Nautical Chart
INT-905
"Northern Weddell Sea"


Page content:

Administration
Regional definitions
Chart specifications
Correlated meetings
Cooperating hydrographic services

Chart production
Raw data editing
Calculation of grids
Calculation of soundings
Contouring and morphologic modelling
Quality assessment
Final chart production
Updates

Products
Electronic Nautical Chart (ENC)
Paper chart
Metadata description
Corresponding project
 Chart content
Hydroacoustic data
Soundings
Contour lines / depth areas
Contour lines from AWI-BCWS
Contour lines from other INT charts
Land elevation from ADD5
Coast lines
Feature names
Terrestrial feature names
Names of the seas
Undersea feature names
Names of research stations
Sea ice extension
Currents
Magnetic variations - Isogons
Boundaries of other INT charts
Navigational lights
Underwater obstructions
Caution areas
IALA Maritime Buoyage System
Administration area

Administration

The paper chart and the corresponding ENC will be produced in a joint project by the German Federal Maritime and Hydrographic Agency (BSH) as national HO, and the Alfred Wegener Institute for Polar and Marine Research (AWI), which holds much of the bathymetric source data for this region. Since 1983 the research vessel Polarstern is visiting the Weddell Sea and a huge dataset of swath file bathymetry was recorded. Furthermore a scientific bathymetric chart of the Weddell Sea was produced at AWI (AWI-BCWS) and experiences of its processing and data validation will be incorporated in the INT‑905 chart.
Data evaluation and processing will be carried out at AWI. The cartographic work and ENC production was initially planned to be finished at BSH until summer 2011.

Regional definitions
RegionM - ANTARCTIC WATERS
CoordinatorInternational Hydrographic Organization (IHO)
Commission CommitteeHydrographic Commission on Antarctica (HCA)
Contact PersonIng. en Chef Michel HUET -

INT chart boundaries in HCA region M    

Chart specifications are documented in IHO publication S-11, Part B, Region M

INT chart number905
National chart number (DE)1700
TitleNorthern Weddell Sea
Title in national languageWeddellsee, nörlicher Teil
1st editionPlanned for 2011
Producer nationGermany - Bundesamt für Seeschiffahrt und Hydrographie (BSH)
ContactSylvia.Spohn@bsh.de
Ralf.Krocker@awi.de
Bounding coordinates (W / E / S / N)-59:00 / -11:00 / -71:00 / -59:10
Scale1 : 2,000,000
Projection (EPSG)WGS 84 / World Mercator (3395)
Latitude of true scale66° 00' S
Vertical datum (EPSG)Mean Sea Level (5100)
Navigational purpose (by means of IHO S-44)1 - Overview
Matching scale ranges200 NM / 96 NM for 1:3,000,000 to 1:1,500,000


Correlated meetings

10th Meeting of Hydrographic Commission of Antarctica - Cambridge, United Kingdom, 20-22 September 2010
During this meeting the previous name of INT‑905 chart was changed from "South Sandwich Islands" to "Northern Weddell Sea".
(Meeting documents)

3rd Arctic/Antarctic Seafloor Mapping Meeting - Stockholm, Sweden, 3-5 May 2011
(Link to GEBCO meeting notes)
(Link to Stockholms universitet meeting notes)


Cooperating hydrographic services

The production of INT‑905 chart is supported from other hydrographic services, which provided INT charts within INT 905 region.
Adjacent maps will be used for adjustments especially of contour lines within overlapping areas.

ARGServicio de Hidrografia Naval
BRAHidrografia e Navegação
CHLServicio Hidrográfico y Oceanográfio
GBRThe United Kingdom Hydrographic Office
NORNorwegian Mapping authority




Chart content

Hydroacoustic data

The providers of hydroacoustic data for INT-905 chart are registered in alphabetical order:
Alfred-Wegener-Institute for Polar and Marine Research (AWI)profile previewMultibeam
NGDC - Geophysical Data System (GEODAS)profile previewSinglebeam
The United Kingdom Hydrographic Office (UKHO)profile previewSinglebeam

The rawdata will be used to generate soundings. In ENC they are represented by S-57 acronym SOUNDG.



Contour lines / depth areas

Contour lines are generated for depths of 100, 200, 300, 400, 500, 1000, 2000, 3000, 4000, 5000, 6000 and 7000 meter. In the ENC, contours with depth of 300 and 400 meter will not be adopted.
Contour lines of depth=0 (coastline) is provided separately - see below
S-57 acronym for contour lines is DEPCNT, the acronym for the depth areas between the contour lines is DEPARE. Upper and lower limit of depth area are defined in attributes DRVAL1 and DRVAL2.
Depth areas between contours 0 and 200 meter will be coloured in dark blue. This depth area will also be defined as "Caution Area" (see below). Depth areas between contours 200 and 500 meter will be colored in light blue.

