100 years yesterday, the RMS Titanic struck an iceberg while crossing the North Atlantic and sank, killing over 1500 passengers and crew. 

Today, thousands of boats cross the same iceberg-ridden path with no loss of life. Intelligence about conditions has obviously gotten a lot better but improvements sometimes need a catalyst- and the Titanic was it. Rather than rely on a guy in a lookout tower, the Titanic got us the International Convention for the Safety of Life at Sea and the International Ice Patrol (IIP).  The IIP first used marine vessels to perform routine ice patrols and warn vessels but switched to aerial surveillance after World War II. Aerial surveillance is still the primary ice reconnaissance method but IIP wants to replace expensive ice flights and has been looking to satellite observations as the successor technology.  

They monitor icebergs and establish an iceberg danger area based on observations that are fed into drift and melt models and, to-date, no vessel that has heeded the Ice Patrol’s published ‘iceberg limit’ has collided with an iceberg. That's a good result, since at any time there may be tens to hundreds of thousands of icebergs in Arctic waters. Their primary challenge is to the  icebergs that will drift south towards shipping lanes in the North Atlantic between Europe and the major ports of the United States and Canada.  They can't be too cautious or nothing would ever get shipped but too careless and disaster can happen.

Baltic Sea shipping routes and ice thickness sees more than 2000 large vessels every day, the busiest ice-covered sea in the world. Credits: ESA/DLR

The use of satellites for iceberg surveillance first caught the attention of scientists in 1992 when ESA’s ERS-1 satellite, carrying the synthetic aperture radar, was launched. Radars on satellites are particularly suited to iceberg monitoring because they can acquire images through clouds and darkness. The initiation of ESA’s Global Monitoring for Environmental Security (GMES) program allowed wide-scale operational demonstrations to begin.

Ice Patrol’s Area Of Operations
The International Ice Patrol’s Area Of Operations in yellow from 40ºN to 50ºN, and 39ºW to 57ºW. The 48ºNh latitude line is drawn in purple within the Ice Patrol AOR. The transatlantic shipping lanes from Europe to North America are in red. Typical iceberg paths and distribution within the AOR are represented by numerous white triangles along the 200 m bathymetry from Greenland to the Grand Banks of Newfoundland. The position of the 1912 Titanic sinking is represented by a white asterisk at the tail of Grand Banks near the bottom of the Ice Patrol AOR. Credits: IIP

Discriminating between icebergs and vessels based solely on the radar images remains a challenge, but C-CORE, IIP and others are working to improve the reliability of this process.  Under GMES, the Sentinel-1 constellation envisaged for launch in 2013 will provide complete coverage of the Arctic every 24 hours and therefore play an important role for iceberg monitoring. Data from the current CryoSat-2 and forthcoming Sentinel-3 missions will complement this by providing information on extreme sea-ice features.