The last NERVS update may have been validated by a 4.9 Gulf of California quake quake within the vector magnitude and time window, though there seems to be some discrepancy from the USGS about its authenticity. A confirmed California quake occurred six days later (on 9/16), within the magnitude range but outside the time window. Quakes also occurred in the secondary and tertiary vectors, though several were just beyond the 10-day time window.
Likewise, you may recall this statement in the last NERVS update: "Longtime readers know that any Sunda Strait quake causes me some concern, since a 7.0 or greater quake usually follows within a short period of time somewhere else." While three weeks is not exactly a "short period of time", yesterday's 8.0 in American Samoa does seem to lend some credence to that observation. Similarly, a 6.2 quake in the country of Georgia on September 7 is noteworthy, since that area had been quiet for some time prior to the Sunda Strait quake, only to awaken with an event of significant magnitude four days after Sunda Strait.
As an ongoing hypothesis, a 7.0 or greater quake yields a NERVS update, since possible underlying conditions are powerful enough to produce another significant quake anywhere worldwide. The 8.0 American Samoa quake, plus quakes in Tonga, Japan, Myanmar, Crete, Italy and Eastern PNG yield the following NERVS update:
4.5 or greater magnitude quake in next 10 days:
- Primary vector: Southern California, Northern California, Central California, Oregon, Washington, Central Alaska
- Secondary vector: Utah, Nevada, Vancouver Island, Taiwan, Iran, Turkey, Italy, Canada
- Also possible: China, India, Western Brazil
NERVS Accuracy Check
Region: GULF OF CALIFORNIA
Geographic coordinates: 30.155N, 113.242W
Magnitude: 4.9 Mb
Depth: 10 km
Universal Time (UTC): 13 Sep 2009 07:06:31
Time near the Epicenter: 13 Sep 2009 00:06:31
Local standard time in your area: 12 Sep 2009 23:06:31
Geographic coordinates: 30.155N, 113.242W
Magnitude: 4.9 Mb
Depth: 10 km
Universal Time (UTC): 13 Sep 2009 07:06:31
Time near the Epicenter: 13 Sep 2009 00:06:31
Local standard time in your area: 12 Sep 2009 23:06:31
(though there seems to be some discrepancy from the USGS about this event's accuracy)
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For those new to the list, NERVS stands for:
Numerical (or "non-scientific")
Earthquake
Risk
Vector
System
...and is based on prior California quakes being preceded by similar patterns of quakes in other areas.
***NEW***
Water, water everywhere and not a drop to drink?
Damaged or broken supply pipes, compromised treatment facilities or loss of pressure could make obtaining clean water a top priority after a major quake. Don't forget about your water heater—it's a great resource for gallons of usable water. Keeping the water inside is one reason to brace it.
A spigot or other outflow device should be present on the bottom of your gas or electric water heater. Examine the top as well—you may have faucet handles or other shut-off valves to limit inflow of contaminated water. Remember that multiple strong aftershocks can continue after the initial quake, so make sure the gas is off before spending much time in front of your water heater, and avoid any ignition source until you're sure residual gas has had time to clear. More: http://www.earthquakecountry.info/daretoprepare/stuff/waterheater.html
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Your fault? If buying a home in the Bay Area, you may also be buying increased risk. Your disclosure packet should contain an assessment of earthquake risk based on your home's proximity to known faults. The Association of Bay Area Governments (ABAG) uses the Modified Mercalli Intensity scale to rate estimated quake damage. See a description here: http://www.abag.ca.gov/bayarea/eqmaps/doc/mmi.html
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What California emergency services are available before and after a large event? See the California Emergency Management Agency's plan. http://www.oes.ca.gov/WebPage/oeswebsite.nsf/Content/A1F2F25F0947AF848825741F006015EF?OpenDocument
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An SF earthquakes service is available on Twitter. Thanks to NERVS member Dan for the resource. http://twitter.com/sfearthquakes
And if Google is more your style, here's a new way to search for quakes. Thanks to NERVS member Mark for the resource. http://googleblog.blogspot.com/2009/03/shaking-up-earthquake-searches.html
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If you live in the Bay Area, don't miss the USGS simulation of a 6.8, 7.0 or 7.2 quake on the Hayward and Rodgers Creek faults.
When you get to the page, click on the images to yield the animated versions. Also available in HD.
Get an earthquake education from UC Berkeley for free! Available from iTunes U, "Earthquakes In Your Backyard" covers many interesting physical and social aspects of geologic science. Check out iTunes for more:
For preparedness and response information, see:
Earthquakes in the Bay Area may cause dam or soil failure. Are you at risk in a flood or liquefaction zone? Check and see:
Note: When you see the map, choose the Zoom In tool. Then just click and drag to magnify your area of interest.
What could happen in a typical office during a quake? See the simulation:
What would happen to homes if a 6.7 temblor occurred in the Bay Area? The Structural Engineering and Earthquake Simulation Laboratory (SEESL) provides these room-by-room videos of a 6.7 simulation:
Archived Test Videos
When is an uplifting experience a bad thing? When it's caused by bulging magma in the United States' largest volcano. If your travel plans are taking you to Yellowstone in the near future, first check the Yellowstone Volcano Observatory alerts and updates:
Just how large is the Yellowstone caldera? View the Google map provided by NERVS list member Caleb Tonn:
Thank you for participating in this experiment. Please reply by email to let me know if you'd like to add persons or be removed from this list.
Nate
