The phenomenon of warm waters in
Las Grutas
The warmth and transparency of waters of the San Matías Gulf, and in particular of the Bay of San Antonio, are due to the combination of oceanographic and atmospheric factors, with the peculiar geographic conformation of the coastal zone.
The amplitude of the tides, the system of circulation of the coastal currents, the high temperatures of the summer and the pluvial precipitation shortage, are factors that contribute to this phenomenon.
The tides are cyclical movements that the level of the sea experiences, and they are very pronounced in the gulf. The tides experience daily changes in the level of the sea that oscillate between the 6 and 9 meters.
This difference of level determines that the totality of the surface of the Bay of San Antonio is flooded twice a day and also is dry many hours a day.
In the hours of low tide, the solar radiation warms up the inter tidal sand plains of the bay, also producing an increase in the temperature of the water buried under the sand.
This accumulated heat soon is transferred by convection to the mass of water that floods the Bay of San Antonio in the hours of high tide, causing an increase in the average temperature of the water.
The high temperature in the months of summer generates greater evaporation of the water that enters the Bay of San Antonio, which is translated in a greater accumulation of salts in the mass of present water in the system.
For that reason this beaches are unique: they are the warm water beaches in the coast of Argentina.