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Earthquake Predictions
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San Francisco Panorama,© 2007 Can Balcioglu, iStock Photos Inc.
(1) COAST & OFF THE COAST,
NORTHERN CALIFORNIA & OREGON
BORDER REGIONS
Newly defined - August 2011
The region now includes earthquake events within a radius of
400 km from a center at Lat 41.29° and Lon -125.95°, 160 km west of Orick, CA. This includes all the activity of the Mendocino Triple Junction nearest to the coast and at the southern end of the Cascadia Subduction Zone, and extends NW to include the eastern half of the
so-called Blanco Fracture Zone. The region has been newly defined to achieve more homogeneity in the data sets because of interaction between earthquakes.
This region has experienced 15 strong earthquakes (M6.0-M6.8) and 5 major earthquakes (M7.0-M7.2) since the beginning of 1975.
(USGS/NEIC source).
(2)"NORTHERN & CENTRAL CALIFORNIA"
including Western Nevada
Newly defined - August 2011
This region now includes earthquake events within a 450 km radius
of Redwood Valley, CA, at Lat 39.265° Lon -123,204°. The northern arc passes through southernmost Oregon, while the southern arc crosses just below Fresno, CA. This region has been extended because of important interactions between earthquakes. The region now includes events off the coast near Eureka, CA, in the so-called Mendocino Triple Junction Region.
This region has experienced 18 strong earthquakes of magnitudes 6.0-6.9, and 5 major earthquakes, M7.0-M7.2, since the beginning of 1975. (USGS/NEIC source)
All earthquake predictions for the above regions are for the largest earthquake in a nominated period, plus an error margin of about one day, but no attempt is made to make forecasts for all periods because of the constraints of private research. Each table, with its original earthquake prediction, will remain subject to revisions or updates for 10 days.
Why updates may be necessary... because earthquakes interact in a very dynamic system. Just as in reporting the weather, the latest information must be taken into account to improve forecasting.
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SCROLL DOWN FOR TABLES
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STATISTICS FOR EARTHQUAKE PREDICTION For period 13 August 2007 - 12 July 2008 (256 predictions)
SUCCESS RATES*
Mag Observed Events Predicted Events
(How many predicted?) (How many observed?)
Pred. Obs. %Correct Obs. Pred. %Correct
<M4 60 67 = 90% 58 66 = 88%
M4.0-4.9 76 85 = 89% 57 60 = 95%
M5.0-5.9 73 77 = 95% 90 96 = 94%
M6.0+ 25 27 = 93% 29 34 = 85%
___________________________________________ *These statistics are updated periodically and refer to tabled predictions only, as no attempt
is made to predict all large earthquakes worldwide. Note that currently successful predictions are those which are ≈80% accurate on magnitude, and within a 10-day time window (plus an error margin of about one day), reflecting the fact that earthquake prediction is still an imprecise science. However, research here is aimed at improving this margin and currently 75% of all magnitude predictions have an error margin of only 15%. Any apparent numerical discrepancies between the two halves of the above table are due to the error margins: for example, an M6 category predicted quake might have come in at M5.8
OVERALL success rate from 256 predictions worldwide-
Observed events that were predicted (234/256) = 91.4%
Predicted events that were observed (234/256) = 91.4%
SCIENTIFIC: Correlation of Predicted & Observed Magnitudes
There is a highly significant correlation (r=0.90, P< .0001) between the full set of observed and predicted magnitudes, including 'false alarms' (Worldwide N=256 as of 12 July 2008).
EARTHQUAKE PREDICTION TABLES
M= Earthquake magnitude. See HOME page for further explanation of table entries.
Earthquake Location Maps - see the USGS web site for maps of earthquakes in these tables.
New 3-layer Table Format & Prediction Rules (25 Nov 07)
Please read following points to fully explain tables below:
1. The Original Earthquake Prediction, and details relating to it, are given in the top light blue layer of each table.
The 'expected date' (or dates) given here provide the best current estimate of when the largest earthquake event is most likely within the nominated 10-day window (date prediction made +10, or possibly ≈11 days). Please note that the time window now includes an error margin of ≈1 day which may extend it to include some closely predicted events, reflecting the fact that earthquake prediction is an imprecise science. The above estimates and other details may be updated, if necessary, in the next section of the table.
