Have you ever wondered what triggered the Genesis Flood? Genesis 7:11 tells us that a unique geologic event took place at the same moment as the Flood began: “In the six hundredth year of Noah’s life, in the second month, the seventeenth day of the month, on that day all the fountains of the great deep were broken up, and the windows of heaven were opened.”
Most creation geologists believe that the opening of “the fountains of the great deep” refers to the breakup of the earth’s crust into plates. The subsequent rapid, catastrophic movement of these plates would have released huge quantities of hot subterranean waters and molten rock into the ocean. As the hot water gushed through the fractured seafloor, the water flashed into superheated steam and shot high into the atmosphere as supersonic steam jets, carrying sea water that eventually fell as rain.
But what catastrophe might God have used to cause the earth’s crust—many miles thick—to crack? Some have suggested a meteorite or asteroid impact of unprecedented size and scope. Do we find any evidence? Geologists have discovered some gargantuous remnant craters and piles of debris, leftover from massive impacts that easily fit the bill.
A Smoking Gun in Australia?
One example of an impact powerful enough to trigger the Flood is the 56-milewide (90 km) Acraman impact crater in South Australia. It apparently resulted from a 2.5-mile-wide (4 km) asteroid that slammed into the Outback at almost 16 miles per second (26 km/s) (Figure 1). The explosion would have been equivalent to the detonation of 50,000–100,000 hydrogen bombs all at once! The impact blasted some of the pulverised pre-Flood crystalline basement rocks to sites 280 miles (450 km) away, and the debris accumulated in a layer 16 inches (40 cm) thick within some of the earliest Flood deposits.
An asteroid impact—or several simultaneous impacts—that triggered the Flood may also have been part of an ongoing, solar-system-wide catastrophe that lasted for months or years. If so, we would expect to find evidence of many other meteorites that subsequently hit the earth during God’s judgment on the planet. Two lines of evidence can be used to support this inference: (1) the rapid rate of past cratering during the Flood, and (2) the fields of meteorites left by this bombardment.