Contour lines from AWI-BCWS
Because of the large gaps between profiles, the hydroacoustic data are insufficient for contour generation. Therefore additional information must be taken into account for detailed modelling. The countour lines of the Bathymetric Chart of the Weddell Sea (AWI-BCWS) were taken to support this task. These contours are also implemented in the GEBCO Digital Atlas (GDA). The scale of AWI-BCWS is 1:1,000,000 and matches the requirements for INT‑905 production.
The AWI BCWS is published in PANGAEA network with DOI: 10.1594/PANGAEA.708081. See also: 10013/epic.13351.

Contour lines from other INT charts
Adjacent INT charts of same scale are overlapping and corresponding contour lines are used for inter chart adjustments, if necessary.
Contour lines of larger scale INT charts within INT‑905 chart area will be generalized and implemented, if no hydroacoustic data are available for that region. See scheme of charts within INT‑905 region.

purpose 1
(overview)		 purpose 2
(general)		 purpose 3
(coastal)
INT-904; (NO1A5500); NOR
INT-906; GBR
INT-907; (GB104907); GBR
INT-9170; ARGINT-9150; BRA
INT-9153; (GB372220); GBR / ARG
INT-9154; (GB372210); GBR / ARG
INT-9155; (CL3MA800); CHL

Following pictures show contour lines of neighbouring charts INT‑904 and INT‑907 (highlighted in red) compared to the contours of INT‑905:
vs. INT‑907 (1), vs. INT‑907 (2), vs. INT‑907 (3), vs. INT‑904 (1), vs. INT‑904 (2) and vs. INT‑904 (3).

Land elevation
Land elevation data were taken from Antarctic Digital Database Version 5 (ADD) providing contours in two different scales: 1:1,000,000 and most detailed. Both datasets were downloaded and generalized as needed. Unfortunately the more appropriate dataset of scale 1:1,000,000 is showing implausible contours as can be seen in linked picture showing Elephant Island and Clarence Island. This picture also shows a positional offset of ADD5 contours compared to the coast lines of Clarence Island, which are provided by NGDC. The position of NGDC World Vector Shoreline dataset was granted a higher trustworthiness and ADD5 contour lines of Clarence Island were shifted to fit that coast lines.
Contour lines are adopted for heights of 200, 500, 1000 and 1500 meter. If one of these depth contours are not provided for an area, it was interpolated between neighbouring contours.
Validation tool of Caris HPD Source Editor was detecting contour lines of 1000 and 1500 meter to be erroneous, because they do not fit template ###.# .
S-57 acronym for land elevation is LNDELV.

Coast lines
The coastlines are taken from dataset World Vector Shoreline, provided from NGDC.
ENC S-57 acronym for coast lines is COALNE. Attribute CATCOA defining the category of coast line was not specified.
Coast lines have been generalized manually. Afterwards the lines have been generalized using Caris Base Editor applying Peuker&Douglas Algorithm with deviation value of 100 meter.
Due to the small scale of the chart and the large depths with its corresponding uncertainties, the vertical datum has not been converted into the charts vertical datum 'Mean Sea Level'.
Coast lines are the base of depth areas with upper limit of 0 meter (DRVAL1=0), land areas, land regions and sea areas.



Feature names

There are several naming gazetteers listing feature names in Antarctica which are specialized for different types of features. Nevertheless many features are registered in several gazetteers and sometimes with slightly different names or other attributes. Antarctic region is defined by its northern boundary of 60° S. Northern boundary of INT‑905 is 50° 10' S so some features to be charted are not listed in the Antarctic gazetteers. In ENC the feature names are assigned to attribute OBJNAM and NATNAM. To OBJNAM the international common names are assigned, to NATNAM the corresponding names in German transliteration if exists. In the paper chart all English names for islands, undersea feature names and names of research stations are displayed. German names are assigned to the names of the seas.
The CGA gazetteer is providing the features position as a point, SCUFN as point or line and the ASD as textual description. In ENC the features geometries are defined to be areas. So the extension of some features needed to be redefined.

Terrestrial feature names
S-57 acronym for the geographic representation of land areas is LNDARE. The acronym for their labeling is LNDRGN. Attribute CATLND defining the category of land region was not specified. Geometries by means of boundaries of land areas and land regions were defined snapping/referencing coast line geometry (COALNE).
Small scaled islands are defined as point geometry.
Except Cook Island all islands are also registered in the APC gazetteer.

