Positions and dimensions of the A68 icebergs between September 2020 and April 2021

This dataset contains daily positions of the A68 family of giant icebergs during their drift through the Scotia Sea and South Atlantic between 2020-09-01 and 2021-04-16. Positions were obtained using optical imagery collected by MODIS Aqua and Terra satellites. For the parent iceberg A68A, the evolving dimensions (long and short axis length, area) are also provided, based on Synthetic Aperture Radar imagery acquired by Copernicus Sentinel 1A and 1B satellites. This data can be used to plot the trajectories of the A68 icebergs during their drift in the Scotia Sea and near South Georgia.

This data was collected during an MSc/MRes student project at the Department of Geography, University of Sheffield, in 2020/21. The work was not supported by any funding or research grants.

Alternate title: Polar Data Centre (PDC) record GB/NERC/BAS/PDC/01732

Date (Publication): 2023-04-21

Citation identifier: http://www.antarctica.ac.uk/dms/metadata.php?id= / GB/NERC/BAS/PDC/01732

Point of contact

Organisation name	Individual name	Electronic mail address	Role
British Antarctic Survey		pdc@bas.ac.uk	Custodian
NERC EDS UK Polar Data Centre	Smith, R., & Bigg, G.	pdc@bas.ac.uk	Originator

Maintenance and update frequency: Unknown

Keywords

NDGO0001

NERC OAI Harvesting

NERC_DDC

GCMD Parameter Valids

EARTH SCIENCE > Cryosphere > Glaciers/Ice Sheets > Icebergs
EARTH SCIENCE > Cryosphere > Sea Ice > Icebergs
EARTH SCIENCE > Oceans > Sea Ice > Icebergs

BAS Free-text keywords

A68
Icebergs
South Georgia
satellite observations
trajectories

Use limitation: Data supplied under Open Government Licence v3.0 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/.

Access constraints: Other restrictions

Other constraints: Data supplied under Open Government Licence v3.0 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/.

Language: English

Topic category

Oceans

Begin date: 2020-09-01

End date: 2021-04-16

Reference system identifier: OGP / urn:ogc:def:crs:EPSG::4326

Distribution format

Distributor contact

Organisation name	Individual name	Electronic mail address	Role
Polar Data Centre - British Antarctic Survey		pdc@bas.ac.uk	Distributor

OnLine resource

Protocol	Linkage	Name
http	https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=d56d9e3f-80d2-4076-9e70-24f662c0e362	GET DATA

Hierarchy level: Dataset

Domain consistency

Measure identification: INSPIRE / Conformity_001

Conformance result

Title: INSPIRE Data Specification on unknown theme Guidelines

Date

Explanation: See the referenced specification

Pass: No

Statement: Where cloud cover precluded accurate iceberg positioning for a single day, the coordinates were interpolated based on the positions of the preceding and subsequent days, assuming constant speed. This occurred for less than 10 percent of the positions noted for each iceberg, and the error introduced is expected to be minimal, owing to the very large size of the tracked icebergs, and known currents, throughout the study period.

For the parent iceberg A68A, cloud cover prevented continuous daily tracking in the two final weeks of its lifetime, in April 2021. Owing to the relatively small size of this final remaining iceberg at this time, and the large (3-4 days) gaps in observations, the missing positions were not interpolated for this final period and instead are left unknown. This results in ''snapshot'' positions in the final two week period, until the iceberg''s final melt on 2021-04-16.

Wherever data is missing (due either to lack of interpolation as described, or more commonly due to an iceberg''s non-existence on that day), a value of 9999 is provided for ease of filtering.