Two west coast quakes, one in Oregon and one in the Gulf of California, occurred since the last NERVS update. A full schedule prevented me from sending out updates prior to their occurrence, but the overall pattern preceding these quakes is consistent with the NERVS hypothesis.
The latest general quake activity is similar to what's been happening through most of 2009--a high frequency of relatively low magnitude quakes. However, a 5.7 quake occurred to the west of Gibraltar Tuesday evening. I've been keeping my eye on this region for two main reasons: it is among recent California quake predecessors, and it may be linked to another region (Central U.S.) that operates in a vector manner similar to the West Coast. Additionally, the previous quake near Gibraltar preceded a series of powerful quakes in Indonesia in 2007.
The Gibraltar quake, along with an incomplete but recognizable vector pattern, yields the following NERVS update:
4.5 or greater magnitude quake in next 10 days:
- Primary vector: Missouri, Mississippi, Arkansas, Kentucky, Illinois, Indiana, Tennessee, Iowa, Ohio, Dominican Republic, Virgin Islands, Martinique, Utah
- Secondary vector: California, Nevada, Oregon, Washington, Alaska
- Also possible: Japan (large), Indonesia (large), large eruption of Mayon volcano in Philippines
***SPECIAL SECTION***
Past NERVS updates included the observation that quake frequency has risen noticeably in the last few years compared to the early 2000s. At the same time, overall magnitudes seem to have dropped. However, 2009 has seen two changes: greater frequency of quakes AND a larger number of high magnitude (7.0 or greater) quakes.
In 2004, an increase in frequency of high magnitude quakes ultimately led to the 9.2 Indian Ocean quake and subsequent tsunami (originally registered as 8.5 by the USGS as indicated below). It is possible that an increase of high magnitude quakes will generally precede a 9.x quake.
Based on a comparison of 7.0 or greater quakes that occurred in 2004 and 2009, and taking into account the hypothesis stated above, it seems possible that another 9.0 or greater quake may occur sometime in 2009 or early 2010. This would be significant:
"Since 1900 the only earthquakes recorded with a greater magnitude [than the 2004 Indian Ocean quake] were the 1960 Great Chilean Earthquake (magnitude 9.5) and the 1964 Good Friday Earthquake in Prince William Sound (9.2). The only other recorded earthquake of magnitude 9.0 or greater was off Kamchatka, Russia, on November 4, 1952 (magnitude 9.0)." - Wikipedia
Quakes with magnitude 7.0 or greater: January - December, 2004
2004/07/15 04:27 M 7.1 FIJI REGION Z=560km 17.48S 179.01W
2004/09/05 10:07 M 7.0 S. COAST OF WESTERN HONSHU Z= 20km 33.09N 136.63E
2004/09/05 14:57 M 7.1 S. COAST OF HONSHU, JAPAN Z= 10km 33.15N 137.04E
2004/10/09 21:26 M 7.1 COAST OF NICARAGUA Z= 61km 11.41N 86.55W
2004/11/15 09:06 M 7.0 WEST COAST OF COLOMBIA Z= 10km 4.61N 77.54W
2004/11/22 20:26 M 7.3 OFF W. COAST OF S. ISLAND, N.Z. Z= 10km 46.57S 164.83E
2004/11/26 02:25 M 7.2 PAPUA, INDONESIA Z= 35km 3.63S 135.48E
2004/11/28 18:32 M 7.0 HOKKAIDO, JAPAN REGION Z= 44km 43.00N 145.09E
2004/12/23 14:59 M 8.1 MACQUARIE ISLAND Z= 10km 50.24S 160.13E
2004/12/26 00:58 M 8.5 OFF W COAST OF NORTHERN SUMATRA Z= 10km 3.30N 95.78E
Quakes with magnitude 7.0 or greater: January - October to date (10/24/2009)
2009-01-03 19:43:54 (Mw 7.6) NEAR N COAST OF PAPUA, INDONESIA -0.5 132.8
2009-01-03 22:33:42 (Mw 7.5) NEAR N COAST OF PAPUA, INDONESIA -0.7 133.2
2009-01-15 17:49:39 (Mw 7.3) EAST OF KURIL ISLANDS 46.9 155.2
2009-02-11 17:34:52 (Mw 7.0) KEPULAUAN TALAUD, INDONESIA 3.9 126.4
2009-02-18 21:53:49 (Mw 7.0) KERMADEC ISLANDS REGION -27.4 -176.4
2009-03-19 18:17:37 (Mw 7.9) TONGA REGION -23.0 -174.8
2009-04-07 04:23:34 (Mw 7.0) KURIL ISLANDS 46.1 151.4
2009-05-28 08:24:45 (M 7.1) NORTH OF HONDURAS 16.8 -86.2
2009-07-15 09:22:32 (Mw 7.8) OFF W. COAST OF S. ISLAND, N.Z. -45.7 166.6
2009-08-09 10:55:56 (Mw 7.1) IZU ISLANDS, JAPAN REGION 33.1 138.0
2009-08-10 19:55:39 (M 7.6) ANDAMAN ISLANDS, INDIA REGION 14.0 92.9
2009-08-16 07:38:26 (Mw 7.0) KEP. MENTAWAI REGION, INDONESIA -1.4 99.5
2009-09-02 07:55:02 (Mw 7.4) JAVA, INDONESIA -7.8 107.3
2009-09-29 17:48:19 (Mw 7.9) SAMOA ISLANDS REGION -15.6 -172.3
2009-09-30 10:16:10 (Mw 7.9) SOUTHERN SUMATRA, INDONESIA -0.8 99.9
2009-10-07 22:03:15 (Mw 7.8) VANUATU -13.1 166.2
2009-10-07 23:13:49 (M 7.1) VANUATU -13.1 166.3
2009-10-07 22:18:26 (Mw 7.7) SANTA CRUZ ISLANDS -12.6 166.3
2009-10-08 08:28:47 (M 7.0) VANUATU -13.1 166.1
2009-10-24 14:40:44 (Mw 7.0) BANDA SEA -6.2 130.3
***End Special Section***
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NERVS Accuracy Check
...will be completed at a later time
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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.
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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:
http://maps.google.com/maps/ms?hl=en&gl=us&ptab=2&ie=UTF8&msa=0&msid=114896433391258936310.00043ec877e3a5d8328f8
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
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