"In the six hundredth year of Noah's life, in the second month, the seventeenth day of the month, the same day were all the fountains of the great deep broken up, and the windows of heaven were opened" (Genesis 7:11).
Our text describes the primary physical causes for the Flood of Noah's day, as well as the primary sources for the vast waters which covered the earth. The first source is very interesting from a geological point of view, and to grasp some semblance of its meaning is necessary if we would understand the Flood.
As the "deep" in Scripture usually refers to the ocean (i.e., Genesis 1:2), so the "great deep" which was "broken up" evidently speaks of great subterranean reservoirs or chambers deep inside the earth, all of which spewed forth their contents at the same time. This breakup continued all over the earth for 150 days (see Genesis 7:11; 7:24; 8:2).
The reference to "broken up" merits attention, for it implies a wrenching of the earth's crust, a great tectonic event. The same word is used in Numbers 16:30-33 to describe the supernatural opening up of a great pit into which the rebellious Korah and his followers and their families fell, thereby squelching their mutiny against Moses's leadership.
Any such breaching of the earth's crust results in earthquakes and if occurring under water, results in devastating tsunamis (sometimes called tidal waves) traveling through the water at speeds approaching the speed of sound. Continued pulsation of these fountains all over the earth for 150 days would totally restructure the surface of the earth, demonstrating God's hatred for the sin of the antediluvian world. Coupled with the other factors involved in the Flood, it is no wonder that "the world that then was, being overflowed with water, perished" (II Peter 3:6). JDM