Collection search - Ice Charts of the St. Lawrence Seaway, Atmospheric Environment Service, Environment Canada [cartographic material]

This accession consists of records created by the Atmospheric Environment Service, and maintained by Environment Canada. The records consist of charts of the St. Lawrence Seaway with hand-drawn colourations illustrating ice locations and conditions, specifically indicating the presence of fast ice and open water. The date range for these charts is as follows: Box 1, 1970-12-10 to 1973-01-31; Box 2, 1973-02-01 to 1974-04-22; Box 3, 1974-04-04 to 1974-04-04; Box 4, 1976-12-03 to 1978-03-10; Box 5, 1978-03-11 to 1979-03-31; Box 6, 1979-04-01 to 1987-03-18; Box 7, 1989-12-04 to 1995-03-20.