Earth is lucky to have us. Otherwise…
Oh! The things we’ve missed seeing, the vicissitudes of air, sea, and land. Take ancient floods, for example. Go back about 5.5 million years to the ancient Mediterranean Sea. Oh! Wait! There wasn’t much of a sea at that time, termed Zanclean. Seems that the Med had pretty much been cut off from the Atlantic back then, allowing evaporation to do its work, drying up much of the water in the huge hole and allowing salts to accumulate. It was the Messinian Salinity Crisis. And then the water poured back in. Lots of water and very fast. Think Niagara and Victoria are wondrous? Think again. Think that the Amazon sends lots of water through its channel? Think again.
Marine geologists have known about the “salinity crisis” for decades, but a new study adds to their perception of the reflooding episode and reveals how little we truly know about the past and events that helped to shape the present. Here’s the nutshell version. The Mediterranean Sea, as you know, is open to the Atlantic at the Strait of Gibralter, currently just about nine miles wide. The Camarinal Sill, which in some places lies only 100 meters below present sea level serves as a kind of dam with about a 100-meter drop in sea level. About five and a half million years ago, evaporites (salts) began to accumulate in both shallow and deep water, indicating evaporation (When salt water evaporates, it leaves behind its salts). It appears that the inflow from the Atlantic was cut off. According to research by a French team of researchers led by Georges Clauzon in the 1990s, there were two dessication events, one affecting shallow basins that occurred during a cooling world climate, and another that that occurred during a warming world climate during which sea level dropped enough to isolate the deeper basins. *
Today, the Mediterranean Sea is a sea, right? That means the water had to return, spilling in from the Atlantic and flowing in from encompassing rivers, such as the Nile (which also overlies a much deeper channel that it filled in as sea level rose). Anyway, for the Med to refill, there had to be a very large inflow. In a 2018 paper on that inflow as it cut canyons and laid down sediments, A. Micallef, Daniel Garcia-Castellanos, and others report that the inflow off the coast of Sicily, evidence supports a flood equal to 100 million cubic meters per second—a thousand times greater than the Amazon’s discharge.**
Why should you bother with such information, especially if you have no interest in marine geology, eustacy, or salt deposits on the bottom of a sea? Probably two reasons. First, the world climate obviously went through a dramatic change, enough to allow evaporation to lower the Mediterranean by more than a thousand meters (over 3,000 feet). That’s three-fifths of a mile of water over 2.5 million square kilometers (965,000 square miles). By comparison, California covers just over 400,000 square km, or about 150 thousand plus square miles. The Med lost lots of water; imagine a similar lowering of sea level today if you can. There's been no comparable event in your lifetime. Second, you live in a very small window of “earth time,” and you’ve missed all the wondrous changes and big events of the past. Imagine seeing that ancient flood as water spilled back into the Mediterranean. Think of one thousand Amazon Rivers discharging their water through a narrow opening not much wider than the current Amazon.
You’ve missed very big events that were probably instrumental to your being here. Extinctions, for example. Great swings in world climate. Tropical forest giving way to savanna and opening the way for bipedalism. Even great changes in atmospheric composition. Take oxygen levels as an example. Today, you breathe easily in a bath of air that is about 21% oxygen. That wasn’t always so, however. Go back a very long way, between 2.5 and four billion years ago, and free oxygen wasn’t readily available. Then there was a period called the Great Oxidation Event about 2.4 billion years ago, lasting about 350 million years. Microbes proliferated. Microbes abounded. And then. Big drop in O. Little critters dying off everywhere. A worldwide change in life. *** Of course, you’re not sympathetic. Microbes. Oooo! Yuck! Shudder to think of one-celled organisms making up the entire biosphere. But every event leads to another event, not in a straight-line causation, but in opportunities for other life-forms to rise. And so, oxygen levels once again began to rise, even if slowly, until they reached another high at the time of the dinosaurs just before their extinction. And, cut to the chase, here we are.
Climates come and go. Sea level falls and rises. Storms wreak havoc on life here and there, sometimes frequently, sometimes infrequently. Now add the human being into the equation. “The sky is falling; the sky is falling.” It’s our nature in general to panic and to believe all that occurs, occurs in our lifetimes. That we’ve seen the worst Mother Nature has to offer isn’t necessarily so, hurricanes, volcanic eruptions, and tsunamis notwithstanding. Ask those microbes that underwent a mass die-off 2 billion years ago. Ask the 95% of all species that died off during the Permian Extinction’s Great Dying. Ask the dinos at the end of the Cretaceous. Could things be worse than they are now? Obviously, yes.