ASD IDCGA IDIsland (→ OBJNAM)
5.32366Andersson Island
4.112570Aspland Island
5.53589 Île de l'Astrolabe
5.321760Bransfield Island
4.722713Clarence Island
3.180---Cook Island
4.303006Coronation Island
5.103239d'Urville Island
5.103960Dundee Island
7.164017Eagle Island
4.994163Elephant Island
4.1085301Gibbs Island
7.277051James Ross Island
5.107202Joinville Island
4.1277527King George Island
4.208190Laurie Island
4.12710143Nelson Island
4.2011544Powell Island
4.13012135Ridley Island
7.3513059Seymour Island
4.3413266Signy Island
7.3813585Snow Hill Island
3.180---Thule Island
7.1115361Vega Ön


ASD IDCGA IDRegion (→ OBJNAM)
5.2419Antarctic Peninsula
7.178618Cape Longing
5.5212355Cape Roquemaurel
5.4614958Trinity Peninsula




The names of the seas
are registered in IHO publication S-23 fourth edition final draft (August 2002).
S-57 acronym for the names of the seas is SEAARE, attributes CATSEA are not set. The boundaries of SEAARE are defined snapping/referencing coast line geometry, if they coincide.
In ENC the german names are also adopted in attribute NATNAM.

S-23 IDASD IDCGA IDName of the sea (→ OBJNAM)(→ NATNAM)
10.144.711762Bransfield StraitBransfield Straße
4.3 / 10.133.53862Drake PassageDrakepassage
10.27733Kong Håkon VII. SeaKong Håkon VII. Meer
4.23.5-Scotia SeaScotiameer
4-South Atlantic OceanSüdatlantischer Ozean
10-Southern OceanSüdpolarmeer
10.17.115833Weddell SeaWeddellsee


Undersea Feature Names
Following table lists all CGA IDs, SCUFN IDs, names and related S-57 category of B-8 (version July 2010) features within INT‑905 chart area. Due to database updates the links in column SCUFN-ID may temporarily not be available.
S-57 acronym for undersea feature names is SEAARE. The generic terms as categorised in IHO publication B-6 are enumerated in S-57 feature attribute CATSEA. In ENC all features geometries are defined to be areas adjusting the point and line geometries given by B-8.

CGA IDSCUFN IDUndersea Feature Name (→ OBJNAM)CATSEA
418157Antarctic Canyon11
639241Aurora Canyon11
952284Barsukov Seamount16
1938421Bruce Ridge15
3583778Deutschland Canyon11
3900828Drygalski Canyon11
-851East Scotia Ridge15
4256910Endurance Canyon11
4260912Endurance Ridge15
4411950Explora Escarpment30
-1215Guevara Seamounts40
63221311Hespérides Trough22
77731649Kosminskaya Fracture Zone32
81441721Larsen Basin7
173781730Lazarev Seamount16
84391758Ligeti Ridge15
86371782Loper Seachannel44
103942235North Weddell Ridge15
-2305Ona Basin7
154982311Orca Seamount16
114252466Polarstern Canyon11
115402488Powell Basin7
126712701San Martin Canyon11
167672811Shackleton Fracture Zone32
137312927South Orkney Trough22
137382928South Sandwich Fracture Zone32
-2929South Sandwich Trench6
137412931South Shetland Trough22
137392930South Scotia Ridge15
152233220Uruguay Canyon11
158293318Weddell Abyssal Plain18
158453319Wegener Canyon11
18301 / 173813368Wordie Seamount / Wordie Caldera16
155303272Vinogradov Fracture Zone32
163623394Yelcho Canyon11




Research stations
are the most prominent destinations of shipping within INT‑905 region. Within this region 15 stations are located.
They are registered in Composite Gazetteer of Antarctica (CGA-ID) and in the Admiralty Sailing Directions - Antarctic Pilot (NP9), 7th edition 2009 (ASD-ID). They are also registered by COMNAP in xml file Antarctic facilities.
CGA object class of "Man-made features" is 14. S-57 acronym for research stations is BUISGL.

ASD IDCGA IDBase name (→ OBJNAM)Geographic position
4.171554Artigas Base 2, URY-62.1845, -58.9038
4.171-Bellingshausen Station, RUS-62.1983, -58.9640
4.156-Commandante Ferraz Station, BRA-62.0834, -58.3916
5.424341Esperanza Station, ARG-63.3991, -56.9810
6.655218(General Bernardo1) O'Higgins Station, CHL-63.3214, -57.8922
4.171-Great Wall Station, CHN-62.2157, -58.9675
4.156474(Henryk1) Arctowski Station, POL-62.1595, -58.4662
4.175
-		14515
-		Carlini3 Station, ARG
& Dallmann-Labor, DEU		-62.2385, -58.6678
4.178-King Sejong Station, KOR-62.2238, -58.7966
--Machu Picchu Station, PER-62.0921, -58.4717
4.2610659Orcadas Station, ARG-60.7382, -44.6991
5.4011184Petrel /Arg./ 2-63.4667, -56.2000
4.171
-		11571
-		(Presidente Eduardo1) Frei Station, CHL
& Professor Julio Escudero Station, CHL		-62.2001, -58.9655
4.4113267Signy 2, GBR-60.7177, -45.5992
7.35-Vice Comodoro Marambio Station, ARG-64.2418, -56.6224
(1) Additional part of name listed in Admiralty Sailing Directions.
(2) Registered as "Station" in Admiralty Sailing Directions.
(3) Until March 2012 Carlini Station was named Jubany Station.


