Archive for the ‘Cartography’ Category
The “slave density map,” created by the men of U.S. Coast Survey in 1861, is one of Coast Survey’s most treasured historical maps. Artist Francis Bicknell Carpenter included it in his painting, “First Reading of the Emancipation Proclamation of President Lincoln,” because Lincoln consulted it so often in devising his military strategy. According to Carpenter, President Lincoln used the map in his decisions to send his armies to free blacks in some of the highest density areas in order to destabilize Southern order.
Francis Bicknell Carpenter placed the “slave density map” in the lower right corner of his painting of the Emancipation Proclamation.
President Lincoln’s Cottage, now maintained by the National Trust for Historic Preservation, is where President Lincoln developed the Emancipation Proclamation. So it was fitting that, on Lincoln’s birthday this year, NOAA’s Office of Coast Survey presented a copy of the map to Cottage officials, to assist with their vital educational programs.
In the very library where Lincoln may have studied the map, Coast Survey’s Dawn Forsythe (left) and NOAA’s Ben Sherman (right) presented the map to Erin Carlson Mast, the Cottage’s executive director, and Callie Hawkins, associate director for programs.
Dawn Forsythe (Coast Survey), Erin Carlson Mast and Callie Hawkins (Lincoln’s Cottage), and Ben Sherman (NOAA) with a copy of the slave density map in the Lincoln Cottage library.
The Cottage plans to use the map in their educational programs. To learn more about the map, see Mapping Slavery in the Nineteenth Century.
The men of Coast Survey created the map to help the public understand the secession crisis, by providing a visual link between secession and slavery.
There are literally millions of pieces of data on nautical charts. How do cartographers determine which data to put on the charts? Two Coast Survey cartographers, Paul Gionis and Lance Roddy, explained some of the processes, protocols, and NOAA charting requirements to participants at the Florida Artificial Reef Summit earlier this month. (See the archived video of their presentation, starting at 55:40.) Among their many duties, these cartographers are responsible for vetting artificial reef public notices and permits from the U.S. Army Corps of Engineers, and for acquiring source data from the state and county reef coordinators.
By explaining the nautical chart aspects of planning, creating, and maintaining fish havens, they hoped to smooth out the permitting and charting phases.
(By the way, in case you’re wondering what we mean by “fish haven,” Coast Survey’s Nautical Chart Manual defines them as “artificial shelters constructed of rocks, rubble, boxcars, boats, concrete, special designed precast structures to enhance fish habitats, remnants of oil well structures, etc., that are placed on the sea floor to attract fish. Fish havens are often located near fishing ports or major coastal inlets and are usually considered hazards to shipping. Constructed of rigid material and projecting above the bottom, they can impede surface navigation and therefore represent an important feature for charting.”)
Permits issued by the Army Corps of Engineers are the sole source for classifying obstructions as artificial reefs and fish havens for charting purposes. Specific essential information needs to be provided for charting the areas.
- Cartographers need accurate geographic coordinates and dimensions, and the “authorized minimum clearance” (safe vessel clearance) for each distinct reef boundary.
- Importantly, the designated area cannot conflict with charted features. For instance, we cannot designate artificial reefs or fish havens in safety fairways, restricted areas, anchorages, or entrance channels. It almost goes without saying that we also don’t want to place reefs in missile test areas, or areas with pipelines, cables, or unexploded ordnance.
- The cartographers must receive notice of deployment (telling us that construction has begun).
A good example of how Coast Survey works on charting artificial reefs is the initial reef proposal for Port Everglades chart 11466. The initial proposal designated a minimum clearance of 7 feet – which would prevent a mariner from transiting the area even though the water is very deep. The proposed reef area also conflicted with two established anchorages for commercial ships waiting to enter the port.
Initial reef proposal
After working with the Corps of Engineers and project planners, Coast Survey was able to split the area and chart three separate bands with progressively deeper minimum depths, from seven feet to 60 feet of clearance. They also avoided overlap with the charted anchorages. The solution prevented navigation conflicts and protected the artificial reef.
Charted fish havens were banded by progressive depths, and excluded anchorages.
The cartographers appreciated the chance to talk directly to Florida’s artificial reef community. “Events like these provide an expansive avenue to articulate Coast Survey requirements for promoting safe and efficient navigation,” Gionis points out.
Coast Survey’s navigation manager for Florida, Mike Henderson, is our charting representative on the ground in that state, and is available to work on future projects as well as answer charting inquiries in general.
Knowing the locations of shipwrecks and other obstructions has always been important for safe navigation ‒ but mariners are not the only people who want to know about wrecks. They are also important for marine archeology, recreational diving, salvage operations, and fishing, among other interests. Now, Coast Survey has improved our Wrecks and Obstructions Database, giving everyone easy access to new records to explore.
Coast Survey’s wrecks and obstructions database provides info on thousands of wrecks.
Historically, Coast Survey has maintained two separate sources of information on wrecks. We recently combined the sources, bringing together information on nearly 20,000 wrecks and obstructions.
