Zanclean flood

Artistic interpretation of the flooding of the Mediterranean through the Gibraltar Strait (A) and the Strait of Sicily (F) about 5.3 million years ago
Artistic interpretation of the flooding of the Mediterranean through the Gibraltar Strait
Computer simulation of the flooding of the Mediterranean through the Gibraltar Strait, with the vertical scale exaggerated for better visualization. The view in this image is from the southwest of Gibraltar, with the future Iberian Peninsula in the center-left, northwest Africa in the lower-right, and the British Isles in the upper-left corner.

The Zanclean flood or Zanclean deluge is theorized to have refilled the Mediterranean Sea 5.33 million years ago.[1] This flooding ended the Messinian salinity crisis and reconnected the Mediterranean Sea to the Atlantic Ocean, although it is possible that even before the flood there were partial connections to the Atlantic Ocean.[2] The re-connection marks the beginning of the Zanclean age which is the name given to the earliest age on the geologic time scale of the Pliocene.

According to this model, water from the Atlantic Ocean refilled the dried-up basin through the modern-day Strait of Gibraltar. Ninety percent of the Mediterranean Basin flooding occurred abruptly during a period estimated to have been between several months and two years, following low water discharges that could have lasted for several thousand years.[3] Sea level rise in the basin may have reached rates at times greater than ten metres per day (thirty feet per day). Based on the erosion features preserved until modern times under the Pliocene sediment, Garcia-Castellanos et al. estimate that water rushed down a drop of more than 1,000 metres (3,000 ft) with a maximum discharge of about 100 million cubic metres per second (3.5 billion cubic feet per second), about 1,000 times that of the present-day Amazon River. Studies of the underground structures at the Gibraltar Strait show that the flooding channel descended gradually toward the bottom of the basin rather than forming a steep waterfall.[4]

  1. ^ Blanc, P.-L. (2002). "The opening of the Plio-Quaternary Gibraltar Strait: assessing the size of a cataclysm". Geodinamica Acta. 15 (5–6): 303–317. Bibcode:2002GeoAc..15..303B. doi:10.1016/S0985-3111(02)01095-1.
  2. ^ Efe, Recep (17 March 2014). Environment and Ecology in the Mediterranean Region II. Cambridge Scholars Publishing. p. 11. ISBN 978-1-4438-5773-4.
  3. ^ Garcia-Castellanos et al. 2009.
  4. ^ Garcia-Castellanos et al. 2009, p. 778.