5,300 Global Earthquakes, 1973 to 2011, Graphed by Quantity per Day.

November 13, 2011 – 5,300 Global Earthquakes by Quantity per Day: I downloaded 5,300 global earthquakes: from January 1, 1973 to November 12, 2011; greater than or equal (>=) to a magnitude of 6.0. I summarized the number of earthquakes per day. The graph above reflects that summarization. In other words, the first bar (labeled 1x) summarizes the days when only one earthquake occurred. The next bar (labeled 2x) indicates that 715 times, two earthquakes occurred on the same day that were >= to 6.0M. The last bar (Labeled 12x) shows that one day saw an incredible 12 earthquakes. Not shown on this graph is March 11, 2011; the day of the mega-quake of the East Coast of Honshu, Japan. On that day a remarkable 42 earthquakes occurred.
If you take the numbers for each bar on the chart, they add up to 5,299. I did not plot the 42 earthquake day, as the chart would be distorted.
I was surprised on how many days had multiple earthquakes. For example, their were 41 occurrences of four earthquake the same day (4x bar). Further, if you look at these earthquakes by location; the first earthquake may not be the biggest one. In other words, the aftershocks occurring after a quake, may be bigger than the first tremor. This reflects the sudden and unexpected nature of earthquakes.
Let us hope that we never have an instance of a “12x” day along the West Coast of the United States. The Juan de Fuca fault zone; bordering Oregon, Washington State and Vancouver, British Columbia in Canada; has not had a major earthquake in some time. The Juan de Fuca fault zone marks the west central area of the “Ring of Fire” that surrounds the Pacific Ocean, and is home to over 80% of the world’s major quakes. The worst case scenario would be a release of the San Andreas Fault line from the Salton Sea, continuing up California just east of Los Angeles, directly through San Francisco and just of the coast of Oregon, Washington State and Vancouver. A mega event, such as this, on a “12x Day” would be a catastrophe of unimaginable proportions.
The Master of Disaster