California's Governor declared a state of emergency after Sunday's earthquake hit and was the strongest in the region in 25 years. Dozens of aftershocks followed the 6.0 magnitude earthquake.
In fact, they could continue for weeks and that has many people asking; Could this earthquake be a lead up to 'the big one?'
Experts are saying not necessarily.
One clue is what's happened in two days since the earth shook.
David Oppenheimer, a Seismologist for the United States Geological Surve
y says, “We know that when we study earthquakes that about 5 to 10% of all main shocks are preceded by foreshocks. So as time progresses, the likelihood goes down. Immediately after the earthquake, there was a 54% probability that this was a foreshock. I think the numbers will fall further because this is not a very robust aftershock.”
But, if it feels as if you've heard more about major earthquakes recently, it may be because there have been more.
Researchers say in the first 3 months of this year, the rate of earthquakes with a magnitude higher than 7.0 was more than double the average since 1979.