Archive for the ‘Archaeology’ Category
By Ensign Max P. Andersen
Formed by retreating ice sheets over 14,000 years ago, the Great Lakes have long represented one of the most valuable fresh water resources in North America. They contain more than one-fifth of the world’s supply of fresh surface water, and the vast size is easily visible from space. From Native American hunting routes to French fur-trade exploration to influential battles in the War of 1812, the Lakes have proved a key platform for numerous historical events that shaped the development of the country.
Uniquely, these bodies of water served as the gateway to connect the booming production of an expanding population in the Midwest from 1825 to 1925. During this time, a broad range of wooden, sailing, and steam-powered ships trekked across the lakes, carrying coal, grain, and passengers. Due to unpredictable weather conditions, fire, ice, high-traffic areas, and an ever-increasing pressure to meet shipping quotas, hundreds of ships were lost in collisions and accidents. These incidents have earned this period the nickname “Shipwreck Century.” Today, the history of the “Shipwreck Century” is presented at Thunder Bay National Marine Sanctuary’s visitor’s center, the Great Lakes Maritime Heritage Center, in Alpena, Michigan.
Thunder Bay is located in Lake Huron, near one of the most historically dangerous areas of navigation in the Great Lakes. The sanctuary covers 4,300 square miles. In this area, over 200 shipwrecks are known to exist, and 92 have been discovered and accurately charted. The staff provides continual archaeological monitoring to ensure the preservation of the sites.
Much of this archaeological work is completed aboard research vessel (RV) Storm. Storm is operated by the NOAA Great Lakes Environmental Research Laboratory (GLERL) and is dedicated to supporting Thunder Bay National Marine Sanctuary. Storm is suited for a diverse range of projects and is equipped with multibeam and side scan sonar for survey projects, compact crane for using remotely operated underwater vehicles, and drop-down transom for handling diving equipment. Additionally, her use of B100 fuel – engine and hydraulic oil manufactured from vegetable oils – and redesign with recycled materials qualify her as one of NOAA’s “green ships.”
Traditionally, the survey systems on Storm have been primarily used to provide accurate locations and high-resolution acoustic imagery of shipwrecks. Using these positions and contextual images, teams of Thunder Bay NMS archaeologists can complete dives to see the submerged cultural resources that lie beneath the surface. They share that information with the public at the Great Lakes Maritime Heritage Center.
A side scan sonar provided this acoustic image of W.C. Franz shipwreck.
With recent increases in multibeam and side scan sonar proficiencies, the sanctuary has started a new collaboration with the Office of Coast Survey. This summer, Coast Survey physical scientist Tyanne Faulkes and Ensign Max Andersen assisted Capt. Travis Smith and maritime archaeologists John Bright and Phil Hartmeyer in a new project. The team was tasked with surveying two unique sites: an Air Force and Air National Guard live-fire testing range, and a high-traffic area that needed updated navigational charts. The teams used RV Storm as a “vessel of opportunity” (a vessel not normally used for charting surveys) to conduct surveys to charting specifications. As such, some of Storm’s survey equipment needed to be “tuned” to meet those stringent hydrographic requirements. After some trial and error, Storm’s Applanix POSMV, Reson 8101, Klein 3000, Castaway CTD, Hypack 2016 machine were operational and ready for data acquisition.
NOAA marine archaeologist Phil Hartmeyer acquired survey data for the project.
The survey operations were a tremendous success. Throughout the month of August, Storm completed a series of acquisition voyages – as weather permitted – including a 36-hour operation on August 17 and 18. They acquired charting data covering 28 square nautical miles, along 418 linear nautical miles.
Projects like this show the great gains for the scientific community when different partners collaborate. We are looking forward to using more vessels of opportunity to expand on nautical chart updates in the Great Lakes region.
The two project survey areas for chart updates are shown by the colored bathymetry. The area on the right (in blue and green) was surveyed in response to a military request.
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.
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.
Coast Survey’s Navigation Response Team 4 is conducting a year-long survey of the sea floor in the Port of Houston and Galveston Bay navigational areas, re-measuring ocean depths and searching for dangers to navigation. Coast Survey will use the data to update future nautical charts to help mariners protect lives and increase shipping efficiencies. Recently, the team also found an opportunity where they could support marine archeological preservation.
Last week, the navigation team worked with federal and state partners who help us understand the rich history – and the secrets of human sorrows – lying on the seafloor. In collaboration with NOAA’s Flower Garden Banks National Marine Sanctuary and the Texas Historical Commission’s Marine Archeology Division, the navigation response team — with the State Marine Archeologist onboard — re-mapped the location of two historically significant wrecks. (Some of the data was collected under an antiquities permit, as Texas requires for investigating historic shipwrecks in state waters.)
“With the often-shifting sediment around here, there are periods of covering and uncovering, so archeologists like to periodically map historically significant wrecks to see what’s changed,” explained Nick Forfinski, the navigation response team’s leader. “We were ‘in the neighborhood,’ surveying for maritime commerce, and we were able to obtain up-to-date images of the wrecks while we were here.”
The steamship City of Waco is one of the historical wrecks that Forfinski’s crew was asked to survey. The steamship burst into flames and sank on Nov. 8, 1875, and 56 people died. The sunken ship was ordered to be demolished in 1900, to protect navigation in the area.
“The collaboration between NOAA experts and the Texas Historical Commission brings a unique combination of expertise and resources to learning more about the hidden history in the Gulf of Mexico,” said Texas State Archeologist Pat Mercado-Allinger. “We are grateful to the NOAA Team for this opportunity to remap this historically important shipwreck.”
Forfinski’s team captured some fascinating images of the City of Waco, created from data they gathered during last week’s hydrographic survey.
This image was created from data acquired by NRT4’s multibeam echo sounder. NOAA hydrographic survey units use multibeam echo sounder systems to acquire full (and partial) bottom bathymetric coverage, to measure depths over critical items such as wrecks, obstructions, and dangers-to-navigation, and for general object detection.
This image was created from data acquired by NRT4’s side scan sonar. A side scan creates a “picture” of the ocean bottom. For example, objects that protrude from the bottom create a light area (strong return) and shadows from these objects are dark areas (little or no return), or vice versa, depending on operator preference.
Using hydrographic surveys for multiple purposes, like “piggybacking” wreck mapping on to a navigation safety project, makes for smart resource sharing. It positions America for the future while helping to preserve its past.