On atoll islands, the fresh water lens (FWL) constitutes, for island population, a very important resource various usages. Its shape and thickness highly depend on underground characteristics of several rock formations which constitute island: upper Holocene sediments lower Pleistocene limestone rocks separated by Unconformity. In this study, simple investigation methods were applied Pacific Ra...

Saltwater intrusion is an ideal target for mapping with airborne electromagnetic techniques because of the high electrical conductivity of saline water and its contrast with that of freshwater. Using electromagnetic sensors to measure the electromagnetic response of the ground at several frequencies, information from various depths is obtained. The electromagnetic response is then converted to ...

Most cave and karst ecosystems are believed to be dependent on an influx of allochthonous organic carbon. Although microbes are largely responsible for the fate of dissolved organic matter (DOM) in karst, the role of microbes in chemosynthetic (autochthonous) production and processing of DOM has received limited attention. Chromophoric dissolved organic matter (CDOM) is the fraction of DOM that...

Saltwater intrusion into the coastal aquifer, a phenomenon brought by the flow of seawater into freshwater aquifers originally caused by groundwater extraction near the coast, has long been recognised as a major concern around the world. In this study, we employed geophysical and geochemical techniques to map and provide evidences that the coastal aquifers in the study area have been intruded b...

Nitrous oxide (N2O) has 265 times greater greenhouse potential than carbon dioxide and its atmospheric concentration has increased by about 20% since industrialization; however, N2O production and emissions from aquatic systems are poorly constrained. To evaluate N2O fluxes associated with meteoric groundwater discharge to coastal zones, we measured N2O concentrations in May and October 2011 fr...