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Earthquake Predictions
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San Andreas Fault, Southern California
© 2007 William Royer, iStock photos Inc. All rights reserved.
SOUTHERN CALIFORNIA REGION is newly defined
(02-02-08) to include only locations within 250 km radius* (155 miles) from Los Angeles Civic Center. The northern arc crosses the coast
13 km below San Luis Obispo, north of Pt Arguello, while the southern
arc sweeps down around Ocotillo Wells and then Tijuana on the Mexican border before crossing the coast half-way between Tijuana and Ensenada in Baja CA, just 70 km south of San Diego.
* As of 19th July 2008, predicted events must fall within a radius of 250 km of Los Angeles, 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 'Southern California' region:
(1) Prior to 16 November 2007 the region was defined as lying between latitudes 24° in the Gulf of California to 36° in Central California.
(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 San Diego.
(3) This third restriction of the region to within a 250 km radius of Los Angeles represents a reduction of 60% of the previous area in point (2) above, and this has been made possible by the author's latest research.
All earthquake predictions for the Southern California Region
are for the largest earthquake in a nominated10-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 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.
SOUTHERN CALIFORNIA
See also Long-term Forecasts
No. 22
PREDICTED M4.0 Expected Date/Location Original prediction 26 Aug 27-28 August (UTC) 2008 Predicted at 2215 hrs UTC (time window open to 5 Sept) Probability of event >90% within 250 km of Los Angeles
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REVISION if needed is posted here |
| OBSERVED M3.3 Observed Date/Location Magnitude accuracy 82.5% 4th September Lat 34.00 Lon -117.12 Predicted 9 days ahead 104 km E of Los Angeles Civic Center Southern California |
No. 21
PREDICTED M4.8 Expected Date/Location Original prediction 19 July 19-22 July (UTC) 2008 Predicted at 2312 hrs UTC (time window open to 29 July) Probability of event >85% within 250 km of Los Angeles
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REVISED to M3.6 Expected Dates |
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OBSERVED M5.4 Observed Date/Location |
No. 20
PREDICTED M3.8 Expected Date/Location Original prediction 7 June 2008 7-17 June (UTC) 2008 Predicted at 0607 hrs UTC (time window open to 17 June, plus ≈1 day margin) Probability of event >90% within ≈250 km of Los Angeles Civic Center
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REVISED to M3.5 Expected Date/Location Revised at 0638 hrs on 9th June 9-17 June (UTC) Revised range M3.0-M4.0 Southern California |
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OBSERVED M3.0 Observed Date/Location |
No. 19
PREDICTED M4.2 Expected Date/Location Original prediction 21 May '08 21-24 May (UTC) '08 Predicted at 2306 hrs UTC (time window open to 1 June, plus ≈1 day margin) Probability of event >90% within ≈250 km of Los Angeles
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REVISED to M3.5 Expected Dates |
| OBSERVED M3.3 Observed Date/Location Magnitude accuracy 94.3% 25 May at Lat 32.475° Lon -117.872° Predicted 2 days ahead 76 km WSW of San Diego (USGS) 180 km S of Los Angeles (Google Earth) Offshore Baja-CA |
No. 18
PREDICTED M3.5 Expected Date/Location Original prediction 20 Apr '08 20-30 Apr (UTC) '08 Predicted at 0042 hrs UTC (time window open to 30 April, plus ≈1 day margin) Probability of event >85% within ≈250 km of Los Angeles
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REVISION nil |
| OBSERVED M4.1 Observed Date/Location Magnitude accuracy 85.4% 23 April, 34.866° 116.340° Predicted 3 days ahead 179 SW of Las Vegas (USGS) 195 km NE of Los Angeles (Google Earth) Southern California |
No. 17
PREDICTED M3.8 Expected Date/Location Original prediction 6 Apr '08 6-8 Apr (UTC) '08 Predicted at 2332 hrs UTC (time window open to 16 April, plus ≈1 day margin) Probability of event >90% within ≈250 km of Los Angeles
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REVISION nil |
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OBSERVED M3.6 Observed Date/Location |
No. 16
PREDICTED M3.5 Expected Date/Location Original prediction 24 Mar '08 24-26 Mar (UTC) '08 Predicted at 0450 hrs UTC (time window open to 3 Apr, plus ≈1 day margin) Probability of event >90% within ≈250 km of Los Angeles
