Revelation 16:20: And every island fled away, and the mountains were not found.

The greatest earthquake of all time will occur during the seventh Vial Plague.¹ This unprecedented earthquake will cause every island² (continent)³ to reunite into a single landmass.⁴ The earth's continental geology will be restored to its original condition with one large landmass. This was the continental condition that existed at the time of the physical creation and before the flood in the days of Noah.⁵

Scientists generally agree that there was once a supercontinent⁶ called Pangea, which means all lands.⁷ They theorize that millions of years of continental drift⁸ divided Pangea through a geological mechanism called plate tectonics.⁹ However, the scriptures say this division took about 200 years¹⁰ from the time of the universal flood in the days of Noah¹¹ until the days of Peleg.¹² Genesis 10:25 describes the division of the earth in the days of Peleg as an actual separation of the eastern and western hemispheres,¹³ and not a political division of people as some scholars suggest.¹⁴

The great earthquake of the seventh Vial Plague will rejoin and effectively marry the two hemispheres as they existed before the flood.¹⁵ The marriage of the eastern and western hemispheres will occur rapidly¹⁶ as the Atlantic ocean is driven back into the north countries, and the islands shall become one land as stated in Doctrine and Covenants Section 133:23.¹⁷ This sudden and massive shift in the continents will cause the entire earth to reel to and fro as a drunken man.¹⁸ To observers on the shifting earth this will appear as though the stars are hurled from their place in heaven.¹⁹

When John envisioned this greatest earthquake in history during the Third Woe,²⁰ he said the mountains were not found.²¹ By way of comparison and contrast, there will be a much smaller earthquake or foreshock at the end of the sixth seal in Revelation 6:14, which still lies in the future. This smaller, but destructive, earthquake will only cause mountains to be moved out of their place.²² In addition, during the third and greatest earthquake, Christ's glorified presence²³ will melt mountains.²⁴ They will flow down like hot wax²⁵ into valleys that will then be exalted or raised up as they are filled in.²⁶ The very tall mountains that exist in the world today will not be found after the third earthquake because all rough places will be made smooth.²⁷

The earth's topographical changes will also be accompanied by the complete renewal of the earth²⁸ to the same paradisaical (terrestrial)²⁹ conditions that existed before the fall of Adam.³⁰ The Second Coming is the day of transfiguration,³¹ when the earth will be made smooth and enjoy temperate weather conditions continually.³² This is all part of the new heaven and new earth that will come to exist when Christ comes again.³³