space Agency's Remote Sensing
Satellite 1(2) (ERS-1/-2), the NASA Scatterometer (NSCAT), the
QuikSCAT/SeaWinds scatterometer (QSCAT), the MetOp-A and MetOp-B
Advanced Scatterometer (ASCAT) sensors, and the Indian Space Research
Organization's Oceansat-2 scatterometer. The Seasat-A
scatterometer (SASS) was a dual-polarization Ku-band (14.6 GHz)
scatterometer that operated from July to Sept. 1978. Using the SIRF
algorithm, Antarctic images are generated every 12-48 days (a
longer time is required for SASS compared to other instruments due to
the sampling characteristics of the nominally 50 km backscatter
measurements). The ERS-1/2 spacecraft carried a C-band (5.3 GHz)
active microwave instrument (AMI). The scatterometer mode
provides nominally 50 km resolution data. Using SIR, Antarctic
images are produced every 6 days. The ERS-1/2 scatterometers
operated from Jan. 1992 to Jan. 2001. The NSCAT scatterometer is
a Ku-band Doppler radar similar to SASS, but with dual-side
measurement capability and a dense 25 km resolution sampling.
Using SIRF, Antarctic images were produced every 3 days. The
NSCAT mission lasted from Sept. 1996 to June 1997. QuikSCAT was
launched as a ``quick recovery'' mission to help fill the gap created
by loss of NSCAT due a satellite failure. This scatterometer
allows daily images of Antarctica to be created. QuikSCAT
operated from July 1999 to November 2009. ASCAT-A was launched in
October of 2006 and is currently operational. Since then two other
ASCATs have been launched. The ASCAT senors operate at C-Band
(5.255 GHz) at vertical polarization only. The SIRF algorithm
applied to ASCAT (Standard BYU ASCAT Land/Ice
Products) generates images from 1 and 2 days of data over
Antarctica. Iceberg tracks for ASCAT have only been done back to the
beginning of the ASCAT data. This provides an overlap of two data sets
(QuikSCAT and ASCAT) for a few years (October 2006 to November
2009). The Oceansat-2 scatterometer (OSCAT-1) dataset begins August 2011
and continues through the end of March 2014. Its antenna geometry and
frequency are similar to that of QuikSCAT.
A follow-on OSCAT mission (OSCAT-2 on ScatSat)
began in Nov. 2016, and is currently be used for iceberg tracking.
The initial position for each iceberg is located based on either
(1) a position reported by the National Ice Center (NIC)'s web page
or (2) by the sighting of a moving iceberg in a time series of
scatterometer images. From an initial point, the iceberg
is tracked in the scatterometer image time series forward and backward
in time to major calving or breakup events. Gaps in the
position track result from long time/space spacing in NIC reports,
missing scatterometer data and from the
occasional loss ofcontrast between the iceberg and surrounding area
during summer months. Where possible interpolation is done to give an estimate
of its position during those times. For each image, a lat/lon position is
reported for each iceberg, with mostly daily position updates.
In the consolidated database, lengths of the major and minor axes of
each iceberg are given.
"Named" icebergs are those whose name (which starts with a, b, c, or d)
is assigned by the NIC. Other icebergs were also observed in scatterometer data. These are the "unnamed" icebergs and stored in files that begin with s, e, uor k, depending on the time period.
Iceberg positions are reported in a separate CSV file for each
iceberg. The file name is the same as that of the iceberg. For example
the file "b27.csv" contains the position track information for B27 from ASCAT.
A few lines from the b27.csv file are shown below:
Latitude and longitude are specified in decimal degrees
with positive North and East, respectively. The day is specified
as YYYYDDD, with the day given as a three digit day of the year. Size are dimensions in km.
A separate database containing more derivative measurements and statistics is also given
in the links below. This database contains a single latitude and longitude point for each day,
as well as an estimate of size (in sq km) and rotation velocity.
The iceberg database and statistical database can be obtained via the links shown
ASCAT-A/B/C and OSCAT-2 are now the primary sensors and positions are derived from a combination of all sensors. While the real-time positions are updated weekly or more often, the full database files referred to on this page are only updated a few times per year.
If you become aware of a large (>5 km) Antarctic iceberg not contained in the database during the time period of our sensors, please inform us of its position and the time of observation. We can then use historical data to determine its origin and fate and add it to the tracking database.