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REVISED to M3.2 Expected Dates Upgraded range M2.8-M3.8 |
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OBSERVED M3.0 Observed Date/Location Magnitude accuracy 93.8% 27 March, 04:28:49, Lat 33.63° Lon -117.9° Predicted 3.4 hours ahead 57 km SE of Los Angeles Civic Centre Greater Los Angeles Area |
No. 15
PREDICTED M3.7 Expected Date/Location Original prediction 9 Mar '08 9-19 Mar (UTC) '08 Predicted at 0604 hrs UTC (time window open 10 days to 19 Mar + 1 day margin) Probability of event >90% within 250 km of Los Angeles
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Revision nil
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OBSERVED M3.9 Observed Date/Location Magnitude accuracy 94.9% 9 March at 09:22:31 hrs Predicted 3.3 hrs ahead of event 25 km NNW of Riverside Greater Los Angeles Area |
No. 14
PREDICTED M4.4 Expected Date/Location Original prediction 23 Feb '08 23-26 Feb (UTC) '08 Predicted at 0302 hrs UTC (time window open 10 days to 4 Mar) Probability of event >90% within 250 km of LA Civic Center
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REVISED to M4.2 Expected Date Revised at 0937 hrs on 4 Mar 4 Mar UTC Revised range M3.4-M4.6
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OBSERVED M3.7 Observed Date/Location Magnitude accuracy 88.1% 6 March at 00:14:26 hours Predicted 38 hours ahead Lat 34.298° Lon -116.858° Only 24 hrs outside window 131 km ENE of Los Angeles
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No. 13
PREDICTED M3.6 Expected Date/Location Original prediction 3 Feb '08 3-8 Feb (UTC) '08 Predicted at 0605 hrs UTC (time window open 10 days to 13 Feb) Probability of event >95% within 250 km of LA Civic Center |
REVISED to M3.3 Expected Date Revised at 0645 hours on 10 February 10-13 February
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OBSERVED M2.8 Observed Date/Location Magnitude accuracy 84.8% 12 February, Lat 33.25° Lon 115.66° Predicted 2 days ahead 148 ENE San Diego (subject to revision) Nr Obsidian Butte, CA |
No. 12
PREDICTED M4.0 Expected Date/Location Original prediction 24 Jan '08 24-29 January (UTC) '08 Predicted at 0146 hrs UTC (time window open 10 days to 2 Feb) Probability of event >90%
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REVISED to M3.5 Expected Date Revised Range M3.0-M4.0 1-2 February UTC Revised at 2107 hrs on 1 February
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OBSERVED M2.3 Observed Date/Location Magnitude accuracy 65.7% 2 February at Lat 32.14, Lon -116.45 34 km NNE Esenada, Baja CA |
No. 11
PREDICTED M3.5 Expected Date/Location Original prediction 10 Jan '08 10-20 January (UTC) '08 Predicted at 0422 hrs UTC (time window open 10 days to 20 Jan) Magnitude Range M3.2-M3.8 |
REVIEWS nil
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OBSERVED M3.8 Observed Date/Location Magnitude accuracy 92.1% 11 January Lat 35.34, Lon -188.55 Predicted 1 day ahead 320 km NE from San Diego Nr Bakersfield, Sth CA |
No. 10
PREDICTED M3.8 Expected Date/Location Original prediction 12 Dec '07 12-15 December (UTC) '07 Predicted at 0545 hrs UTC (time window open 10 days to 22 Dec) Probability of event >90% within 400 km radius of San Diego |
REVISION nil
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OBSERVED M4.5 Observed Date/Location Magnitude accuracy 84.4% 20 December '07 Predicted 8 days ahead Lat 31.75, Lon -116.27, 112 km SE of Tijuana Baja California M4.0 also in Greater LA on 19 December |
No. 9
PREDICTED M3.8 Expected Date/Location Original prediction, 17 Nov '07 17 November (UTC) '07 Predicted at 0320 hrs UTC time window open 10 days to 27 Nov Probability of event >90% within a 400 km radius of San Diego |
REVISED to M4.1 Expected Date Revised at 0115 hrs on 27 Nov 27 November '07 Upgraded range M3.8-M4.2 (Time window closes on 27 Nov) Location: Baja or Gulf of CA? |
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OBSERVED M3.3 Observed Date/Location Magnitude accuracy 80.5% 27 November '07 Largest quake in the 10-day window Baja California, Mexico 70 km SSW of Calexico, CA Lat 32.11, Lon -115.83 NOTE: M4.1 only one day later in Baja, CA This exact magnitude was predicted 21.5 hrs earlier on 27 Nov as per the above revised section of the table, but is not recorded above because it fell outside the time window of 10 days. This quake came at 22:49:29 hrs UTC on 28 Nov at 184 km SE of Tijuana, Baja CA.