Coast Survey established the Automated Wreck and Obstruction Information System (AWOIS) database in 1981 to help estimate the level of effort required to investigate items during a planned hydrographic survey, but maritime users were also interested in AWOIS’ historical records. However, because the emphasis is on features that are most likely to pose a hazard to navigation, AWOIS has always had limitations. Most notably, AWOIS is not a comprehensive record and does not completely address every known or reported wreck. Additionally, for a number of reasons, AWOIS positions do not always agree with a charted position for a similar feature.
Coast Survey compiles NOAA’s electronic navigational charts (NOAA ENC®) from sources on features that are navigationally significant. As the official chart data used in electronic chart and display information systems (ECDIS), ENCs are the authoritative source of information about known or reported wrecks and are much more comprehensive than AWOIS. However, the features in an ENC typically lack the historic information and context provided by AWOIS.
Correcting for some overlap between the two source databases, Coast Survey’s new wrecks and obstructions database now contains information on about 13,000 wreck features and 6,000 obstructions. Wreck features from each original database are stored in separate layers but can be displayed together. Users may also choose a background map from several options.
The new database also offers users additional data formats from which to choose. Historically, shipwreck data in AWOIS was available in Adobe PDF and as Microsoft Access Database (MDB) format. More recently, KML/KMZ files replaced PDF and MDB formats, making it easier for public users to view AWOIS data, by using freely available software such as Google Maps or Google Earth. Now, in addition to KML/KMZ and Microsoft Excel formats for general users, Coast Survey provides the data in ArcGIS REST services and OGC WMS services, for use in GIS software programs or web-based map mashup sites.
In November 2013, we introduced NOAA ENC Online – a continuous viewer for our electronic navigational charts. You can click on the web map and zoom to selected features or locations, to see the information contained in over a thousand electronic charts of NOAA-charted waters. Each zoom moves you through an ENC depiction that takes into account the ENC scale and other attributes that are encoded in the ENC, allowing features to become visible or invisible as you seamlessly zoom in and out of the data.
NOAA ENC Online is based on Esri’s Maritime Chart Server.
Now this latest release of NOAA ENC Online lets you:
- Set a shallow and deep depth contour, which changes the shading to those parameters
- Set a safety contour (In electronic charting systems, the safety contour is set based on the ship’s draft changes the depiction of rocks, wrecks and obstructions to isolated dangers depending on if the water is “safe” or “unsafe” for vessel navigation.)
- Change between S-52 simplified and S-52 traditional symbols
- Change the background colors of the display based on the S-52 color palette for different light conditions on the bridge of a ship
- Turn off certain features based on different categories such as buoys and traffic routes
NOAA ENC Online is not certified for navigation. It does NOT fulfill chart carriage requirements for regulated commercial vessels under Titles 33 and 46 of the Code of Federal Regulations.
by Meredith Westington, Coast Survey geographer
Good, informed decisions are often based on analyses of historic and present conditions. Researchers, decision-makers, and amateur history buffs find detailed documentation of past conditions in the thousands of Coast Survey charts, dating back to the mid-1800s, in our Historical Map and Chart Collection.
Just like present day nautical charts, historic charts contain a wealth of information about geographic features — including their names, shape, and condition. Geographic names are important locational references for today’s emergency responders, but current and historic names also convey important aspects of local people and culture, which may persist through time.
As Coast Survey’s nautical cartographers routinely apply new topographic and hydrographic data to improve decisions at-sea, a question arises about names when a geographic feature, such as an island, bay, or bayou, has changed: does the associated place name disappear when the geographic feature is no longer there, or does the local population still use the historic name to convey a shared sense of place?
Coast Survey cartographers raised this exact question after applying new shoreline information to charts covering Louisiana. When cartographers applied new shoreline data to charts 11358 and 11364 in 2011, they found that named features were no longer there (see the images below for a comparison of today’s landforms vs. the historic landforms in 1965). In early 2013, another new shoreline survey similarly affected fourteen geographic names on chart 11361. They removed these “dangling names” to reduce chart clutter, but are there new names for the areas where the features used to be?
Losing places (and their names) may mean losing important locational references. Some of these places have appeared on NOAA’s nautical charts of Louisiana since the late 1800s, so their removal raises concerns about a loss of cultural identity on the landscape. For example, Cyprien Bay was named for longtime resident Cyprien Buras. The names live on, of course, on the historic maps and charts in Coast Survey’s Historical Map and Chart Collection. Importantly, they are also retained in the lesser-known U.S. Board on Geographic Names’ federal repository of place names, the Geographic Names Information System. The system’s current and historical records make a great starting point for finding names that you can use to locate relevant historical nautical charts in the Historical Map and Chart Collection. The collection has an easy-to-use geographic place name search function. Just type in a name, and start to explore our nation’s geographic changes…
Search over 35,000 historical maps and charts, just using a geographical name.