Detection of coastal spring and submarine groundwater discharge using thermal remote sensing and field investigation

Submarine groundwater discharge (SGD) has been recognized to be a potentially significant pathway of inland groundwater to oceans. SGD could deliver significant amounts of freshwater and dissolved chemical species to the coastal zone, which could cause unexpected eutrophication and other environmental changes. In this study, airborne thermal remote sensing techniques combined with geochemical tracing and GIS were used to detect coastal spring and submarine groundwater discharge in Jeju Island, South Korea. Temperature profiles of seawater at nearshore zones were obtained and compared with remote sensing data. Surface seawater temperature anomalies obtained from airborne remote sensing were used to detect cold water plumes which were associated with inland groundwater discharges. Seepage measurements and Rn isotope analyses were applied to verify the presence of SGD. This work will provide effective methods to detect coastal spring and submarine groundwater discharge on a regional scale.