*That's pretty strange by traditional standards of explaining geophysics.
Seas and lakes of magma affect one another, who knew
(...)
It is known that the Strait of Gibraltar was temporarily shut during the Messinian Era (more precisely, from 5.96 to 5.33 million years ago) and that the Mediterranean Sea was isolated from the Atlantic. In fact, as far back as the 1970s, scientists have found layers of salt several hundred metres thick on the seabed. The only explanation is that there was very limited connection between the Mediterranean and the Atlantic. The scientists also discovered huge underwater canyons dating back to the same period, hollowed out by rivers running over land that is now submerged, suggesting that the sea level was much lower at the time. This also points to the massive drying up of the Mediterranean with enormous geographical and climatic disruption across the entire basin. This hypothesis, however, continues to be a source of debate.
Nevertheless, a team of UNIGE-led geologists has provided new evidence of the Mediterranean's drying up and the forcing of surface processes on magmatic activity. "We understand that what happens at the Earth's surface, such as a sudden sea level lowering, causes the pressure to change at depth and has an effect on magma production," says Pietro Sternai, researcher in the Department of Earth Sciences in UNIGE's Science Faculty. Given that the salinity crisis was capable of generating these changes in pressure, the geologists, working on the hypothesis that the Mediterranean dried out, studied the changes in volcanic activity during this period.
When a volcano erupts, the magma cools on the Earth's surface and the minerals crystallise. Based on these silent witnesses of volcanic activity, the scientists were able to establish that there were 13 eruptions around the Mediterranean between 5.9 and 5.3 million years ago. This is over twice the average activity, which is around 4.5 eruptions over a longer time length encompassing the salinity crisis. Why is the figure so high? "The single logical explanation," suggests Sternai, "is the hypothesis that the sea dried out, since this is the only event powerful enough to alter the Earth's pressure and magmatic production over the entire Mediterranean." (...)
Read more at: https://phys.org/news/2017-09-geologists-mediterranean-sea-million-years.html#jCp
