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Earthquake Predictions
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'City at dusk' © hywit dimyadi, iStockphotos Inc. All rights reserved
THE JAVA REGION is re-defined (02-25-08) as all areas within ≈500 km radius* of Semarang, at latitude -6.97° and longitude 110.43°. This region covers all of Java to the tip of Bali.
*The radius is 500 km plus an ≈10% error margin of about 50 km to include some events that may occur close to the nominated boundary of the region.
Previously, for the purpose of these predictions, the Java Region was much larger and with a radius of 1000 km from Malang, extending from the tip of Sumatra to the Island of Sumba.
All earthquake predictions for the Java Region are for the
largest earthquake in the 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 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.
JAVA REGION
No. 9
PREDICTED M5.5 Expected Date/Location Original prediction 24 June 24-30 June (UTC) 2008 Predicted at 0448 hrs UTC (time window open to 2nd July, plus ≈1 day margin) Probability of event >90% within ≈500 km of Semarang
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| OBSERVED M4.8 Observed Date/Location Magnitude accuracy 87.3% 3rd July at Lat -6.90 Lon 105.99 Predicted 10 days ahead 175 W from Bandung Sunda Strait, Java |
No. 8
PREDICTED M5.8 Expected Date/Location Original prediction 22 Apr '08 22 Apr-2 May (UTC) '08 Predicted at 2238 hrs UTC (time window open to 2 May, plus ≈1 day margin) Probability of event >90% within ≈500 km of Semarang
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REVISION nil |
| OBSERVED M5.0 Observed Date/Location Magnitude accuracy 86.2% 27 April, Lat -7.68° Lon 107.91° Predicted 5 days ahead 215 SE of Jakarta, Java |
No. 7
PREDICTED M4.5 Expected Date/Location Original prediction 8 Apr '08 8-10 Apr (UTC) '08 Predicted at 0017 hrs UTC (time window open to 18 April, plus ≈1 day margin) Probability of event >85% within ≈500 km of Semarang
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REVISION nil
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OBSERVED M4.6 Observed Date/Location
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No. 6
PREDICTED M5.0 Expected Date/Location Original prediction 24 Mar '08 25-29 Mar (UTC) '08 Predicted at 1936 hrs UTC (time window open to 3 Apr, plus ≈1 day margin) Probability of event >85% within ≈500 km of Semarang
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REVISIONS nil |
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OBSERVED M5.0 Observed Date/Location Magnitude accuracy 100% 31 March, Lat -9.39° Lon 111.92° (EMSC) Predicted 7 days ahead 149 km S of Blitar, JAVA
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No. 5
PREDICTED M5.3 Expected Date/Location Original prediction 10 Mar '08 10-20 March (UTC) '08 Predicted at 1045 hrs UTC (time window open 10 days to 20 Mar + 1 day margin) Probability of event >85% within 500 km of Semarang
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REVIEWS nil
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OBSERVED M4.3 Observed Date/Location Magnitude accuracy 81.1% 16 March, Lat -8.84° Lon 112.47° (EMSC) Predicted 6 days ahead 92 km S from Blitar, Java |
No. 4
PREDICTED M5.9 Expected Date/Location Original prediction 25 Feb '08 25 Feb-7 Mar (UTC) '08 Predicted at 0536 hrs UTC (time window open 10 days to 7 Mar) Probability of event >90% within 500 km of Semarang
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REVISED to M5.5 Expected Dates Revised 28 Feb at 2218 hrs 28 Feb -7 Mar UTC Revised range M4.5-M6.0
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OBSERVED M4.8 Observed Date/Location Magnitude accuracy 87.3% 3 March, Lat -7.56° Lon 106.60° Predicted 4 days ahead 77 km S from Cibadak Java, Indonesia |
No. 3
PREDICTED M6.2 Expected Date/Location Original prediction 30 Jan '08 30 January - 2 February (UTC) '08 Predicted at 2007 hrs UTC (time window open 10 days to 8 Feb) Probability of event >74%
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REVISED to M6.0 Expected Date Revision at 0517 hrs on 4 Feb 4-8 February UTC Revised Range M5.4-M6.4
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OBSERVED M5.7 Observed Date/Location Magnitude accuracy 95.0% 7 February at Lat 7.54, Lon 116.82 Predicted 3 days ahead 1125 km E from Jakarta in Bali Sea Bali Sea, Java Region |
No. 2
PREDICTED M5.2 Expected Date/Location Original prediction 10 Jan '08 10-20 January (UTC) '08 Predicted at 0955 hrs UTC (time window open 10 days to 20 Jan) Magnitude Range M4.7-M5.7 |
Reviews nil
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OBSERVED M5.0 Observed Date/Location Magnitude accuracy 96.2% 11 January 10.70 S, 113.31 E Predicted 1 day ahead 264 km S of Ambulu (EMSC record) South of Java
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No. 1
PREDICTED M6.9 Expected Date/Location Original prediction 17 Dec '07 17-19 December (UTC) '07 Predicted at 0320 hrs UTC (time window remains open 10 days to 27 Dec)
Magnitude Range M6.5-M7.0 Java Region Probability of event >67% In the Java Trench South of Java? |
REVISED to M5.9 Expected Date/Location Revision at 1115 hrs on 20 Dec 20-27 December UTC Magnitude range M5.4-M6.3 Java Region
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OBSERVED M5.3 on 24 December '07 Lat -4.24, Lon 101.27 Outside Java zone by some 450 km Southern Sumatra |