Skip to content | Skip to institutional links

Common menu bar links

Liens institutionnels

Audiences

Activities

Resources

Transparency

Public Safety From Space: Frazil Ice & Sea Ice Jams in The St. Lawrence River

Government Related Initiatives Program (GRIP)

About GRIP Thematic Areas Lead Departments Events Contact Home

February, 2009

A variety of factors can cause emergencies, such as natural disasters, industrial accidents, terrorism and computer viruses. Whatever the cause, the Government of Canada works to reduce their impact. The ultimate purpose of emergency management is to save lives, preserve the environment and protect property and the economy. In January 2009, the St. Lawrence River Valley experienced extremely cold temperatures, which created severe emergency events, such as frazil, floods and ships jammed in the ice.

Frazil Monitoring

Frazil is a collection of loose randomly oriented needle-shaped ice crystals in water, formed in open, turbulent, supercooled waters. Multiple flooding alerts have been issued by municipalities and emergency organizations, particularly for "Rivière-des-milles-iles" and "Rivières des Prairies" in Montreal region.

Frazil in formation and a frazil ice cover (source: INRS-ETE)

Earth Observation (EO) satellites are key resources in a variety of disaster management scenarios. In the past, the data has been used effectively in floods/frazil and other natural or technological disasters. The Canadian Space Agency (CSA) RADARSAT program was born out the need for effective monitoring of Canada's icy waters. EO satellites, such as RADARSAT-2, have an advantage over aerial surveillance missions. Radar satellites operate day and night in all weather conditions, and provide timely coverage of vast areas. Some RADARSAT-2 capabilities that benefit river-ice applications are the multi-polarization options that improve ice-edge detection, ice-type discrimination, and ice topography and structure information.

Following a request from the Ministère de la Sécurité publique du Québec (MSP) to Public Safety Canada, the MSP is now using RADARSAT-2 imagery to better monitor and manage frazil, ice jam and flood events. RADARSAT-2 data have been acquired on January 8, 14, 22 and 25. INRS-ETE has developed the algorithms for the generation of river ice maps. Technology has been developed in the FRAZIL project, supported by GEOIDE RCE & through past CSA Earth Observation Applications and Utilizations Division projects. In January 2009, INRS-ETE has generated imagery ice products in the context of a technology transfer to MSP.

St. Lawrence River ice map (Rivière des Parairies region, Montréal) from January 8 based on RADARSAT-2 imagery (source: MSP, MRNF, DGE, MAMROT)

Example of ice products, based on RADARSAT imagery (source: INRS-ETE)

Frazil and river ice classification over Lac des Deux Montagnes and Lac St-Louis (Montreal), based on RADARSAT-2 imagery (source: INRS-ETE)

Ships Trapped on Icy St. Lawrence River

Every year, cruise ships carrying thousands of passengers navigate in Canadian waters, especially on the St. Lawrence River. Navigation in heavy icy waters requires a careful understanding of ice conditions and depends on the provision of ice information. The cruise ship CTMA-Vacancier, and on board 150 participants of La Traversée de la Gaspésie 2009, a nordic ski initiative, became stuck in the heavy ice for multiple days near Matane, Quebec. Other ships, like the Georges-Alexandre-Lebel and Camille-Rioux ferryboats, were also stock in the ice jam. The Coast Guard icebreaker Terry-Fox was deployed to rescue ships on icy St. Lawrence River.

CTMA-Vacancier trapped in the ice and the Terry-Fox icebreaker (source: Radio-Canada)

RADARSAT-2 images below show the ships trapped in the ice near Matane. Ships can be seen on the image, as bright white features. These images have been provided to the CSA Earth Observation Applications and Utilizations Division by the Canadian Ice Service (CIS). CIS is the leading authority for information about ice in Canada's navigable waters. CIS has been an active participant in the CSA Radarsat program since its inception, and throughout the research, development, and operational phases. The CIS now critically relies on Radarsat to provide operational ice reconnaissance over a seasonal ice cover of approximately 2 million km².