The San Francisco Bay area was rocked by a 4.5 magnitude earthquake at 10.33pm local time on Monday, October 14. Many felt shaking occur up to 40 miles away in San Jose, but the USGS has warned the worst may yet be to come. The earthquake monitoring service said there is a two percent chance there could be a follow up earthquake in the next week, which could be bigger than the 4.5 tremor.
This in turn could create a vicious cycle, where one earthquake causes another.
The USGS wrote on its website: “According to our forecast, over the next week there is a two percent chance of one or more aftershocks that are larger than magnitude 4.5.
“It is likely that there will be smaller earthquakes over the next week, with 0 to 4 magnitude 3 or higher aftershocks.
“Magnitude 3 and above are large enough to be felt near the epicentre.
“The number of aftershocks will drop off over time, but a large aftershock can increase the numbers again, temporarily.”
However, the USGS said that it is unable to predict accurately if and when an earthquake will occur.
The statement continued: “No one can predict the exact time or place of any earthquake, including aftershocks.
“What our earthquake forecasts do is give us an understanding of the chances having more earthquakes within a given time period.
Another reason why California is so earthquake-prone is that it sits upon the dreaded Pacifc Ring of Fire.
The Ring of Fire is the largest and most active fault line in the world, stretching from New Zealand, around the east coast of Asia, over to Canada and the USA and all the way down to the southern tip of South America and causes more than 90 percent of the world’s earthquakes.
The plates which make up the Ring of Fire are so huge even the slightest shift results in massive tremors, volcano activity and tsunamis.