Sea ice extension

Bootstrap Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I are provided by US National Snow and Ice Data Center (NSIDC). The borderline of 15 % ice coverage has been calculated by Sea Ice Service of BSH.

This picture shows the sea ice extension for the months January to December calculated for the median of the months from the years 1986 to 2006. The lines represents the border of 15 % ice coverage.
For final charting the extension for months February, April, June, August, October and December were adopted.
This picture shows exemplery the variabilities of sea ice extension for the month March taken different periods into account.
S-57 acronym for ice extension is ICEARE. Attribute CATICE defining the category of ice was set to "1=fast ice". To indicate the several extentions of ice coverage during the year, six borderlines were defined: February, April, June, August, October and December. In February the ice extension is minimal in August it is maximal. The period valid for the ice extension is defined in S-57 attribute PERSTA and PEREND and in textual form in attribute INFORM.
In INT-907 and corresponding ENC GB104907 an ice area in south western part of James Ross Island is documented, which is also defined in NGDC World Vector Shore Line dataset. As colleague Frank Nitsche from Lamont-Doherty Earth Observatory told, this ice area is already melted and will therefore not be displayed in INT-905.

Currents

Sea surface currents are registered on several positions within Weddell Sea area as following table exemplarily shows:

MoorIDInstrument Depth(m)LatitudeLongitudeEast-West Comp.(cm/s)North-South Comp.(cm/s)Speed(cm/s)Direction(°)Average Period (days)
AWI226 190.0 -70.3800 -13.5417 -6.67 -6.63 9.41 225.20 373.5
AWI225 270.0 -70.3183 -13.6600 -3.93 -3.16 5.04 231.17 100.2
AWI221 220.0 -66.2767 -30.2967 -1.01 0.36 1.07 289.49 453.0
AWI217 220.0 -64.4183 -45.8500 0.87 2.00 2.18 23.36 427.3
AWI217-2 266.0 -64.4168 -45.8305 0.94 1.74 1.98 28.40 750.4
mean217 243.0 -64.4176 -45.8402 0.91 1.87 2.08 25.82 1177.7
AWI216-2 241.0 -63.9600 -49.1467 1.49 1.89 2.40 38.24 698.8
AWI215-3 246.0 -63.3267 -52.7817 -0.37 1.00 1.07 339.50 691.8
AWI214-2 200.0 -71.0483 -11.6867 -9.27 -7.62 12.00 230.58 421.2
AWI214-3 210.0 -71.0550 -11.7350 -12.10 -9.52 15.40 231.81 307.9
mean214 205.0 -71.0517 -11.7108 -10.68 -8.57 13.70 231.27 729.1
AWI212-2 250.0 -70.9117 -11.9633 -7.03 -6.49 9.57 227.27 736.0
AWI211 247.0 -70.4917 -13.1167 -5.40 -6.44 8.40 219.97 433.5
AWI210 289.0 -69.6483 -15.7417 -1.11 -0.56 1.24 243.12 431.7
AWI210-2 270.0 -69.6600 -15.7150 -0.77 -0.12 0.78 260.90 392.1
mean210 279.5 -69.6542 -15.7284 -0.94 -0.34 1.00 250.11 823.8
AWI209 293.0 -66.6133 -27.1233 -0.30 0.11 0.32 290.26 427.8
AWI209-3 110.0 -66.6233 -27.1200 -1.40 0.43 1.46 287.09 801.0
mean209 201.5 -66.6183 -27.1217 -0.85 0.27 0.89 287.62 1228.8
AWI208 288.0 -65.6050 -36.4983 -0.30 -0.01 0.30 268.84 430.7
AWI208-2 230.0 -65.6350 -36.5033 -0.38 -0.24 0.44 237.75 418.4
AWI208-3 235.0 -65.6283 -36.4900 -1.00 0.23 1.03 283.15 798.2
mean208 251.0 -65.6228 -36.4972 -0.56 -0.01 0.56 269.32 1647.3
AWI207 263.0 -63.7633 -50.9050 0.02 1.13 1.13 0.90 434.6
AWI207-2 300.0 -63.7517 -50.9050 0.24 1.34 1.36 10.27 391.4
AWI207-4 255.0 -63.7217 -50.8200 0.31 2.39 2.41 7.30 694.8
AWI207-7 246.0 -63.7123 -50.8425 0.49 2.35 2.40 11.87 703.8
mean207 266.0 -63.7373 -50.8681 0.27 1.80 1.82 8.36 2224.6
AWI206 229.0 -63.4933 -52.1233 1.39 3.28 3.56 23.01 350.4
AWI206-2 260.0 -63.4933 -52.1050 0.93 3.86 3.97 13.53 210.9
AWI206-3 280.0 -63.4900 -52.1050 0.80 2.98 3.09 15.04 745.9
AWI206-4 222.0 -63.4933 -52.1010 0.40 1.69 1.74 13.39 693.5
AWI206-5 247.0 -63.5068 -52.1115 0.09 2.61 2.61 1.91 261.8
AWI206-6 241.0 -63.4795 -52.0962 0.97 2.22 2.43 23.48 489.7
mean206 246.5 -63.4927 -52.1070 0.76 2.77 2.88 15.39 2752.2
KN2 255.0 -71.1283 -12.1983 -15.26 -2.19 15.42 261.84 331.5

