USING AIRBORNE THERMAL INFRARED IMAGERY FOR MAPPING LOCATIONS OF SUBMARINE GROUNDWATER DISCHARGE

Airborne thermal infrared (TIR) imagery can be used to map point-source and diffuse submarine groundwater discharge (SGD) at regional and local scales. TIR imaging creates instant maps of discharge zones along the shoreline that can be used to better constrain field-based operations. For large scale studies, satellite imagery may be adequate for analyses whereas smaller scale studies requiring high spatial resolution should use airborne imagery. TIR investigations likely provide a conservative estimate of the areal extent of SGD and may not be able to capture seepage that exists further offshore. This methodology was applied along the north shore of Long Island, NY, where SGD occurs as predominantly diffuse seepage. The areal distribution of SGD, as well as the temperature difference between nearshore water and ambient surface waters, may be useful parameters for remotely estimating seepage rates.