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Earthquake Predictions
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Torres del Paine National Park, Chile © 2006 David Mathies, iStock Photos, Inc.All rights reserved
THE CHILE REGION
(1) NORTHERN REGION - centered on Antofagasta
Earthquake forecasts for this region are restricted to a circular area of 500 km radius centered on Antofagasta at latitude -23.624°, longitude -70.402°. This region has experienced
62 strong (M6.0-6.9), 9 major (M7.0-M7.9), and one great earthquake of magnitude 8.0 since the beginning of 1975.
(USGS/NEIC and Google Earth sources)
(2) CENTRAL REGION - centered on Santa Cruz
Earthquake forecasts for this region are restricted to a circular area of 500 km radius centered on Santa Cruz at latitude -34.634°,
longitude -71.359°. This region was added after the great M8.8 earthquake of February 27, 2010, and since 1975 the region has also experienced 52 strong, and 7 major earthquakes.
(USGS/NEIC and Google Earth sources)
All earthquake predictions for the Chile Region are for the largest earthquake in the 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, 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.
CHILE REGION
See also Long-term Forecasts
These Long-term Forecasts now give the approximate timing of the largest regional earthquakes for the lunar month 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. 19
PREDICTED M5.9 Expected Date/Location This revision 30th June* 30 June - 3 July (UTC) 2009 Predicted at 0727 hrs UTC (time window open to 6th July +1 day margin) Probability of event >90% within ≈500 km of Calama, Chile *Original prediction for M6.0 was made 20th June in table for Long-term Forecasts |
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OBSERVED M5.0 Observed Date/Location |
No. 18
PREDICTED M5.0 Expected Date/Location Original prediction 14th April 14-24 April (UTC) 2009 Predicted at 1230 hrs UTC (time window open to 24th April +1 day margin) Probability of event >90% within 500 km of Antofagasta
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OBSERVED M6.0 Observed Date/Location |
No. 17
PREDICTED M4.6 Expected Date/Location Original prediction 7th March 7-10 March (UTC) 2009 Predicted at 0704 hrs UTC (time window open to 10th March) Probability of event >85% within 300 km of Antofagasta, Chile
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| OBSERVED M4.7 Observed Date/Location Magnitude accuracy 97.9% 9th March at Lat -23.08 Lon -68.98 Predicted two days ahead 70 km S of Calama, Antofagasta (EMSC source) Antofagasta Region |
No. 16
PREDICTED M5.7 Expected Date/Location Original prediction 27 Jan 27-31 January (UTC) 2009 Predicted at 1038 hrs UTC (time window open to 5th February) Probability of event >85% within 300 km of Antofagasta, Chile
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| OBSERVED M5.1 Observed Date/Location Magnitude accuracy 89.5% 31st January at Lat -22.88 Lon -69.864 Predicted 4 days ahead 100 km NNE of Antofagasta (USGS source) Antofagasta, Chile |
No. 15
PREDICTED M5.0 Expected Date/Location Original prediction 11 January 17 January +/-3 days (UTC) 2009 Predicted at 0447 hrs UTC (time window open to 21 January) Probability of event >90% within 300 km of Antofagasta, Chile
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REVISION nil |
| OBSERVED M4.2 Observed Date/Location Magnitude accuracy 84% 15th January at Lat -22.30 Lon -70.18 Predicted 4 days ahead 131 km W from Calama (EMSC source) Antofagasta, Chile |
Previous tables have been deleted to save space
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