How the Mediterranean was Formed

Yerushalmi Shekalim 17a (Daf | Text):

כתיב (יחזקאל מז) ויאמר אלי המים האלה יוצאים אל הגלילה הקדמונה זה ים של סמכו <סיבוכא> וירדו אל הערבה זה ים של טבריא ובאו הימה זה ים המלח אל הימה המוצאים זה הים הגדול ולמה נקרא שמו מוצאים כנגד שני פעמים שיצא אחד בדור אנוש וא' בדור הפלגה רבי לעזר בשם רבי חנינה בראשונה יצא עד קלבריאה ובשנייה יצא עד כיפי ברבריאה רבי אחא בשם ר' חנינה בראשונה יצא עד כיפי ברבריאה ובשנייה יצא עד עכו ועד יפו (איוב לח) עד פה תבא ולא תוסיף עד עכו תבא ולא תוסיף ופה ישית בגאון גליך עד יפו אשית גאון גליך

My translation:

... Why is [the Mediterranean] called "Motze'im" [those who bring out]?  It corresponds to the 2 times that [the water] went out [from its original place]: once during the generation of Enosh and once during the generation of the dispersion.  Ribbi Elazar in the name of Ribbi Hanina says: At first, it went out until the Calabria and in the second, it went out until the Barbary Coast.  Ribbi Aha in the name of Ribbi Hanina says: At first, it went out until the Barbary Coast and in the second, it went out until Acco and until Yaffo...

A similar חז"ל exists in Bereishit Rabba at the end of Parasha 23.

So, according to Ribbi Aha, during the generation of Enosh, the Mediterranean basin, which was completely dry, opened up at the Strait of Gibraltar and the Atlantic waters flooded the basin until the Barbary Coast (this possibly means until Libya) and during the time of the Dor Hapelaga, the waters went eastward until the Land of Israel's cities of Acco and Yaffo.

This somewhat corroborates the science community's theory on this:

The flood affected only the Western Mediterranean at first, because the Sicily Sill (located at the present Straits of Sicily) formed a barrier separating its basin from the Eastern Mediterranean basin;^[27] in addition a sill may have existed in the eastern Alboran Sea at this time.^[28] While it was at first assumed that the filling of the eastern Mediterranean would have taken thousands of years, later estimates of the size of the Strait of Gibraltar channel implied that it would have taken much less, potentially less than a year until reconnection.^[29] A 2018 study suggested that the Mediterranean reversed water losses in around two years.^[30]

Even though scientists believe that the Mediterranean was first full of water, then dried up, and then refilled, it is interesting that they consider this a 2-step process.

Ribbi Elazar's opinion is somewhat different.  See how the Maharz"o on Bereishit Rabba explains it - that in the width of the Mediterranean, it first was a thin flood that reached until Eretz Yisrael, but its width was small and only reached until Calabria (the heal of the boot of Italy).  Later, the width of the sea widened until its width reached North Africa.

Rav Betzalel Stern ZT"L in his Betzeil HaHochma 2:12:6 gives a novel approach that there actually was a sea next to Eretz Yisrael originally and when the Strait of Gibraltar opened and flooded the Mediterranean basin, it connected the Atlantic waters to the sea that was next to Eretz Yisrael.  He brings a proof to this from another gemara.

Note that the Rada"l interprets כיפי ברבריאה as the land next to the Strait of Gibraltar.  This is difficult to explain, and the Betzeil HaHochma in 2:17 questions this too (although the Sefer Yuchsin seems to agree with the Rada"l).

Another monkey wrench in this is the Sefer Yuchsin's quote from Yosifon (this version of Yosifon doesn't say it quite the same way) that Alexander the Great came to islands near India and found the grave of Keinan (the son of Enosh) with writing that says that there were 2 floods - one in the days of Enosh and one in the days of Keinan.  The Sefer Yuchsin wants to say that the Midrash refers to these 2 floods.

In a way, this would make more sense since both are before the Mabul.  (However, it's not what the Midrash actually says.)  However, according to the Midrash and Yerushalmi - that the 2 floods occurred during the generation of Enosh and Dor Hapelaga, it comes out that the Mabul flooded the entire world in between these 2 floods.  I suppose that the Eastern Mediterranean could have dried up after the Mabul, but it's odd that no one mentions this.

Finally, I would like to point out that the verse that talks about Peleg being named Peleg since his father Ever knew that the world would be split up at the end of his life (see Seder Olam) states:

כִּי בְיָמָיו נִפְלְגָה הָאָרֶץ

for in his days was the earth divided

This makes perfect sense according to the Yerushalmi and Midrash.  This is because Europe was totally divided from Africa at that time.  It answers why he didn't name him נפץ as the Torah states what occurred - that people were scattered throughout the earth.  This is also true, but a huge thing that occurred at that time was that the continents divided.