So, now we’re worried about sea level rise. Or, maybe not. Didn’t I hear a former President say in a nomination victory speech that “this is the moment when the rise of the oceans began to slow and our planet began to heal….” **** That must really have been the moment. Really. That former President just bought a multimillion-dollar home and property on Martha’s Vineyard, one of the very seaside locations where sea level over the past two million years has been radically different, an island of shifting sands subject to the whims of Mother Nature that would have been submerged at times and high and dry at other times. Sea level rise? Problem solved. Mediterranean drying up and then reflooding? Problem solved. Extinctions? A thing of the past. As that President once said (on Super Tuesday), “We are the ones we’ve been waiting for. We are the change that we seek.” Seaside resort owners, rejoice. Seaside luxury home owners, too.
We were born too late to see the Great Oxidation Event and the subsequent extinction of the microbes, too late to witness the Great Dying, too late to see the dinosaurs kick the bucket, too late to see the ice cover much of the Northern Hemisphere, too late to see sea level 100 meters or more lower during the ice advances, and even more recently, too late to see the sea rise to levels above current eustacy, and much too late to see the Mediterranean Sea dry up and reflood. Lucky us. And lucky Earth. “We are the ones we’ve been waiting for,” and so have the realtors on Martha’s vineyard.
*Clauzon, Georges, et al., Alternate interpretation of the Messinian salinity crisis: Controversy resolved? Geology, April 1996. V 24, no. 4, p. 363-366.
**Micallef, Aaron, Angelo Camerlenghi, Daniel Garcia-Castellanos, Daniel Cunarro Otero, Mark-Andre Cutscher, Giovanni Barreca, Daniele Spatola, Loreno Facchin, Riccardo Geletti, Sebastian Krastel, Felix Gross, and Morelia Urlaub. Evidence of the Zanclean megaflood in the eastern Mediterranean Basin. Nature. Scientific Reports. 18 January 2018., 8:1078 | DOI:10.1038/s41598-018-19446-3 https://drive.google.com/file/d/18D4BOvzvJzecmWPfqD7kmNz9uMj4PG4s/view
The average discharge of the Amazon is over 200,000 cubic meters per second or over 7 million cubic feet per second.
***Hodegskiss, Malcolm S. W, Peter W. Crockford, Yongbo Peng, Boswell A. Wing, and Tristan J. Horner. A productivity collapse to end Earth’s Great Oxidation. PNAS August 27, 2019. vol. 116 no. 35 17207-17212. DOI:
https://doi.org/10.1073/pnas.1900325116
**** https://obamamessiah.blogspot.com/2008/06/this-was-moment-when-rise-of-oceans.html
Oh! The things we’ve missed seeing, the vicissitudes of air, sea, and land. Take ancient floods, for example. Go back about 5.5 million years to the ancient Mediterranean Sea. Oh! Wait! There wasn’t much of a sea at that time, termed Zanclean. Seems that the Med had pretty much been cut off from the Atlantic back then, allowing evaporation to do its work, drying up much of the water in the huge hole and allowing salts to accumulate. It was the Messinian Salinity Crisis. And then the water poured back in. Lots of water and very fast. Think Niagara and Victoria are wondrous? Think again. Think that the Amazon sends lots of water through its channel? Think again.
Marine geologists have known about the “salinity crisis” for decades, but a new study adds to their perception of the reflooding episode and reveals how little we truly know about the past and events that helped to shape the present. Here’s the nutshell version. The Mediterranean Sea, as you know, is open to the Atlantic at the Strait of Gibralter, currently just about nine miles wide. The Camarinal Sill, which in some places lies only 100 meters below present sea level serves as a kind of dam with about a 100-meter drop in sea level. About five and a half million years ago, evaporites (salts) began to accumulate in both shallow and deep water, indicating evaporation (When salt water evaporates, it leaves behind its salts). It appears that the inflow from the Atlantic was cut off. According to research by a French team of researchers led by Georges Clauzon in the 1990s, there were two dessication events, one affecting shallow basins that occurred during a cooling world climate, and another that that occurred during a warming world climate during which sea level dropped enough to isolate the deeper basins. *
Today, the Mediterranean Sea is a sea, right? That means the water had to return, spilling in from the Atlantic and flowing in from encompassing rivers, such as the Nile (which also overlies a much deeper channel that it filled in as sea level rose). Anyway, for the Med to refill, there had to be a very large inflow. In a 2018 paper on that inflow as it cut canyons and laid down sediments, A. Micallef, Daniel Garcia-Castellanos, and others report that the inflow off the coast of Sicily, evidence supports a flood equal to 100 million cubic meters per second—a thousand times greater than the Amazon’s discharge.**
Why should you bother with such information, especially if you have no interest in marine geology, eustacy, or salt deposits on the bottom of a sea? Probably two reasons. First, the world climate obviously went through a dramatic change, enough to allow evaporation to lower the Mediterranean by more than a thousand meters (over 3,000 feet). That’s three-fifths of a mile of water over 2.5 million square kilometers (965,000 square miles). By comparison, California covers just over 400,000 square km, or about 150 thousand plus square miles. The Med lost lots of water; imagine a similar lowering of sea level today if you can. There's been no comparable event in your lifetime. Second, you live in a very small window of “earth time,” and you’ve missed all the wondrous changes and big events of the past. Imagine seeing that ancient flood as water spilled back into the Mediterranean. Think of one thousand Amazon Rivers discharging their water through a narrow opening not much wider than the current Amazon.
