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Diving Deeper: Episode 29 (December 16, 2010) - Historical Charts and Maps

HOST: Welcome to Diving Deeper where we interview National Ocean Service scientists on the ocean topics and information that are important to you! I’m your host Kate Nielsen.

Today’s question is….Why do we archive nautical charts and maps?

NOAA’s Office of Coast Survey maintains an online collection of digital scans of historical maps and nautical charts. Historical maps and charts are used by many different people for a variety of purposes.

To help us dive a little deeper into this question, we will talk with Meredith Westington on historical charts and maps. Meredith is NOAA’s Chief Geographer at the Office of Coast Survey. Hi Meredith, welcome to our show.

MEREDITH WESTINGTON: Hi Kate, thanks for inviting me. I’m excited to share some of the details about the Historical Map and Chart Collection with our listeners.

HOST: Meredith, what exactly is a historical map or chart?

MEREDITH WESTINGTON: Well Kate, in the context of NOAA’s Historical Collection, a historical map or chart is any map or chart that’s not used today because it’s out of date. The product may not list the most current navigation obstacles, water depths, or shoreline—just to name a few items that are frequently updated on NOAA’s nautical charts which are produced by NOAA’s Office of Coast Survey. Other maps may depict historical events against the geographic landscape at that time. Our collection of maps depicting the Civil War battle sites are good examples.

HOST: Meredith, we talked about this in an earlier episode of Diving Deeper, back in March 2009 with your colleague Tom Loeper, but can you remind everyone about the difference between a map and a nautical chart?

MEREDITH WESTINGTON: Sure, Kate.There’s actually many differences between a map and a nautical chart. In terms of nautical charts, they have a very specific purpose and that is to provide mariners with the information that they need to safely move along the water. Information will include water depths, shoreline, tide predictions, obstructions to navigation such as rocks and shipwrecks, and even navigational aids such as buoys. Because of its critical importance in promoting safe navigation, the nautical chart also has a certain level of legal standing and authority.

To me, the term “map” is more all-encompassing of various geographic and cartographic products. Maps can convey information similar to nautical charts, but I believe the audience is much broader. Some examples of maps might be road maps or atlases, city plans. Another example, which is contained in our online collection, is bathymetric maps. Those are maps that depict just the water bottom without any navigational aids that you would actually see on a nautical chart.    

HOST: How far back do our maps and charts go?

MEREDITH WESTINGTON: Well, that’s an interesting question. Our collection of historical maps and charts dates to the 1700s, but the Office of Coast Survey, which formed in 1807 as the first federal scientific agency, produced its first charts in the early 1840s. That was after several decades of fundamental land-based and offshore survey work.

Some interesting things that you might find in the collection are from 1803 we have the King Plats of the City of Washington, which are public streets rights-of-way in Washington, DC. We have sketches of Anacapa Island in California which is from 1854, it was created by James McNeill Whistler, who some may remember for his great works of art, but he was actually employed briefly at the Office of Coast Survey as an engraver. And we also have a Chattanooga battlefield map from 1863 which is considered one of the best Civil War maps at that time. It’s a far ranging collection.

HOST: Meredith, what do NOAA’s historical charts and maps cover? Is it just our coastal waters?

MEREDITH WESTINGTON: More or less that’s true. When the Survey of the Coast was formed in 1807, the agency was responsible for surveying and charting only the Atlantic Coast of the U.S., which was at that time approximately 15,000 statute miles of shoreline.   Today’s nautical charts cover 95,000 miles of shoreline, cover the Great Lakes, and include 3.4 millionsquare nautical miles of U.S. jurisdiction within the Exclusive Economic Zone, which is an area that extends 200 nautical miles from shore. Our historic charts also cover areas of historic U.S. interest, which include the Philippines. 

HOST: Why do we need to archive historical maps and charts?

MEREDITH WESTINGTON: Well, the historical maps and charts, I think they give us all a reference to the past from which we learn and we make decisions. Based on our experience from listening to other customer stories, it’s hard to put a value on the collection with such a diverse interest and use. It’s safe to say that the collection is largely sentimental in value, but it shouldn’t go unnoticed that people, including my office, use the collection to resolve legal disputes to often involve some monetary settlement. 

HOST: Meredith, you've touched on this some already, but who uses historical charts and maps?

MEREDITH WESTINGTON: Well, the short answer is – lots of people. Since we posted a link on our website last year and we sort of passively prompted people to tell us their stories about how they’re using the collection, I’ve been amazed at the variety of applications for our products. What I’ve learned is historians are not the only ones who are using the collection. 

