A massive flood called the Zanclean Flood ended the Messinian salinity crisis that lasted from 5.97 million to 5.33 million years ago, according to a new study led by the Monterey Bay Aquarium Research Institute (MBARI).
One of the scenarios being discussed for ending the Messinian Salinity Crisis 5.33 million years ago is the catastrophic backfilling of the Mediterranean Sea by the Zanclean Flood. Micallef others. They present clear onshore and offshore evidence that this deluge spilled over a shallow marine corridor in southeastern Sicily into the nearby underwater Noto Gorge. This aerial photo shows a ridge eroded by a major flood, located northeast of Masseria del Volpe, in southeastern Sicily. Image credit: Kevin Sciberras and Neil Petroni.
“The Zanclean Flood is an awe-inspiring natural phenomenon, with flows and velocities that seem dwarfed by any other known flood in Earth’s history,” said the study’s lead author, C.A. said Dr. Aaron Micallef, a research scientist at the Monterey Bay Aquarium Research Institute.
“Our study provides the most convincing evidence yet of this unusual event.”
During the Messinian salinity crisis, the Mediterranean Sea was isolated from the Atlantic Ocean and evaporated, creating vast salt deposits that transformed the region’s landscape.
Scientists have long believed that this dry period would gradually end and that the Mediterranean Sea would be reclaimed over 10,000 years.
However, the discovery in 2009 of an eroded channel stretching from the Gulf of Cadiz to the Alboran Sea called this idea into question.
The discovery points to a single major flooding event lasting between two and 16 years, which became known as the Zanclean Flood.
Estimates indicate that the outflow of this megaflood was between 68 and 100 Sverdraps (Sv), where 1 sievert is equivalent to 1 million cubic meters per second.
In their research, Dr. Micallef and his colleagues combined newly discovered geological features with geophysical data and numerical modeling to provide the most comprehensive picture of the megaflood to date. did.
The researchers investigated more than 300 asymmetric streamlined ridges in the corridor across the Sicilian Sil, a submerged land bridge that once separated the western and eastern Mediterranean basins.
“The morphology of these ridges corresponds to erosion by large-scale turbulence, mainly in a north-easterly direction,” said Professor Paul Carling from the University of Southampton.
“They reveal the immense power of the Zanclean Flood and how it changed the landscape and left a lasting mark on the geological record.”
Scientists sampled the ridge and found that it was overlain by a layer of rock debris containing material eroded from the sides of the ridge and surrounding areas. This indicates that it was deposited there rapidly and with great force.
This layer lies right on the boundary between the Messinian and Zanclean periods, where the Great Flood is thought to have occurred.
Using seismic reflection data, a type of geological ultrasound that allows scientists to see layers of rock and sediment beneath the Earth’s surface, the authors found a “W-shaped” shape on the continental shelf east of Sicily’s Sill. discovered a waterway.
This channel, dug into the ocean floor, connects the ridge to the Noto Gorge, a deep underwater canyon located in the eastern Mediterranean.
The shape and location of the channel suggest that it functioned like a giant funnel.
When the mega-flood flowed into Sicily’s Sill, this channel is thought to have carried the water towards the Noto Valley and into the eastern Mediterranean.
The research team developed a computer model of the flood to simulate how the water behaved.
The model shows that floodwaters change direction and increase their strength over time, reaching speeds of up to 32 meters per second (72 miles per hour), carving deeper channels, eroding more material, and increasing their length. This suggests that they may have been transported over long distances.
“These discoveries not only reveal a critical moment in Earth’s geological history, but also prove that landforms persist for five million years,” Dr. Micallef said.
“This opens the door to further research on the Mediterranean coast.”
of study Published in a magazine Communication Earth and Environment.
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A. Micallef others. 2024. Land-to-sea indicators of the Zanclean Flood. common global environment 5,794;doi: 10.1038/s43247-024-01972-w
Source: www.sci.news