You’ve missed very big events that were probably instrumental to your being here. Extinctions, for example. Great swings in world climate. Tropical forest giving way to savanna and opening the way for bipedalism. Even great changes in atmospheric composition. Take oxygen levels as an example. Today, you breathe easily in a bath of air that is about 21% oxygen. That wasn’t always so, however. Go back a very long way, between 2.5 and four billion years ago, and free oxygen wasn’t readily available. Then there was a period called the Great Oxidation Event about 2.4 billion years ago, lasting about 350 million years. Microbes proliferated. Microbes abounded. And then. Big drop in O. Little critters dying off everywhere. A worldwide change in life. *** Of course, you’re not sympathetic. Microbes. Oooo! Yuck! Shudder to think of one-celled organisms making up the entire biosphere. But every event leads to another event, not in a straight-line causation, but in opportunities for other life-forms to rise. And so, oxygen levels once again began to rise, even if slowly, until they reached another high at the time of the dinosaurs just before their extinction. And, cut to the chase, here we are.
Climates come and go. Sea level falls and rises. Storms wreak havoc on life here and there, sometimes frequently, sometimes infrequently. Now add the human being into the equation. “The sky is falling; the sky is falling.” It’s our nature in general to panic and to believe all that occurs, occurs in our lifetimes. That we’ve seen the worst Mother Nature has to offer isn’t necessarily so, hurricanes, volcanic eruptions, and tsunamis notwithstanding. Ask those microbes that underwent a mass die-off 2 billion years ago. Ask the 95% of all species that died off during the Permian Extinction’s Great Dying. Ask the dinos at the end of the Cretaceous. Could things be worse than they are now? Obviously, yes.
So, now we’re worried about sea level rise. Or, maybe not. Didn’t I hear a former President say in a nomination victory speech that “this is the moment when the rise of the oceans began to slow and our planet began to heal….” **** That must really have been the moment. Really. That former President just bought a multimillion-dollar home and property on Martha’s Vineyard, one of the very seaside locations where sea level over the past two million years has been radically different, an island of shifting sands subject to the whims of Mother Nature that would have been submerged at times and high and dry at other times. Sea level rise? Problem solved. Mediterranean drying up and then reflooding? Problem solved. Extinctions? A thing of the past. As that President once said (on Super Tuesday), “We are the ones we’ve been waiting for. We are the change that we seek.” Seaside resort owners, rejoice. Seaside luxury home owners, too.
We were born too late to see the Great Oxidation Event and the subsequent extinction of the microbes, too late to witness the Great Dying, too late to see the dinosaurs kick the bucket, too late to see the ice cover much of the Northern Hemisphere, too late to see sea level 100 meters or more lower during the ice advances, and even more recently, too late to see the sea rise to levels above current eustacy, and much too late to see the Mediterranean Sea dry up and reflood. Lucky us. And lucky Earth. “We are the ones we’ve been waiting for,” and so have the realtors on Martha’s vineyard.
*Clauzon, Georges, et al., Alternate interpretation of the Messinian salinity crisis: Controversy resolved? Geology, April 1996. V 24, no. 4, p. 363-366.
**Micallef, Aaron, Angelo Camerlenghi, Daniel Garcia-Castellanos, Daniel Cunarro Otero, Mark-Andre Cutscher, Giovanni Barreca, Daniele Spatola, Loreno Facchin, Riccardo Geletti, Sebastian Krastel, Felix Gross, and Morelia Urlaub. Evidence of the Zanclean megaflood in the eastern Mediterranean Basin. Nature. Scientific Reports. 18 January 2018., 8:1078 | DOI:10.1038/s41598-018-19446-3 https://drive.google.com/file/d/18D4BOvzvJzecmWPfqD7kmNz9uMj4PG4s/view
The average discharge of the Amazon is over 200,000 cubic meters per second or over 7 million cubic feet per second.
***Hodegskiss, Malcolm S. W, Peter W. Crockford, Yongbo Peng, Boswell A. Wing, and Tristan J. Horner. A productivity collapse to end Earth’s Great Oxidation. PNAS August 27, 2019. vol. 116 no. 35 17207-17212. DOI:
https://doi.org/10.1073/pnas.1900325116
**** https://obamamessiah.blogspot.com/2008/06/this-was-moment-when-rise-of-oceans.html
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