Aerial Photointerpretation of a Small Ice Jam

• Main Author: DenHartog, Stephen L
• Other Authors: COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
• Format: Text
• Language: English
• Published: 1977
• Subjects: Cartography and Aerial Photography; Snow; Ice and Permafrost; *PACK ICE; *PHOTOINTERPRETATION; AERIAL PHOTOGRAPHS; DRIFT; DYNAMICS; ICE; ICE BREAKUP; ICE REPORTING; MOTION; RIVER CURRENTS; RIVERS; SEASONAL VARIATIONS; SLOPE; VELOCITY; *ICE JAMS; PEMIGEWASETT RIVER; Ice; permafrost
• Online Access: http://www.dtic.mil/docs/citations/ADA045870; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA045870

Aerial photos of a small ice jam on the Pemigewasett River near Plymouth, New Hampshire, were taken three days after the jam and compared with photos taken after the ice went out. The winter photos show a marked and sudden decrease in floe size apparently indicative of faster and longer movement of the ice. The spring photos show a number of shallows and obstructions that apparently had no effect on the ice movement. It is concluded that this jam was caused by a change in slope and subsequent reduction in velocity.