drift card

drift card

[′drift ‚kärd]
(oceanography)
A card, such as is used in a drift bottle, encased in a buoyant, waterproof envelope and released in the same manner as a drift bottle.
References in periodicals archive ?
In August, 400 plywood drift cards stamped with ''This could be oil" were thrown into the Fraser River to demonstrate how far oil might travel if it spilled out of Kinder Morgan's Trans Mountain pipeline, and within 50 minutes the cards had travelled three and a half kilometres downstream.
Drift cards trajectory released at Banco Chinchorro, Quintana Roo
One thousand drift cards were released in November 1994 and October 1996 in order to determine the direction and speed of the surface currents in southern Quintana Roo, and to relate them to larvae transport.