Date (Creation)

2024-02-06

Date (Publication)

2024-02-06

Date (Revision)

2024-10-22

Code

omrader_farlige_bolger

Purpose

Waves and their importance for navigation were the subject of much attention in the 70-80s. Investigations showed that waves under unfortunate circumstances could be the cause of capsizing accidents and other major damage to ships. When planning a voyage or other activity, one must be aware of the areas with dangerous waves and obtain additional information about updated weather and wave conditions from available services.

Status

Completed

Point of contact

Organisation name	Individual name	Electronic mail address	Role
Norwegian Mapping Authority	Siri Reimers	reisir@kartverket.no	Publisher
Norwegian Mapping Authority	Siri Reimers	reisir@kartverket.no	Owner

Maintenance and update frequency

Not planned

Nasjonal inndeling i geografiske initiativ og SDI-er

• Nautisk informasjon

Nasjonal tematisk inndeling (DOK-kategori)

• Kyst og fiskeri

• Samferdsel

• Samfunnssikkerhet

• Vær og klima

Place

• Norway's coastel areas

• Northsea, norwegian areas

• Norwegian Sea

• Skagerrak

• Barents Sea

Theme

• Caution

• Waves

• Warning

• dangerous waves

• Barentswatch

• wave warning

Spatial scope

• National

Specific usage

The dataset can be used for planning, illustrations, research and analysis. It can be useful in decision-making tools used in connection with navigation planning, in development, planning and management work, and in support services for navigation, meteorology and wave warnings.

User contact info

Organisation name	Individual name	Electronic mail address	Role
			Owner

Use limitation

None

Access constraints

Other restrictions

Other constraints

Åpne data

Use constraints

Other restrictions

Other constraints

Creative Commons BY 4.0 (CC BY 4.0)

Other constraints

None

Classification

Unclassified

Spatial representation type

Vector

Denominator

1:5 000 000

Language

Norwegian

Unique resource identifier

EPSG:25832

Unique resource identifier

EPSG:25833

Unique resource identifier

EPSG:25835

Unique resource identifier

EPSG:3035

Unique resource identifier

EPSG:4248

Unique resource identifier

EPSG:4258

Distribution format

Name	Version
FGDB	10.0
GeoJSON
GML	3.2.1
PostGIS	12
SOSI	4.5
FGDB
GeoJSON
GML
PostGIS
SOSI

Units of distribution

fylkesvis, kommunevis, landsfiler

OnLine resource

Protocol	Linkage	Name
GEONORGE:DOWNLOAD	https://nedlasting.test.geonorge.no/api/capabilities/

Hierarchy level

Dataset

Statement

The chapter Waves and weather on the Norwegian coast with a description of hazardous areas was first published in Den norske los vol. 1 in the edition published in 1981 and is mainly taken from the research project Ships at sea from 1978 -1980. The purpose of the project was to improve the safety of smaller ships in heavy seas. The maps were produced by Kjeldsen & Myrhaug at the Norwegian Institute of Marine Technology Research in 1978 for the report. The initiative for the project Skip i sjøgang was at the Norwegian Ship Research Institute (now MARINTEK) with department engineer Terje Nedrelid as project manager. It was funded by the Norwegian Maritime Authority, the Norwegian Fisheries Research Council and the Norwegian Research Council for Science and Technology.

The project showed by mathematical calculations that these areas concentrate wave energy due to their local topography and current conditions. Under certain weather conditions, the waves will be steeper inside these areas than further out in deep water. As an important part of the work to map typically dangerous areas along the coast, an extensive survey was conducted among pilots and fishermen where they were asked to describe the wave conditions in the places they believed to have unusually rough seas. Responses were received from people living along the entire coast, and 19 dangerous areas were referred.

The list was expanded in the following years with 5 new areas. The report specified that the list is not exhaustive and that these are not the only areas along our coast where such phenomena occur. But these are in areas with heavy traffic and many of them are in the middle of the shipping lane. The areas marked in maps with textual descriptions are essentially the source for the further modernized maps in further publication of volume 1 up to 2018.

Words and phrases in the dataset:

- Refraction is a physical phenomenon in which a wave movement changes direction in the transition from one medium to another. The term is used in nautical sciences/meteorology to refer to wave formations.

-Breakers occur mostly in shallow water. When a wave touches the bottom, the energy will be pushed upwards. We see it on the beach, where the burns rise and roll in from seemingly calm seas outside. However, the phenomenon can also occur in deep water by merging several waves to create an extra high and steep wave with a high energy content. The water is accelerated to about 3 g and the top shoots forward and strikes down into the valley in front. The rushing flood closes an air pocket inside it, creating large and dangerous shock pressures. Such a burn is very large and can even lead to the breakdown of large ships.

The digitization has been done by georeferencing the maps using modern coastal contour and digitizing the areas on screen with the maps as backgrounds. The positional accuracy must be considered approximate. But given the fuzzy nature of the areas, in terms of source and purpose, it is considered sufficient to convey that particular care should be taken in areas with dangerous waves.

The accompanying text for the 24 areas is entered as attributes.

Metadata

File identifier

1cdf2c9d-f9b5-4a66-8563-62c7600db245 XML

Metadata language

Norwegian

Hierarchy level

Dataset

Date stamp

2025-05-31

Metadata standard name

ISO19115

Metadata standard version

2003

Metadata author

Organisation name	Individual name	Electronic mail address	Role
Norwegian Mapping Authority	Siri Reimers	reisir@kartverket.no	Point of contact

Other language

Language	Character encoding
English	UTF8