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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
This new region (added 11 April 2008) covers the very seismically active areas from Cape Mendocino in Northern California to about
600 km west of Portland, Oregon, on the western margin of the Juan
de Fuca Plate and at the south end of the Juan de Fuca Ridge.
The region includes only locations within a radius of 350 km
from its central coordinates, Lat 42.30° and Lon -127.00°, and includes all the activity around the Mendocino Triple Junction at the southern end of the Cascadia subduction zone.
(2)"NORTHERN CALIFORNIA REGION" is narrowly defined (02-02-08) for the purpose of earthquake prediction to include only locations within 250 km (155 miles) radius* from San Jose City Hall. The northern arc crosses the coast 26 km below Mendocino (197 km north from San Francisco) while the southern arc crosses between Morro Bay and San Luis Obispo. The region, centered on San Jose at Lat 37.3° and Lon -121.86°, includes San Francisco, Oakland, and Sacramento, and extends east to Lake Tahoe.
* As of 19th July 2008, predicted events for the 'Northern California Region' must fall within a radius of 250 km
of the San Jose coordinates as given above, otherwise they will not be considered successful even if the magnitudes are within the predicted range. Previously a 10% error margin was allowed, but studies are aimed at removing these error margins from all regional study areas over the coming months.
Earthquake predictions are being made more relevant to the largest cities by downsizing the regions under study, as research advances to make this focusing possible.
This is the third significant downsizing of the 'Northern California' region:
(1) Prior to 16 November 2007 predictions were accepted if they fell between about latitudes 36°in Central California and 44° off Oregon.
(2) Between 16 November 2007 to 2 February 2008, the region included only those locations that fell within a 400 km radius (250 miles) of Sacramento.
(3) This third restriction of the region to within a 250 km radius of San Jose represents a reduction of 60% of the previous area in point (2) above, which has been made possible by the author's latest research.
All earthquake predictions for the above regions are for the largest earthquake in a nominated 10-day 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 bi-monthly 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, for each event after 14th July 2008, is given as the predicted magnitude +/-1 magnitude (previously it was given as +/-0.5M). Statistical analyses of over 100 of the latest predictions show that 95% of them can be expected to fall within +/-1M of the predicted values, regardless of the region of the world involved. From 14th July 2008, any predictions which fall outside these limits by as little as 0.1M will be regardedas 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
No. 39 Northern California
PREDICTED M4.5 Expected Date/Location Original prediction 7 June 2008 7-17 June (UTC) 2008 Predicted at 0530 hrs UTC (time window open to 17 June, plus ≈1 day margin) Probability of event >90% within ≈250 km of San Jose City Hall
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REVISED to M4.0 Expected Date/Location Revised at 0212 hrs on 11 June 11-13 June, but window open as above |
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OBSERVED M3.1 Observed Date/Location at Lat 36.68°, Lon -121.31° , 90 km SE of San Jose City Hall.
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No. 38 Coast & off the Coast of Northern CA-Oregon
PREDICTED M4.0 Expected Date/Location Original prediction 7 June 2008 7-17 June (UTC) 2008 Predicted at 0510 hrs UTC (time window open to 17 June, plus ≈1 day margin) Probability of event >90% within ≈350 km of Lat 42.3° Lon -127.0°
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REVISION nil
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| OBSERVED M4.9 Observed Date/Location Magnitude accuracy 81.6% 14 June at Lat 44.23° Lon -129.18° Predicted 7 days ahead 396 km WNW of Bandon Off Coast of Oregon |
No. 37 Coast & off the Coast of Northern CA-Oregon
PREDICTED M6.3 Expected Date/Location Original prediction 25 May '08 25-30 May (UTC) '08 Predicted at 0335 hrs UTC (time window open to 4 June, plus ≈1 day margin) Probability of event >85% within ≈350 km of Lat 42.3° Lon -127.0°
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REVISION nil
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| OBSERVED M4.9 Observed Date/Location Magnitude accuracy 77.8% 2nd June, Lat 44.18° Lon -129 22° Predicted 8 days ahead 405 km WNW of Bandon OR The only quake >M4.0 in the period. Off the Coast of Oregon |
No. 36 Coast & off the Coast of Northern CA-Oregon
PREDICTED M3.5 Expected Date/Location Original prediction 24 Apr '08 24 Apr- 4 May (UTC) '08 Predicted at 0103 hrs UTC (time window open to 4 May, plus ≈1 day margin) Probability of event >85%
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NOTE: The author was absent during this period and unable to review the above prediction as events unfolded at the end of April. |
| OBSERVED 5.4 Observed Date/Location Magnitude accuracy 64.8% 30 April, Lat 40.837° Lon -123.499° Predicted 6 days ahead 55 E of Eureka, CA |
No. 35 Northern California
PREDICTED M3.6 Expected Date/Location Original prediction 20 Apr '08 20-30 Apr (UTC) '08 Predicted at 0027 hrs UTC (time window open to 30 April, plus ≈1 day margin) Probability of event >85%
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REVISION if needed is posted here
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| OBSERVED M3.6 Observed Date/Location Magnitude accuracy 100% 29 April, Lat 35.49° Lon -120.78° Predicted 9 days ahead 225 SSE of San Jose City Hall Northern California |
No. 34 Off the Coast Northern California - Oregon
