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Waterlines delimiting the edge of the Hunga Tonga - Hunga Ha'apai island between April 2017 and April 2022 (NERC Grant NE/X002454/1)

Waterlines have been extracted to delimit the edge of the Hunga Tonga - Hunga Ha'apai island between April 2017 and April 2022. Waterline is defined as the instantaneous land - water boundary at the time of the imaging process. Waterlines have been generated by BGS - Earth Observation team through a thresholding-based classification based on Sentinel-2 multispectral imagery and developed on Google Earth Engine. Specifically, the thresholding has been applied to the Normalized Difference Water Index (NDWI) has been derived as a basis to discriminate between the land and sea based on their spectral characteristics. Changes in waterlines over volcanic islands can provide key information to understand volcanic processes. For more info on the methodology, see Novellino et al. (2020) https://doi.org/10.3390/app10020536

Simple

Date (Creation)
2022-11-24
Citation identifier
http://data.bgs.ac.uk/id/dataHolding/13608017
Point of contact
Organisation name Individual name Electronic mail address Role

British Geological Survey

Enquiries

enquiries@bgs.ac.uk

Distributor

British Geological Survey

Enquiries

enquiries@bgs.ac.uk

Originator

British Geological Survey

Enquiries

not available

Distributor

British Geological Survey

Enquiries

not available

Point of contact
Maintenance and update frequency
notApplicable

GEMET - INSPIRE themes, version 1.0

  • Geology

BGS Thesaurus of Geosciences

  • NGDC Deposited Data

  • Imagery

  • Volcanic activity

  • Satellite imagery

dataCentre
  • NGDC Deposited Data
Keywords
  • NERC_DDC

Access constraints
Other restrictions
Other constraints
licenceOGL
Other constraints
Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]"
Use constraints
Other restrictions
Other constraints

The copyright of materials derived from the British Geological Survey's work is vested in the Natural Environment Research Council [NERC]. No part of this work may be reproduced or transmitted in any form or by any means, or stored in a retrieval system of any nature, without the prior permission of the copyright holder, via the BGS Intellectual Property Rights Manager. Use by customers of information provided by the BGS, is at the customer's own risk. In view of the disparate sources of information at BGS's disposal, including such material donated to BGS, that BGS accepts in good faith as being accurate, the Natural Environment Research Council (NERC) gives no warranty, expressed or implied, as to the quality or accuracy of the information supplied, or to the information's suitability for any use. NERC/BGS accepts no liability whatever in respect of loss, damage, injury or other occurence however caused.

Other constraints

Available under the Open Government Licence subject to the following acknowledgement accompanying the reproduced NERC materials "Contains NERC materials ©NERC [year]"

Spatial representation type
Vector
Language
English
Topic category
  • Geoscientific information
Geographic identifier
TO

ISO 3166_1 alpha-2 2009 revision

Geographic identifier
TON

ISO 3166_1 alpha-3 2009 revision

Geographic identifier
TONGA [id=936000]

British Geological Survey Gazetteer: Geographical hierarchy from Geosaurus 1979 creation

N
S
E
W
thumbnail




Begin date
2017-04-01
End date
2022-04-30
Unique resource identifier
WGS 84 / UTM zone 1S (EPSG::32701)
Distribution format
Name Version

Shapefile

Distributor contact
Organisation name Individual name Electronic mail address Role

British Geological Survey

Enquiries

enquiries@bgs.ac.uk

Distributor
Distributor contact
Organisation name Individual name Electronic mail address Role

British Geological Survey

Enquiries

not available

Distributor
OnLine resource
Protocol Linkage Name
https://webapps.bgs.ac.uk/services/ngdc/accessions/index.html#item176958

Data

Hierarchy level
Dataset
Other

dataset

Conformance result

Title

INSPIRE Implementing rules laying down technical arrangements for the interoperability and harmonisation of Geology

Date (Publication)
2011
Explanation

See the referenced specification

Pass
No

Conformance result

Title

Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services

Date (Publication)
2010-12-08
Explanation

See http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:323:0011:0102:EN:PDF

Pass
No
Statement

The Sentinel-2 images used as input to the workflow comprised Level-1C image products. These are composed of 100 × 100 km2 tiles that are ortho-images in cartographic geometry according to the UTM/WGS84 projection, with radiometric corrections applied to convert each pixel value from the digital number (DN) to Top of Atmosphere (TOA) reflectance. We use median values within a month period, pending availability of the data due to cloud coverage. The remaining images have been thresholded based on the Normalized Difference Water Index (NDWI) is used to as a basis to discriminate between the land and sea based on their spectral characteristics. Methodology is described in detail in Novellino et al., (2021) at https://doi.org/10.3390/app10020536

Metadata

File identifier
f287da43-4913-77ff-e053-0937940a0d43 XML
Metadata language
English
Hierarchy level
Dataset
Date stamp
2025-05-08
Metadata standard name
UK GEMINI
Metadata standard version

2.3

Metadata author
Organisation name Individual name Electronic mail address Role

British Geological Survey

enquiries@bgs.ac.uk

Point of contact
Dataset URI

http://data.bgs.ac.uk/id/dataHolding/13608017

 
 

Overviews

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Spatial extent

thumbnail

Keywords

NGDC Deposited Data


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