Carl Drews and Weiqing Han of the Department of Atmospheric and Oceanic Sciences, University of Colorado at Boulder, conducted 19 computer simulation tests of wind setdown at three suggested locations for the sea crossing described in Exodus 14 (2010). Wind setdown is the drop in water level caused by wind stress acting on the surface of a body of water for an extended period of time. The three test locations for the sea crossing were the north end of the Gulf of Suez, the mouth of a coastal lagoon in the eastern Nile delta at Tell Kedua and the north end of Ballah Lakes in the Isthmus of Suez at Tell Abu Sefeh.
Gulf of Suez (Tests R1–R5)
It has been proposed that a high velocity wind could expose an underwater reef at the north end of the Gulf of Suez, thus providing a land bridge for crossing. A crossing in this area, however, does not fit recent data which would place the sea crossing at the north end of the Ballah Lakes (Byers 2006; Hoffmeier 2008: 54–57). Assuming that the north end of the Gulf of Suez is a feasible location, the test results do not indicate that the reef could be exposed by natural causes. To begin with, it would be necessary to assume the wind came from the northwest, in order to align with the axis of the Gulf of Suez. This is contrary to an east wind as recorded in Exodus 14:21. With a wind speed of 75 miles per hour (a Category 1 hurricane!), there would still be a low spot on the reef over a half mile long with minimum water depth of 20 inches flowing at a velocity of 3 feet per second. Moreover, this model does not produce a wall of water on either side of the crossing place as required by the biblical description (Ex 14:22), but rather a reef protruding from the water in some places and under water in other places.
Strait of Kedua (Tests T1–T5 and T8–T14)
In this case, the postulated crossing point is a 3 mile-wide east-west strait in the eastern delta between a small lagoon on the south and a large lake, which the investigators call the Lake of Tanis, a name given in Herodotus (fifth century BC historian), on the north. The strait is approximately 10 miles northeast of the more likely crossing location at the north end of the Ballah Lakes. Whether a large lake existed here at the time of the Exodus is highly questionable as geological investigations indicate that the area to the north of the small lagoon was open sea at that time (Hoffmeier 2005: 41–43). The investigators theorize that a narrow sandbar separated the Lake of Tanis from the Mediterranean Sea. With this model, a 62 miles per hour wind blowing from the east for 12 hours would produce a traversable dry gap in the strait for a period of about 4 hours (test T1). An east-west stream of water about 8 inches deep would form some 3 miles to the north of the crossing place and the lagoon to the south would be completely dry. This hardly constitutes “a wall of water on their right and on their left” (Ex 14:22). In test T9 it was assumed that the wind was from the southeast and in this case no dry passage formed. Several other tests were run with different variables, with no appreciable difference from the test T1 results (tests T2–T5, T8, T10, T11, T14).
In tests T12 and T13 it was assumed that the area north of the strait was open sea, which, based on the geological evidence, seems to be a more realistic reconstruction. With an east wind of 62 miles per hour blowing for 12 hours, no dry crossing formed. For a wind speed of 75 miles per hour, a passage would open for 4.6 hours. In this case there would be shallow water on the north of the passage and the lagoon to the south would be completely dry.
North end of Ballah Lakes (Test T6 and T7)
Based on currently available data, the north end of the Ballah Lakes appears to be the most likely location for the sea crossing. In this model an east wind did not produce a land bridge since the orientation of the Ballah Lakes is northeast-southwest. With a northeast wind of 62 miles per hour a dry crossing place appears for 2.8 hours. If the wind speed is increased to 75 miles per hour, the crossing time is increased to 8.4 hours. In both cases there would be no water on the north side of the crossing place and only shallow water on the south side.
While these computer simulations are interesting, none of them produce a result consistent with the biblical description of “a wall of water on their right and on their left.” In the end we must conclude that what took place when the Israelites left Egypt was a miraculous act of God which cannot be duplicated by a natural phenomenon.
Bibliography
Byers, Gary A.
2006 New Evidence from Egypt on the Location of the Exodus Sea Crossing. Bible and Spade 19: 14–22.
Drews, Carl, and Han, Weiqing
2010 Dynamics of Wind Setdown at Suez and the Eastern Nile Delta. PloS ONE 5(8), http://www.plosone.org/article/info:doi/10.1371/journal.pone.0012481 (accessed September 21).
Hoffmeier, James K.
2008 The Archaeology of the Bible. Oxford, England: Lion.