Hi All,
Quakes in the South Sandwich Islands, Tonga, Central Mid-Atlantic Ridge, Balleny Islands, Komandorskiye Ostrova, Russia, Kermadec Islands, Solomon Islands, and New Britain Region, PNG yield the following NERVS update:
4.5 or greater magnitude in next 10 days:
- Primary vector: Oregon (including offshore), Northern California, Southern California (including Baja and offshore), Central California
- Secondary vector: Idaho, Washington, Utah, Nevada, Wyoming, Arizona, New Mexico, Oklahoma
- Also possible: Costa Rica, Myanmar, Sikkim (India), Pakistan, Taiwan, Mongolia, Colombia, Ecuador, Iran, Turkey, or a large quake near the Banda Sea
NERVSupdate Twitter feed accuracy report
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The NERVSupdate Twitter feed was added in 2011 to provide more rapid but less rigorous notification of possible NERVS pattern development. For those interested, the table below shows its accuracy. Date range is October 21, 2011 through July 4, 2014, with the most recent tweet sent on June 23, 2014.
Interpretation of Results
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As might be expected from a less-rigorous analysis prior to notification, the 94% Overall Exact or Close Date Accuracy appears to confirm the efficacy of NERVS pattern development from a time perspective (within 15 days), but less so for location plotting. In other words, general NERVS patterns tend to produce more easily observable and consistent time frames, but specific precursor events need further review to determine likely event locations.
Accuracy Assessment Details
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- The NERVS experiment protocol is, strictly, California quakes of 4.5 or greater magnitude within 10 days of a NERVS update. More loosely, it covers events within the same time period and magnitude range, but encompasses a larger geographic region: Haida Gwaii (Canada) to the North, Nayarit or Jalisco, Mexico to the South (this southern range is still being debated), and extending into the Western US states: OR, WA, ID, NV, UT, AZ, NM, CO, WY and MT. (Oklahoma is a region of interest, but is currently outside the expanded geographic range.) Tweets were tallied with the following considerations:
- "Resolved Tweets" means that after a tweet was made, a subsequent corresponding event occurred.
- "In-Protocol Resolved Tweets" means that the tweet was within the bounds of the NERVS experiment protocol. Occasionally, I use the Twitter feed to make additional observations of seismic events.
- "Date Accuracy: Yes" means that a qualifying event occurred within the 10-day time period.
- "Date Accuracy: Close" means that a qualifying event occurred between 10 and 15 days from the tweet.
- "Date Accuracy: No" means that a qualifying event occurred more than 15 days from the tweet. Average time for next event to occur: 19.5 days.
- "Date and California Accuracy: Yes" means that a qualifying event occurred within the 10-day time period in California.
- "Date Accuracy: Close & California Accuracy: Yes" means that a qualifying event occurred between 10 and 15 days in California from the tweet.
Follow-up
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I'm planning on occasionally providing updates to this Twitter accuracy report. If you're interested in reviewing the full report, please send me a message.
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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.
Twitter Feed: To subscribe, please follow NERVSupdate
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
