Hydrography Playing a Key Role in Underwater Archaeology
Hydrography helps to add to our knowledge about the sea floor by establishing detailed bathymetry (water depth) as well as identifying any obstacles or other objects resting there. This work is performed using modern tools such as high-resolution, multi-beam echo sounders and side-scan sonar combined with a precise positioning system.
The sea floor is home to numerous shipwrecks, some of which also have particular historical importance. Their discovery not only provides a glimpse into bygone days of people’s local seafaring past but also has a human component, since these sites deserve the same respect as any cemetery.
The discovery of certain historic shipwrecks draws major media attention, such as that of the Franklin expedition in the Arctic. Following the discovery of the HMS Erebus in September 2014, the wreck of the second vessel, the HMS Terror, was also very recently located.
Public interest is also stimulated and maintained through several television series, including the French-language Chasseur d’épaves hosted by Samuel Côté. Over the years, the hydrographers at the Canadian Hydrographic Service have offered their cooperation to that series, and Mr. Côté has come to consult our archives and sounding data a number of times.
However, the main responsibility of hydrographers is not looking for shipwrecks but rather ensuring safe navigation. Their work does involve detailed detection of obstacles, many of which are in fact wreckage. Our hydrographers watch closely for irregularities and forward information on where appropriate to the receiver of wrecks responsible for managing wreck sites.
For example, while surveying the waters off of Île d’Orléans this past June, the hydrography crew aboard the CCGS Frederick G. Creed came across an unusual shape. Guided by their expertise, they decided to make another pass over this obstacle to view it in greater detail. In the resulting image, they could clearly make out the outline of a well-preserved wreck. After transmitting the information to the receiver of wrecks, they contacted Samuel Côté, who had been searching that area for years for the wreck of the SS Christine.
A video crew from the popular series Chasseurs d’épaves came to meet with the hydrographers to record footage and interview some of the crewmembers.
Broadcasting this information on television helps people to see a part of what hydrographers do. And who knows: maybe it will capture the interest of young people seeking a career in a discipline where much remains to be explored.
Robert Dorais
Science
Image of the wreck of the SS Christine from the multibeam acoustic data