We’ve heard stories that the historical images are used for coastline or land change analysis, for transportation route analysis, for what I refer to as anthropological research – a lot of Civil War and pre-Civil War era work studying how people lived at that time. Ecological studies, geologic studies of ocean bottom features, and even as I said before, legal cases involving public and private land ownership rights. Even beyond legal and scientific purposes, we’ve also had people use the charts for book illustrations and home remodeling and decorating and movie set design.

HOST: Wow, so really a little of bit of everything – that’s great. What is the most unique or interesting way that you’ve heard of that someone has used one of our historical charts or maps?

MEREDITH WESTINGTON: Wow, that’s a tough one to answer. I think for me, I was sort of taken aback when I had heard that a romance novelist was actually using our collection. I was not anticipating that, but I thought it was pretty cool.

HOST: How do we use historical maps and charts to assess environmental changes over time?

MEREDITH WESTINGTON: The charts contain data such as shoreline, water depths, and sea bottom characterizations. All this data is compiled using high scientific standards. It’s because of that very standard approach to data collection that people can and do track changes over time.

HOST: Meredith, you mentioned several times that maps and charts can be used in legal cases, can you expand on that?

MEREDITH WESTINGTON: Yes. Since mariners rely on NOAA charts to plan out the best and safest routes, NOAA charts are often used in legal cases involving disasters at sea when uncharted hazards to navigation are suspected to have played a role. One example would probably be, there was a highly visible case dealing with the Queen Elizabeth II, which was a large ocean liner, grounding in Buzzards Bay, Massachusetts in 1992.

And in that particular case, we were instructed to basically monitor one particular chart and follow our processes for applying new hydrographic surveys over a four-year period following that grounding. We’ve also had instances where charts were referenced in cases involving land ownership rights along the coast because the shoreline that we show on our charts has a reference to specific tidal levels that often align with legal public and private rights and jurisdictions on the land and on the adjacent seabed, those shorelines are very important to a large number of our users. 

HOST: It’s great to hear about a product that initially has such a specific use for safe marine transportation, to hear about all the different ways that it’s used historically, not just as a pretty framed picture up on somebody’s office wall, but how it’s being used for everything from environmental to legal cases to movie sets to romance novels. Meredith, what is the role of the National Ocean Service in preserving the nation’s historical charts and maps?

MEREDITH WESTINGTON: Well, that’s a good question Kate. My office, the Office of Coast Survey, which is a part of the National Ocean Service, has published thousands of products over the last 200 years. In forming the Historical Map and Chart Collection, our primary interest has been about making the historical assets accessible. I suppose anyone could have scanned our maps and charts, but we were the first to recognize the need-- not only for own purposes, but to support other’s needs as well. We’re pretty proud of our heritage as the first federal scientific agency. By hosting the collection, we have the opportunity and the knowledge base to support our customers on questions about the collection. 

HOST: What’s involved in preserving these maps and charts, especially some that you’re saying are over 100 years old?

MEREDITH WESTINGTON: Well, we began our project in 1995. At that time we had a printing facility in an old warehouse in Maryland, that was shutting its doors and planning to throw away thousands of old maps and charts that were tucked away in map drawers. We were asked if we wanted to do anything with those maps and charts before they moved them to the trash. We actually stepped in and said yes, we’re going to scan them. 

So, that was the beginning of the scanning effort and there was one person in our office who actually recognized this need to preserve our assets and make them accessible. So he actually got together some grant money and a couple of scanners and some contractor services. We set out the standards for the file type, the image resolution, the file naming convention, and the chart information that we wanted to record – it was pretty critical that we set out those standards up front because then the massive scanning effort began.

We concluded scanning the documents in the warehouse probably around 2003. And since then we’ve located some other assets within the National Archives and also with the Library of Congress that have not been scanned. Currently, we have 35,000 images in the collection and it’s one of the most comprehensive collections of historical maps and charts, I would say in the world. Even still, I can say that it’s not complete with respect to everything that NOAA and its predecessor agencies have produced. That’s 200 years of history to account for, and it’s a big task.

HOST: Meredith, how long will it take to archive all of these charts and maps?