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No. 8 (Predicted at 0240 hrs UTC on 4 November, 2007)
See red updates in table (revised 0100 hrs on 14 November)
PREDICTED M3.6 (Downgraded from M4) Range M3.5-3.7 (Range was M3.8 - M4.2) |
Expected Date/Location Over 1 day later than expected Southern California Region Between Lats 32-34° seems likely |
OBSERVED M3.0 Magnitude accuracy 83.3% Predicted 10 days in advance, and although later than expected it was the largest quake since Oct 29 |
Observed Date/Location 15 November 2007, only 37.5 min into new day Nr Weldon, CA, 153 km N of Los Angeles Lat 35.43, Lon -118.30 |
No. 7 (Predicted at 0130 hrs UTC on 16 October, 2007)
Revision of maximum level (M5.4) made at 0940 hrs on 16 October.
| PREDICTED M4.9 Probability of event >90% Range M4.0 - M5.4 |
Expected Date/Location Southern California Region |
OBSERVED M4.2 Magnitude accuracy 85.7% Predicted about 7 hrs ahead |
Observed Date/Location 16 Oct 07' 67 km ENE of Los Angeles, California Lat 34.38, Lon -117.64
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No. 6 (Predicted at 0100 hrs UTC on 15 October, 2007)
| PREDICTED M3.6 Probability of event >90% Range M3.5 - M3.8 |
Expected Date/Location Southern California Region |
OBSERVED M3.1 Magnitude accuracy 86.1% |
Observed Date/Location Lat 33.71, Lon -116.84 |
No. 5 (Predicted on 13 October, 2007)
| PREDICTED M2.3 Probability of event >90% Range M2.2 - M2.4 |
Expected Date/Location Southern California Region |
OBSERVED M2.2 Predicted one day ahead |
Observed Date/Location 15 Oct, 10 km SE Littlerock, CA Lat 34.47, Lon -117.90 |
No. 4 (Predicted on 5 October, 2007)
| PREDICTED M4.0 Probability of event >90% Range M4.0 - M4.2 |
Expected Date/Location Southern California Region |
| OBSERVED M4.2 Magnitude accuracy 95.2% Predicted 2 days ahead |
Observed Date/Location 7 Oct '07, Baja California, Mexico Lat 24.023, Lon -109.89 |
No. 3 (Predicted on 2 October, 2007) No
o
| PREDICTED M4.5 Probability of event >90% Range M4.3 - M4.6 |
Expected Date/Location Southern California Region |
| OBSERVED M4.4 Magnitude accuracy 97.8% Predicted 1 day ahead |
Observed Date/Location 3 Oct '07, Baja CA Sur, Mexico Lat 24.05, Lon -109.91 |
No. 2 (Predicted on 15 August, 2007) No
| PREDICTED M3.6 Probability of event >90% Range M3.6 - M4.2 |
Expected Date/Location Southern California |
| OBSERVED M3.5 Magnitude accuracy 97.2% Predicted 1 day ahead |
Observed Date/Location 16 Aug '07, Greater Los Angeles Lat 34.32, Lon -118.61 |
No. 1 (Predicted on 13 August, 2007)
| PREDICTED M2.8 Probability of event >85% Range M2.7 - M2.9 |
Expected Date/Location |