Title
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Trough geomorphic feature layer |
Date
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2013-06-05 |
Date type
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Creation: Date identifies when the resource was brought into existence
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Date
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2014-02-14 |
Date type
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Publication: Date identifies when the resource was issued
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Edition
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Version 1 |
Code
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1e0c14c6-4719-42e8-a57f-d6c04cd02518 |
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Presentation form
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Digital map: Map represented in raster or vector form
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Abstract
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The trough geomorphic feature layer represents the spatial extent of the troughs of the worlds oceans based on interpretation
of the SRTM30 plus v7 global bathymetry model. The layer is one of the 25 layers that make up the global seafloor geomorphic
features map (Harris et.al. 2014). The IHO (IHO, 2008) definition of a trough is “a long depression of the sea floor characteristically
flat bottomed and steep sided and normally shallower than a trench”. In this study we found that troughs are also commonly
open at one end (i.e. not defined by closed bathymetric contours) and their broad, flat floors may exhibit a continuous gradient
along a thalweg. Troughs may originate from glacial erosion processes or have formed through tectonic processes. In this study,
glacial troughs incised into the shelf are a separate category; here we include all troughs not of a glacial origin, typically
superimposed on the slope and/or abyssal base layers. Trenches that have been infilled with sediment may evolve into troughs,
as appears to have occurred in troughs adjacent to North and South America, for example. Slumping on the sides of some troughs
has formed a bridge across the trough, thereby dividing it into two separate sections (see “bridges” below). In this study
all troughs were digitised by hand based on the interpretation of 100 m bathymetric contours.
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Purpose
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The trough geomorphic feature layer represents the spatial extent of the troughs of the worlds oceans based on interpretation
of the SRTM30 plus v7 global bathymetry model. The layer is one of the 25 layers that make up the global seafloor geomorphic
features map (Harris et.al. 2014). The global seafloor geomorphic features map is intended to support ocean management including
feature inventories, spatial planning and biodiversity conservation.
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Credit
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The global seafloor geomorphic features map has been produced through a collaboration between Geoscience Australia, GRID-Arendal
and Conservation International. Reference: Harris et. al. (2014) Geomorphology of the oceans.Marine Geology (in Press)
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Maintenance and update frequency
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Irregular: Data is updated in intervals that are uneven in duration
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Descriptive keywords
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Geology (theme). |
Descriptive keywords
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global (place). |
Descriptive keywords
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seafloor, geomorphic features, habitats (theme). |
Descriptive keywords
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Downloadable Data . |
Use limitation
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The global seafloor geomorphic feature map is available for download from bluehabitats.org |
Access constraints
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Other restrictions: Limitation not listed
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Other constraints
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no limitations |
Spatial representation type
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Vector: Vector data is used to represent geographic data
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Character set
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UTF8: 8-bit variable size UCS Transfer Format, based on ISO/IEC 10646
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Topic category code
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Oceans |
Environment description
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Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; ESRI ArcGIS 10.0.4.4000 |
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