PREDICTED M7.0 Expected Date/Location Original prediction 11 Apr '08 11-14 Apr (UTC) '08 Predicted at 2352 hrs UTC (time window open to 21 April, plus ≈1 day margin) Probability of event >65%
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REVISED to M5.1 Expected Dates Revised range M4.6-M5.6 Probability of event >90% |
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OBSERVED M4.1 Observed Date/Location
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No. 33 Northern California
PREDICTED M3.5 Expected Date/Location Original prediction 7 Apr '08 7-9 Apr (UTC) '08 Predicted at 0315 hrs UTC (time window open to 17 April, plus ≈1 day margin) Probability of event >90% within ≈250 km from San Jose
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REVISION nil
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OBSERVED M3.0 Observed Date/Location Predicted 8 days ahead 122 NNW from San Francisco, CA |
No. 32
PREDICTED M4.2 Expected Date/Location Original prediction 22 Mar '08 22-24 Mar (UTC) '08 Predicted at 0542 hrs UTC (time window open to 1Apr, plus ≈1 day margin) Probability of event >85% within ≈250 km from San Jose
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REVISED to M4.1 Expected Dates Revised at 0042 hrs on 27 March 27-28 Mar, but window open as above Updated range M3.5-M4.5 |
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OBSERVED M 3.2 Observed Date/Location
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No. 31
PREDICTED M4.9 Expected Date/Location Original prediction 9 Mar '08 9-12 Mar (UTC) '08 Predicted at 0653 hrs UTC (time window open 10 days to 19 Mar + 1 day margin) Probability of event >85% within 250 km from San Jose
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REVISED to M3.9 Expected Dates Revised at 0559 hrs on 9 March March 10-11 Updated range M3.4-M4.4 |
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OBSERVED M3.4 Observed Date/Location Magnitude accuracy 87.2% 10 March, Lat 39.355°, Lon -123.277° Predicted 1 day ahead 180 km WNW Sacramento 250 N of San Jose |
No. 30
PREDICTED M4.2 Expected Date/Location Original prediction 23 Feb '08 23-27 Feb (UTC) '08 Predicted at 0418 hrs UTC (time window open 10 days to 4 Mar) Probability of event >90% Within 250 km radius of San Jose City Hall
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REVISIONS nil
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OBSERVED M4.1 Observed Date/Location Magnitude accuracy 97.6% 24 February, Lat 38.818° Lon -122.809° Occurred 05:32:10 hrs Predicted 25 hours ahead 42 km NNW from Santa Rosa 120 km NNW of San Francisco |
No. 29
PREDICTED M4.3 Expected Date/Location Original prediction 3 Feb '08 3-5 February (UTC) '08 Predicted at 0739 hrs UTC (time window open 10 days to 13 Feb) Probability of event >90% within 250 km radius of San Jose City Hall |
REVISED to M3.3 Expected Date Revised at 0745 hrs on 10 Feb 10-13 February, UTC
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OBSERVED M2.2 Observed Date/Location Magnitude accuracy 66.7% 13 February, Lat 38.82 Lon 122.82 Predicted fall 3 days ahead Details subject to revision by seismologist 121 km WNW Sacramento |
No. 28
PREDICTED M3.5 Expected Date/Location Original prediction 24 Jan '08 24-29 January (UTC) '08 Predicted at 0603 hrs UTC (time window open 10 days to 2 Feb) Probability of event >95%
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REVIEWS nil
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OBSERVED M3.7 Observed Date/Location Magnitude accuracy 94.6% 28 January at Lat 39.31, Lon -119.96 Predicted 4 days ahead NNW from Sacamento
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No. 27
PREDICTED M3.9 Expected Date/Location Original prediction 10 Jan '08 10-12 January (UTC) '08 Predicted at 0203 hrs UTC (time window open 10 days to 20 Jan) Probability of event >95%
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REVIEWS nil
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OBSERVED M4.7 Observed Date/Location Magnitude accuracy 83.0% 19 January Lat 40.12, Lon -122.76 Predicted 9 days ahead 60 km SSW from Redding, Nth CA Northern California |
No. 26
PREDICTED M4.2 Expected Date/Location Original prediction 21 Dec '07 21-24 December (UTC) '07 Predicted at 0830 hrs UTC (time window open 10 days to 31 Dec) Probability of event >90%
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REVIEWS Nil
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OBSERVED M3.1 Observed Date/Location Magnitude accuracy 73.8% 28 December '07 M4.4 just outside zone 24 December '07 |
No. 25
PREDICTED M4.2 Expected Date/Location Original prediction 8 Dec '07 8-10 December (UTC) '07 Predicted at 2250 hrs UTC (time window open 10 days to 18 Dec) Probability of event >95% within a 400 km radius of Sacramento |
REVISION Expected date/Location 11-18 December (See time window above) |
| OBSERVED M3.5 Date/Location
Magnitude accuracy 83.3% 11 December '07 Predicted 1.4 days ahead Lat 36.55, Lon -121.12, 225 S of Sacramento CA _____________________________________
NOTE (11 Dec) - A 'near miss' as recorded below: M4.8 - 460 km WNW of Sacramento, CA (Magnitude 88% accurate), but this offshore event was outside prediction zone by only 60 km. |
No. 24
PREDICTED M4.9 Expected Date/Location Original prediction, 1 Dec '07 1-3 December (UTC) '07 Predicted at 0640 hrs UTC (time window open 10 days to 11 Dec) Probability of event >95% within a 400 km radius of Sacramento |
REVISED to M4.3 Expected Date Revised at 2035 hrs on 1 Dec 1-2 December UTC Updated range M4.2-M4.4 (time window remains open to 11 Dec)
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OBSERVED M4.0 Observed date/Location Magnitude accuracy 93.0% 1 December UTC at 20:50:12 hrs Original prediction made 14 hrs 10 min 118 km WNW Sacramento CA ahead; Magnitude adjusted 15 min ahead Lat 38.82, Lon -122.79 |
No. 23
PREDICTED M4.0 Expected Date/Location Original prediction, 16 Nov '07 16-17 November (UTC) '07 Predicted at 0755 hrs UTC &n |