The Expected Range in Magnitude is given as the predicted magnitude +/-1 magnitude, or less (as shown). Analyses show that 85% of predictions can be expected to fall within +/-1M of the predicted values, regardless of the region of the world involved. Any predictions which fall outside these limits by as little as 0.1M will be regarded as unsuccessful.
2. Revisions, if required, are given in the mid blue layer of each table, and these revisions are used in the final assessments of the results. Please see the statement above explaining why updates are desirable, and note that revisions are limited to a 10-day window. Revisions usually relate to
earthquake magnitude and expected timing, but may also include location.
3. The Observed Earthquake and details (for the event we were attempting to predict) are given in the bottom dark blue layer of each table. The event recorded here is the largest earthquake for the nominated 10-11 day period. 'PENDING...' simply means that the anticipated event has not yet happened, or that we are waiting for the event to be posted on the web site.
NORTHERN CALIFORNIA,
& OFF THE COAST OF NTH CA - OREGON
Two tables may be running concurrently so please scroll down.
See also Long-term Forecasts
These Long-term Forecasts now give the approximate timing of the largest regional earthquakes for the lunar period ahead.
The Short-term tables below will be used to make revisable and, generally, more precise earthquake predictions for some of the important events that are indicated as being imminent in the Long-term Forecasts.
No. 46 Oregon-California Region
PREDICTED M3.2 Expected Date/Location Original prediction 2nd August 2-6 August (UTC) 2009 Predicted at 0012 hrs UTC Probability of event >85% within 400 km of Crescent City
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OBSERVED M2.8 Observed Date/Location Magnitude accuracy 87.5% 5th August at Lat 40.474 Lon -125.627 |
No. 45 Northern California
PREDICTED M3.5 Expected Date/Location Original prediction 14th April 14-24 April (UTC) 2009 Predicted at 2242 hrs UTC (time window open to 24th April +1 day margin) Probability of event >90% within 250 km of San Jose City Hall
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OBSERVED M3.7 Observed Date/Location predicted 3 days ahead here. 42 km North of Santa Rosa, CA |
No. 44 Northern California
PREDICTED M3.1 Expected Date/Location Original prediction 27 Jan 27-31January (UTC) 2009 Predicted at 0858 hrs UTC (time window open to 5th February) Probability of event >85% within 250 km of San Jose City Hall
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| OBSERVED M3.7 Observed Date/Location Magnitude accuracy 83.8% 00:20:29 hours, 6th February (accepted) Predicted 9 days ahead Lat 36.69 Lon -121.32 88 km SE of San Jose City Hall Central California |
No. 43 Coast & Off Coast Northern CA & Oregon
PREDICTED M3.6 Expected Date/Location Original prediction 31 Jan 4th February +/-3 days (UTC) 2009 Predicted at 0110 hrs UTC (time window open to 9th February) Probability of event >85% within 480 km of Lat 42.3 Lon -127.0
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| OBSERVED M2.9 Observed Date/Location Magnitude accuracy 80.5% 5th February at Lat 40.40 Lon -126.58 Predicted 5 days ahead 210 km WSW of Eureka, CA Off Coast of Northern CA |
No. 42 Northern California
PREDICTED M3.5 Expected Date/Location Original prediction 11 January 17 January +/-3 days (UTC) 2009 Predicted at 0427 hrs UTC (time window open to 21 January) Probability of event >85% within 250 km of San Jose City Hall
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REVISION nil |
| OBSERVED M3.8 Observed Date/Location Magnitude accuracy 92.1% 20 January at Lat 36.695 Lon -121.33 Predicted 9 days ahead 88 km SE of San Jose City Hall (USGS) Central California |
No. 41 Coast & Off Coast Northern CA & Oregon
PREDICTED M3.6 Expected Date/Location Original prediction 11 January 15 January +/-3 days (UTC) 2009 Predicted at 0436 hrs UTC (time window open to 21 January) Probability of event >85% within 350 km of Lat 42.3, Lon -127.0
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REVISION nil |
| OBSERVED M3.0 Observed Date/Location Magnitude accuracy 83.3% 11th January at Lat 41.83 Lon -123.85 Predicted same day 30 km ENE of Crescent City (USGS source) Northern California |
Previous tables have been deleted to save space