Submarine springs and coastal karst aquifers: A review

• Published in: Journal of hydrology (Amsterdam) Vol. 339; no. 1; pp. 79 - 92
• Main Authors: Fleury, Perrine, Bakalowicz, Michel, de Marsily, Ghislain
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 10-06-2007; Elsevier Science; Elsevier
• Subjects: Coastal aquifers; Earth Sciences; Earth, ocean, space; Exact sciences and technology; Hydrology. Hydrogeology; Karst; Marine; Messinian salinity crisis; Salt-water intrusion; Sciences of the Universe; Submarine springs; MED, Western Mediterranean; MED; Submarine springs; Messinian salinity crisis; Salt-water intrusion; Karst; Coastal aquifers; Neogene; submarine springs; surveys; upper Tertiary; drainage patterns; exploitation; currents; hydraulics; water resources; aquifers; discharge; Cenozoic; salinity; density; Tertiary; salt-water intrusion; Messinian; classification; karst; karstification; glaciation; upper Miocene; decision making; Miocene; Phanerozoic; sea level
• ISSN: 0022-1694; 1879-2707
• DOI: 10.1016/j.jhydrol.2007.03.009

This article reports on current knowledge of coastal karst aquifers, in which conduit flow is dominant, and its aim is to characterise the functioning of these systems which are closely linked to the sea. First, earlier and recent studies of these aquifers are discussed. On the basis of their findings, it can be shown that two essential mechanisms are involved in the functioning of these systems, i.e., aquifer discharge through submarine springs and saline intrusion through conduits open to the sea.
Then, the conditions that give rise to these aquifers are described and particular emphasis is placed on the influence of deep karstification when the sea level falls. The base-level variations are attributed to the glaciations or, in the specific case of the Mediterranean, to the salinity crisis in the Messinian period. It is this inherited structure, sometimes containing very deep conduits below sea level, that today conditions the aquifer flow. The flow in the conduits open to the sea depends on the hydraulic head gradient between the aquifer and the sea and is therefore a function of the water density and head losses in the aquifer.
This survey of coastal karst aquifers has revealed some common characteristics that show the development and/or functional capacity of their karstic drainage networks. A classification of such systems into three categories is proposed with the aim of assisting in the decision-making concerning potential exploitation of water resources in coastal regions.