As you can see in 7th column the speed of currents are very slow and do not reach 1 knot. So they are assumed not to be significant for navigational purposes and will not be incorporated into the chart. Larger scale currents like tide driven currents nearby the coasts must be read from larger scale charts.



Magnetic variation (Isogons)

The magnetic variations within INT‑905 must not be displayed as single value but as isogons, because of the extension and polar near location of the map. The linked picture illustrates the situation. The isogons are provided by BSH M4106a.
S-57 acronym for magnetic declination is MAGVAR. Attribute RYRMGV defining the reference year was set to 2010. Values for magnetic variation are defined in attribute VALMAG and range from 16 to -14 degrees. Values for annual change are defined in attribute VALACM and range from -3 to -1 arc minutes.

Borders of other charts

The borders of charts of S-44 purpose 1 and 2 will be displayed in the paper chart as follows:
Neighbouring charts of same usage band (NO) 550 = INT-904, (GB) 4906 = INT-906, (GB) 4907 = INT-907 are mentioned in textual form at the corresponding borders of the chart.
The index frame of larger scale charts (GB) 3593, (AR) H-700 = INT-9170 are displayed within corresponding area.




Navigational lights

Due to generalization, not all lights are displayed. The names of adopted lights are highlighted. S-57 acronym for lights is LIGHTS. Following table shows the names of attributes for acronym LIGHTS as used in table stated below. This values are given for information but are not adopted in the chart because of the generalization of this small scaled chart.
Each light is logically situated on a landmark (S-57 acronym LNDMRK). The LNDMRK attribute CATLMK is set to 17="tower" and FUNCTN to 33="light support". Between LNDMRK and corresponding LIGHTS there is a master-slave relation established.
OBJNAMINFORM(position)LITCHAR
COLOUR
SIGPER		HEIGHTVALNMRTXTDSC

For INT-905 region following lights are registered in Admiralty Digital List of Lights (LL Southern Ocean Week 10/11)

Area 10 - Volume G - Southern Ocean - South Orkney Islands (GB)
   SIGNY ISLAND
G 1375- Signy Island60°42.4'S
45°35.6'W		F W24 m..Framework tower,
12 m		Occas
   LAURIE ISLAND. SCOTIA BAY
G 1378- Navidad60°45.28'S
44°41.95'W		Iso W 2s....White round GRP tower,
red top, 3 m
G 1378·5- Destacamento60°44.08'S
44°42.13'W		Fl W 3s....Lantern in radio mast
G 1379- Point Davis60°44.82'S
44°38.95'W		Fl W 5s....Red round GRP tower,
white band, 4 m
Area 10 - Volume G - Southern Ocean - Bransfield Strait - South Shetlands (GB)
   KING GEORGE ISLAND
G 1387·4- Arctowski62°09.5'S
58°29.0'W		LFl W 9s18 m8 nMWhite tower, red bands,
balcony		fl 3
G 1387·5- Martel Inlet62°05.0'S
58°23.6'W		ISO R 2s14 m10 nMWhite , red band,
on white framework tower,
4 m
   KING GEORGE ISLAND. MAXWELL BAY
G 1387·57- Potter Cove62°13.50'S
58°40.75'W		Fl W 10s6 m..White round GRP column,
red bands, 5 m		fl 0·5
Ra refl
G 1387·6-- Potter Peninsula. Teniente Cámara62°14.43'S
58°40.72'W		Fl W 4s18 m6 nMBlack tower,
yellow bands, 11 m		fl 0·5, ec 3·5
Ra refl
G 1387·7--- 62°14.07'S
58°39.28'W		Fl W 7s10 m3 nMYellow round truncated
conical GRP tower,
orange bands, 7 m
   KING GEORGE ISLAND
G 1387·8- Fildes Peninsula. Jasper Point. Uruguaya62°11.4'S
58°54.4'W		Fl W 5s52 m6 nMWhite aluminium truncated
pyramid, red band, 5m		fl 0·5
Shown November to March
G 1387·9- Maxwell (Fildes) Bay. Ardley Cove62°12.04'S
58°57.60'W		Fl W 5s5 m6 nMWhite GRP tower,
red band, 5 m		fl 0·4
Vis 256°-287°(31°)
Shown November to March
G 1388- Ardley Island62°12.8'S
58°55.8'W		Fl W 10s45 m6 nMOrange round tower on
truncated conical tower,
black bands, 6 m		fl 0·3
Area 10 - Volume G - Southern Ocean - Drake Passage - South Shetlands (GB)
   CLARENCE ISLAND
G 1388·2- Cape Lloyd61°07.5'S
54°00.0'W		Fl W 10s113 m6 nMWhite GRP tower,
red band, 3 m		fl 0·5
Area 10 - Volume G - Southern Ocean - Antarctica (GB)
   ANTARCTIC PENINSULA. ANTARCTIC SOUND. HOPE BAY
G 1389-Grunden Rock. S side63°23.8'S
56°58.0'W		Fl W 2s26 m6 nMRed round tower,
black bands, 6m		fl 0·5
G 1389·2-Jagged Rocks. Lts in line 214°. Front63°23.89'S
56°58.98'W		Iso W 2s12 m5 nMBlack on green
column, yellow top, 3 m
G 1389·21---Rear. 300m from front63°24.02'S
56°59.18'W		Fl W 3s14 m10 nMBlack on green
column, yellow top, 3 m		fl 1