MEREDITH WESTINGTON: Well, right now, we’re in the midst of a major effort to obtain a full catalog of all the charts produced by NOAA and its predecessor agencies. This effort includes identifying what our agency produced—a surprisingly difficult task because there isn’t an all-encompassing catalog out there. The NOAA Library started to identify some NOAA assets at the National Archives and scanned those around 2008 timeframe. In addition, we have a partnership with the Library of Congress to support them in creating an inventory of their collection and scan all of their documents. That collection is actually about 28,000 charts and they all reside in map drawers and they are not inventoried. So, it’s a very similar setup to what we had in the warehouse, except we know that they’re all Coast and Geodetic Survey products. The warehouse was a little bit different in that respect. But our hope is that we will acquire digital scans of all NOAA produced charts and be able to provide the best copies to the public.

And after this major effort to sort of retrace history, NOAA actually publishes between 100 to 200 new chart editions every year. So, our goal is to place every retired edition chart within the Historical Map and Chart Collection. As soon as a new chart edition comes out the old one goes in the historical collection. So, I think it’s safe to say that the archiving process will be continual. 

HOST: So Meredith, what all is in this collection? How diverse is it?

MEREDITH WESTINGTON: Well, it’s probably not surprising that with over 200 years of scientific leadership in surveying and mapping, that the collection is quite large. To name a few items, it includes nautical charts of U.S. waters – that’s what you would probably expect it to definitely have in it – and that includes current and former territories and possessions, there’s also Civil War maps, sketches which includes instrument diagrams because we have scientific leadership there’s actually instrument diagrams in there, there’s isogonic maps and gravity maps, bathymetric maps, aeronautical charts, and city plans. The core collection contains whatever NOAA and its predecessor agencies produced, which also includes the U.S. Lake Survey charts. The U.S. Lake Survey became a part of NOAA in 1970. The Coast and Geodetic Survey charts, the beginning of NOAA anyway, they date back to the 1840s.

And then we’ve got loads of stuff in there that are non-NOAA produced maps. Some of them are because NOAA supported the work, either by providing the man power or the data. Other images are in the collection because quite frankly since we were scanning stuff that we did not know, it was not inventoried in the warehouse, we were just pulling map drawers and whatever was in the map drawer got scanned.   

HOST: Meredith, where are the maps now and where will they ultimately be archived?

MEREDITH WESTINGTON: Well, first off, I should make some distinction between the paper products that we send directly to the National Archives and have for some time and make sure that they are appropriately archived, and the difference between that and the digital preservation efforts that we’ve been working on.

The digital collection that we have actually contains high-resolution scans as well as two versions of some lower-resolution images. The high resolution scans are actually TIFF formatted images and they’re usually about 300 dpi, which is dots per inch, the lower-resolution images are JPG and then also a tiled JPG. The JPGs are for web download and the tiled JPGs are for the web preview function that we have through our website. All three of these images, they’re all currently on CDs and also backed up onto network storage devices.

We’re also looking at some longer-term ways of storing our, basically all of the work that we’ve done for so many years now given the amount of time and resources that have gone into this project since 1995, we’ve been talking with the National Archives and the Library of Congress to coordinate on some longer-term preservation. 

HOST: How can the public access these charts and maps?

MEREDITH WESTINGTON: Well, you can go to the Office of Coast Survey website, which is, and from there you can link to the Historical Map and Chart Collection or you can go directly to our website by adding “/history” to our URL. From there you can click on a link to browse the collection. You can search by a number of parameters. You can preview the images and you can download the images. All the images are available to the public for free.

Also in terms of improving accessibility, we’re looking at expanded search options. We are in the midst of upgrading our website, we’ve had the same one up since 2001, and we’re looking at opening up a website that allows people to search by geographic parameters including by place name. Some of the benefits of this particular upgrade would be, for example, if someone wanted to search for a chart of Virginia Beach in today’s current website, they would basically have the option of typing Virginia Beach into the keyword search and that would actually search for the name Virginia Beach within the chart title and your results would only be two charts.

The other option would be to search for all of the charts within the state of Virginia and that would give you over 1,000 results, at which point you could go through all of those and find the ones that actually cover Virginia Beach. Our hope is that in the new version of the website, you can actually click on, within a map, you can actually click on Virginia Beach and get the search results for that particular location.

HOST: Meredith, do you have any final closing words for our listeners today?

MEREDITH WESTINGTON: Sure. We’ve really enjoyed the user feedback we’ve received over the last year or so and I’d really like to thank those people that have reached out and shared their stories with us. I’d really encourage new users and even our existing users to keep that dialogue open because that’s the kind of stuff that really keeps us motivated and encouraged about why we do what we do. So, thank you.

HOST: Thanks Meredith for joining us on Diving Deeper and talking more about historical charts and maps and the many ways that these products are being used even today. To learn more, please visit

That’s all for today’s show. Please join us for Diving Deeper Shorts in January.