As of 12 July 2017, the top Antarctic icebergs of all time ranked by size are:
|Iceberg ||Area (sq km)|
|B15 || 11000|
|A20 || 7284|
|A24 || 6863|
|C19 || 6368|
|A23 || 5883|
|A68 || 5800|
|B10 || 5689|
|A38 || 5603|
|A22 || 5212|
|B09 || 5096|
CONSOLIDATED DATABASE FILES (format and contents)
The consolidated BYU/NIC iceberg database is described in the paper J.S. Budge and D.G. Long, "A Comprehensive Database for Antarctic Iceberg Tracking Using Scatterometer Data," IEEE Journal of Selected Topics in Applied Earth Observations, Vol. 11, No. 2, doi:10.1109/JSTARS.2017.2784186, 2017.
The individual database files are stored as comma separated values (.csv) that can be read by common spreadsheet programs. Matlab functions to read and plot the database files are available: consolplot.m and statsplot.m
Within each zip file are one file per iceberg, with the name of the iceberg as the name of the file. Each of these .csv files is arranged with a single row header, showing what data each column contains. The names should be self explanatory.
For the stats dtabase there is a field for the date, mean latitude and longitude of all sensor positions given for that date, an estimate of the size (sq km) and rotation velocity of that berg, and a mask indicating its surroundings type. For reference, Mask Values
|0 ||Near Land or no data|
|1 ||Sea Ice |
|2 ||Open Ocean |
|3 ||No Data |
The 'flags' column indicates the senor(s) used to compute the reported
mean latitudes and longitudes. It is a decimal number corresponding to the sensors used to create the single track, as well as a single bit to show if the measurement is interpolated. Each sensor is one 4 bite nibble. The nibbles are arranged as follows: (from lsb)
|Nibble ||Sensor |
|1 ||SASS |
|2 ||ERS |
|3 ||NSCAT |
|4 ||SeaWinds |
|5 ||QuikSCAT |
|6 ||OSCAT |
|7 ||ASCAT |
|8 ||NIC (multiple sensors)|
OLD DATABASE FILES**
**note: the old version of the BYU iceberg database is no longer being updated after 2016.
ASCAT portion of the database in a gzipped tar file from the SCP web site: icebergDatabase_ascat.tar.gz
QSCAT portion of the database in a gzipped tar file from the SCP web site: icebergDatabase_qscat.tar.gz
OSCAT portion of the database in a gzipped tar file from the SCP web site: icebergDatabase_oscat.tar.gz
All other portions (SASS, ERS-1/2, NSCAT) in a gzipped tar file from the SCP web site: icebergDatabase_other.tar.gz
J.S. Budge and D.G. Long, "A comprehensive database for Antarctic iceberg tracking using scatterometer data," IEEE Journal of Selected Topics in Applied Earth Observations, Vol. 11, No. 2, doi:10.1109/JSTARS.2017.2784186, 2017.
(847 kB PDF*)
K.M. Stuart and D.G. Long, "Tracking large tabular icebergs using the SeaWinds Ku-band microwave scatterometer", Deep-Sea Research Part II,
doi:10.1016/j.dsr2.2010.11.004, Vol. 58, pp. 1285-1300, 2011.
(1.6 MB PDF)
D.G. Long, J. Ballantyne, and C. Bertoia, "Is the Number of Icebergs Really Increasing?" EOS, Transactions of the American Geophysical Union, Vol. 83, No. 42, pp 469 & 474, 15 Oct. 2002.
(620 kB PDF)
K.M. Stuart and D.G. Long, "Iceberg Size and Orientation Estimation using SeaWinds", Cold Regions Science and Technology, doi:10.1016/j.coldregions.2011.07.006, 2011. (1.7MB PDF)
**An older report further describing this multidecadal database of Antarctic
icebergs observed with scatterometer data is available in pdf format from
the SCP web site at IcebergReport.
Animations of the daily movement of selected individual icebergs can be found here. Note that many icebergs do not move for extended periods of time.
Support from both NASA and NSF is acknowledged.
Last Revised: 24 Jan 2021
For further information contact:
Dr. David G. Long
Professor, Electrical and Computer Eng. Dept. https://www.ee.byu.edu/
Brigham Young University
450 Engineering Building
Provo, Utah 84602
Microwave Earth Remote Sensing (MERS) Lab: https://www.mers.byu.edu/
Scatterometer Climate Record Pathfinder: https://www.scp.byu.edu/