Underwater obstructions

In neigbouring chart INT-907 (GB104907) underwater rocks are displayed to indicate possible shipping obstructions. In lack of any information of this kind, the data of British chart was adopted. So these information are available for intersecting area between these two charts only (west of 53°W). S-57 acronym for underwater rocks is UWTROC.

Caution areas

Because of the incomplete information about above mentioned underwater obstructions, caution areas were defined to be all chart areas shallower than 200 meter. The boundaries were snapped/referenced from 200 meter contour line. For better and clearly reading of the map, areas shallower than 200 meter were not defined explicitely as caution area, if they are very small and not shallower than 100 meter. Also deeper areas inside 200 meter contour were not cut out. S-57 acronym for caution areas is CTNARE.
On the border of the paper chart these areas are mentioned as note in english and german language as follows:

SHELF AREAS
Shelf areas up to 200m depth contour are shown
in dark blue. Information on depths, aids to
navigation and obstructions may be incomplete. 		SCHELFGEBIETE
Schelfgebiete bis zur 200m-Tiefenlinie sind in
dunkelblau dargestellt. Angaben über Tiefen,
Schifffahrtszeichen und -hindernisse können
unvollständig sein.

IALA Maritime Buoyage System

The International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA) defines two buoyage regions, which both are applied within INT-905 chart area. The regions are defined by S-57 acronym M_NSYS attribute MARSYS.
Buoyage Region A: (11°W - 20°W); Value for MARSYS: 1="IALA A"
Buoyage Region B: (20°W - 59°W); Value for MARSYS: 2="IALA B"
(These information are given without warrenty, because IALA has actually not accredited the system for southern ocean region).

Administration Area

The Area of Antarctic Treaty System is defined to be the world's region south of 60° S.
S-57 acronym is ADMARE, attribute JRSDTN is 1="international". On the border of the paper chart these areas are mentioned as note in german and english language as follows:

ANTARKTISVERTRAG
Innerhalb der Kartengrenzen gelten bestimmte Ein-
schränkungen und Regelungen des Antarktis - Ver-
trags. Einzelheiten dazu finden sich in den Admi-
ralty Sailing Directions NP 9 und den South African
Sailing Directions Vol. III SAN HO-23, Kapitel 10. 		ANTARCTIC TREATY
Certain Antarctic Treaty restrictions and regula-
tions apply within the limits of this chart. For
details of these see Admiralty Sailing Directions
NP 9 and South African Sailing Directions Vol III
SAN HO-23, Chapter 10.





Chart production

The production of Electronic Nautical Chart (ENC) and paper chart was executed using products from CARIS. In CARIS products the "mapdef.dat" files were extended in section "[World Mercator]" by row
WRLDMERC60,"World Mercator 60",NEMR,WG84,ME,60,0,0,0,1,0,0,0
to provide projection parameters mandatory for this chart.

Raw data editing

Raw data of swath sonar bathymetry measured during R.V. Polarstern cruises (as listed in section Hydroacoustic data) have been edited using software Application CARIS HIPS/SIPS 6.1 Swath Editor. The ship tracks were heading through ice covered area extensively, so the hydroacoustics and raw data were affected by rough errors. These errors can not be decimated by automatic algorithms satisfactory and therefore manual editing has been executed using CARIS Swath Editor.

