Four Cities Forecast: California Update February 23, 2011

john's picture


The magnitude 6.3 Canterbury, NZ earthquake that occurred on 22 February, severely damaging much of Christchurch, serves to remind all of us that major earthquakes can occur at any time, potentially affecting many major cities around the globe.  Since July 2010, we have been periodically updating the time dependent probability of major earthquakes in California near four of its principal cities, using an experimental new methodology.

The four cities forecast for California is the probability of experiencing a major earthquake having magnitude > 7 during the 12 months from now within 150 miles of the four cities shown.  The charts below are an update of the four cities forecast for California.  Previous updates to this forecast can be found in postings on July 8, 2010 and afterward.  Detailed explanations and details of how to read these charts can be found there.

It can be seen that the chances of a major earthquake within 150 miles of these four cities have continued to increase, especially near San Diego, since the last posting on September 15, 2010.  This is because the numbers of small earthquakes, which are used as markers for stress increase since the last earthquake, have continued to accumulate. 

The plot shown below shows the chance of an M7 earthquake as a function of time for the four California cities, calculated using the experimental methodology.


Below we show in tabular form the chances of an M7 earthquake and how these have changed with time.


DavidAlexander's picture

Earthquakes are happened suddenly and people should alert to leave the place immediately. According to the research paper services, the goverment should announce the details about earthquake and vacate the people from the place. These 4 cities are damaged a lot by earthquake.

jenniferbrownz's picture

In the image below, we show the location of the event together with the forecast contours. The earthquake occurred on top of the only prominent hotspot in South Africa. read Kissmanga chapters for free

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