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If you have ever holidayed in Rome, probably you took a side trip to the Alban Hills, 15 miles south of the City.  The Alban Volcano Complex has been a get away spot for Romans for 1000s of years. Emperor Caligula took his mammoth ‘pleasure ship’ out for summer night spins around Nemi Lake in one of the Alban craters.  To escape city heat, Popes have retreated to their summer home at Castel Gandolfo above Albano Lake since 1700.

Given the recent interest in major earthquakes in the Pacific Northwest, it is interesting to re-examine the earthquake potential of the San Francisco Bay region.  In particular, we examine the probability of earthquakes having magnitude M>6 and M>7 in the most populated region around San Francisco.  The map below shows San Francisco bay, the latest WGCEP/UCERF2 earthquake fault map, and a rectangular selection region.  The figure was produced using the polygon selection with the Hazard Viewer.

The earthquake was near the Haida Gwai area, that has been the site of several large earthquakes recently.  A map of the region with the earthquake and a selection circle is below:

A strong earthquake occurred near Papua New Guinea a few hours ago on Saturday Apr 19 2014 at 06:27:59 GMT-0700 (PDT).  From the Hazard Viewer we can do a simple but rapid analysis.  The forecast from the Hazard Viewer was computed last night at midnight, a few hours prior to the earthquake.  The earthquake locations are shown below, with the bright red event being the M7.5 mainshock:

One February several years ago I was invited to give a presentation at the “Spring Meeting” of a Geological Club in Saint John’s Newfoundland. I arrived to face freezing rain and three inches of ice coating every possible exterior surface. I learn later that the “Spring Meeting” handle was an example of Newfoundland humor. I guess that same humor explains why Newfoundland Standard Time is GMT less  three  --- AND ONE HALF --- hours.

Some computations from the hazard viewer.  This event is much closer to Iquique than the mainshock, probably more damage.

(Update  21:29 PDT: Magnitude now downgraded to 7.6)

Events and forecast map, together with selection circle.