Calculation of grids

Grids are calculated as intermediate product for sounding calculation.
Swath sonar bathymetry has been calculated into regular grids of CARIS format csar applying CARIS HIPS. The grids are defined to be mercator projected with latitude of origin of 66° (-66°) and grid spacing of 500 meter. Gaps were interpolated by 5x5 filter. Achieve smaller files and better performance during the work, not one grid covering complete INT‑905 area was calculated but six sub grids intersecting each other by 5 arc min (ca. 9.3 km).
Swath sonar bathymetry provided by UKHO was delivered by 165 files as point clouds in CARIS csar format. These files were combined to 6 grids with same boundaries like those calculated from Polarstern bathymetry.
As this picture shows there are depth differences between singlebeam and multibeam bathymetry. The quality of R.V. Polarstern bathymetry is well known and documented and can be seen to be free from errors after manual editing. Furthermore, because of the swath width and the resulting higher number of beams/depths, a higher trustworthiness of multibeam data can be assumed compared to singlebeam profiles. Therefore, differences between singlebeam and multibeam data have been asserted to be errors in the singlebeam data and have been fixed in that datasets.
To give the multibeam data the advantage against the singlebeam data, some rules for dataset merging needed to be defined. The date of the singlebeam datasets were set to be earlier than those from multibeam data and if a cell is covered by both singlebeam and multibeam depths, the newest depth was taken into account. Single beam and multibeam datasets of same regions were combined using CARIS Base Editor 3.0.



Calculation of soundings

Calculation of soundings was executed applying CARIS Base Editor 3.0. Two datasets of soundings were calculated from the six combined subgrids: first dataset was generated with sounding density of two milimeter for charted scale of 1:2,000,000. This dataset was used for manual adjustments of contour lines as described in next section. Second dataset was generated for final charting with depth varying density of soundings:
Depth interval [m]density [mm]
0 - 50015
500 - 100020
1000 - 200025
2000 - 400030
4000 - 800035
Both sounding sets were calculated taking shallowest depth into account.
After contouring as described in next section, the dataset has adjusted by means of deletion and addition of soundings representing significant topographic structures and to make the morphology better readable. Calculated soundings have beed deleted, if they were situated too near to contour lines and were overlaped by them. Soundings have also been deleted, if outliers in the grids (with source of singlebeam depths) were used to generate soundings (setting: use shallowest depth). In a screenshot linked here you can see two wrong soundings selected for deletion. Another reason for manual sounding definition is to make the track lines recognizable to give an easier view for unsurveyed areas. Depths for manually defined new soundings were adopted from the grids. Following IHO publication S-4 section B-412 the soundings were rounded as follows:
Depth interval [m]Rounding
0.1 - 21down to nearest decimeter
21 - 31down to nearest half meter
thereafterdown to nearest meter
The attribute QUASOU of acronym SOUNDG is set to 1="depth known" for all soundings.

Contouring and morphologic modelling

Calculations of grids, soundings and contour lines from hydroacoustic data were executed applying CARIS Base Editor 3.0.
As preview images (linked in section Hydroacoustic data) show, not the complete INT‑905 area is covered by hydroacousic measured data but large gaps exists. Therefore, contour lines calculated from these data look anomalous as can be seen here. Especially in flat areas the contours show insignificant lines following small scale depth differences. For that reasons additional information where taken into account and to model the morphology of the unsurveyed areas. This task was executed during production of the AWI Bathymetric Chart of the Weddell Sea (AWI-BCWS) and this product was used as base for contouring.
Contours of AWI BCWS were compared to first sounding set, described in previous section. If contours did not fit to the soundings they were adjusted manually as the linked screenshot shows.
In case of "wrong" singlebeam profiles, the contours were manually adjusted to generate smooth curves as can be seen in following two pictures: 1st picture shows the wrong soundings highligted and the corresponding contour lines. 2nd picture shows the situation after contour adjustment.



Quality assessment

The quality of data within ENC is described as areal feature (Zone Of Confidence - ZOC) of S-57 class M_QUAL. Values of attribute CATZOC are defined in IHO publication S-4 in section B-297 as follows:

ZOCPOSITION
ACCURACY		DEPTH
ACCURACY		SEAFLOOR
COVERAGE
A1± 5m=0.50m + 1%dAll significant seafloor features
detected
A2± 20m=1.00m + 2%dAll significant seafloor features
detected
B±50m=1.00m + 2%dUncharted features hazardous to surface
navigation are not expected but may exist
C±500m=2.00m + 5%dDepth anomalies may be expected
DWorse than
ZOC C		Worse than
ZOC C		Large depth anomalies may be
expected
U Unassessed - The quality of the bathymetric data has yet to be assessed.
MDSC Maintained Depth Sea Chart

Multibeam data recorded on board R.V. Polarstern with sonar system Hydrosweep DS match quality requirements of zone "A2" except for shallow waters of order "special" and "1a" by means of IHO publication S-44 (version 5). Singlebeam data do not reach the areal qualtiy of multibeam data and are sometimes provided as primary data without processing. Because of relations to neigbour depths by means of geologic constraints outliers, errors or other suspicious data can be detected and decimated during final chart production. As an example this picture show the differences of singlebeam data recorded by a scientific institute compared to the global dataset of GEBCO. A comparision of singlebeam data versus multibeam data shows the lower quality of provided singlebeam data as well. Because not all erroneous data were detected and erased and morphologic modelling might not be optimal, the singlebeam data will be described by zone "D". Areas not surveyed but modelled using additional global datasets and geologic correlations can be assigned to zone "U".

Nevertheless - because of the small scale, the generalization of final data, the irregular traced profiles and the large number of gaps between the profiles the decision was made not to confuse the chart user by defining too many too small areas. So the value "D" for attribute CATZOC was assigned to all wet ares and value U="unassessed" for all land areas.
In the paper chart a source diagram is displayed showing the multibeam tracklines provided by AWI (blue) and singlebeam tracklines of several international institutions and organizations provided by UKHO (green).

Final chart production

Regulations for INT charts and chart specifications are documented in IHO publication S-4. Content of INT‑905 as listed in section "Chart content" was combined into one Caris HOB-file. The consistency of this vector dataset was verified with software application TerraSond dKartInspector and after imported into CARIS Hydrographic Production Database (HPD) at BSH with validation tool of Caris HPD Source Editor 2.8.2 additionally.
Primary data are saved and described at BSH on network device "X:\nautische Hydrographie\nautischer Informationsdienst\2-Produktion\1-Quellenmanagement\AntarktisQuellen\2011\".

The production of Electronic Nautical Charts (ENC) follows standardisations documented in IHO publication S-57. The production of the ENC was executed with CARIS Product Editor. Compilation scale was 1:1,500,000.
Electronic nautical charts of same IHO S-44 purpose must not be overlapping. Neigbouring ENCs INT‑904 (NO1A5500) and INT‑907 (GB104907) already exists, so the extent of INT‑905 (DE160000) is downsizing to boundaries:   59°10'S - 71°00'S / 53°00'W - 15°00'W (see boundary scheme). The area of ENC must be created to be rectangular. To indicate valid areas and areas covered by neighbouring charts of same usage band, the S-57 meta object M_COVR must be defined. Attribute CATCOV has two different values: 1="coverage available" and 2="no coverage available". The south western part of chart INT‑905 contains more information than neighbouring chart INT‑907. The more information will be delivered to the UKHO to add them into their products.
The source and date of all used primary data for chart production are indicated by S-57 acronym SORIND and SORDAT. The value for SORIND is a composition of four parts:
country codeDE - Germany
producing agencyDE - Bundesamt für Seeschifffahrt und Hydrographie
type of sourcepublication, report or graphic
source idname of source and/or specific number of dataset or dataset entry

The production of the paper chart was executed with CARIS Paper Chart Editor. Cartographic regulations are given in IHO publication INT-1. Paper size of the chart is A0 (DIN-A0 = 841x1189 [mm] or ISO-A0 = 860x1220 [mm]).
The chart consists of one panel displaying the whole extent of the chart. No further panels of larger scale showing special parts of the chart in greater detail are included.

Chart production was kindly supported by colleagues of BSH in Rostock section N - Nautische Hydrographie:
Arvid Elsner: production of ENC. Holger Fasterding: support to S-57 standards. Sven Heiland - supporting work with Caris Base Editor. Bert Käding - paper chart production. Jana Vetter - supporting work with Caris HPD and data validation. Also thanks to Andrea, Anja, Conni, Iris, Michaela, Tommy and Udo for genial atmosphere.

Updates

Actually, there is no update planned for paper chart INT‑905 and ENC DE160000.
An update of neighbouring larger scale paper chart INT‑9055 (and INT‑9057) and ENC DE260001 is planned to fix some errors and differences between them and to harmonize the datasets of these both products and INT‑905 chart. Some misspelling and topologic errors between contour lines and soundings need to be edited. The exposition of soundings will be optimized as well as the course of contour lines. The Antarctic Treaty Area will be defined as administration area (ADMARE) and no longer as caution area (CTNARE).




Products

Electronic Nautical Chart (ENC)

Name of ENC: DE160000
(Availability of product was planned for II,2012)


[Screenshot of north western part of ENC DE160000]

Paper chart

ISBN:
Edition:
(Availability of product was planned for II,2012)
Additional information about purchase the chart is given by BSH.

Metadata description

(Availability of product was planned for II,2012)

Corresponding project

As previous charting project in the Weddell Sea the production of nautical charts INT-9055 and INT-9057 (DE-1701 and DE-1702) was accomplished in the year 2007/08.
For project details (in German language) see: Rathlau (2008).
Primary data are saved at AWI on network device "/bats1/data1/coolchart/".

Clink on image to sea a larger scale preview.
  
See also info page at BSH.




Last update: 21.12.2016Imprint