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Earthquake Predictions
Sumatra Region |
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© C K Lai, iStock photos Inc. All rights reserved.
Banda Aceh Tsunami damage. This is the worst hit stretch of Banda Aceh. Houses are all gone. Some survivors staying in tents.
THE SUMATRA REGION is newly defined (02-24-08)
and subdivided as follows:
(1) Northern Sumatra - areas within ≈500 km radius* of Medan. This region, centered on Medan at Lat 3.59° and Lon 98.67°, extends from offshore Banda Aceh down through Simeulue to the Nias Region.
(2) Southern Sumatra - areas within ≈500 km radius* of a center point (Lat -3.60°, Lon 102.14°) at Lubuktandjung on the coast, which is 350 km SE of Padang.
This region includes the very seismically active Kepulauan Mentawai area and
extends from southern Nias down to the tip of Java across the Sunda Strait.
*The radius is 500 km for each of the above areas, plus an ≈10% error margin of 50 km in order to include events close to the nominated boundary of each region.
All earthquake predictions for Sumatra 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.
SUMATRA REGIONS
Two tables may be current, so please scroll down.
See also Long-term Forecasts
No. 22 Northern Sumatra
PREDICTED M6.3 Expected Date/Location Original prediction 23 June 23-25 June (UTC) 2008 Predicted at 2138 hrs UTC time window open to 2nd July Probability of event >85% within ≈500 km of Medan
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| OBSERVED M5.6 Observed Date/Location Magnitude accuracy 88.9% 25 June at Lat 1.39 Lon 97.21 Predicted two days ahead 290 SSW from Medan Northern Sumatra |
No. 21 Northern Sumatra
PREDICTED M5.4 Expected Date/Location Original prediction 19 Apr '08 19-29 Apr (UTC) '08 Predicted at 2354 hrs UTC (time window open to 29 April, plus ≈1 day margin) Probability of event >90%
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REVISION if needed is posted here
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| OBSERVED M5.0 Observed Date/Location Magnitude accuracy 92.6% 19 April at 1857 hrs, Lat 2.73° Lon 94.55° Predicted 5 hours ahead 325 km S from Banda Aceh Off W Coast Nth Sumatra |
No. 20 Southern Sumatra
PREDICTED M5.3 Expected Date/Location Original prediction 20 Apr '08 20-30 Apr (UTC) '08 Predicted at 0104 hrs UTC (time window open to 30 April, plus ≈1 day margin) Probability of event >90% within ≈500 km of Lubuktandjung
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REVISION if needed is posted here
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| OBSERVED M5.3 Observed Date/Location Magnitude accuracy 100% 27 April, Lat -3.422° Lon 101.222° Predicted 7 days ahead 120 km WNW of Bengkulu (USGS) Southern Sumatra |
No. 19 Northern Sumatra
PREDICTED M5.0 Expected Date/Location Original prediction 8 Apr '08 8-15 Apr (UTC) '08 Predicted at 0027 hrs UTC (time window open to 18 April, plus ≈1 day margin) Probability of event >85% within ≈500 km of Medan
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REVISION nil
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OBSERVED M5.1 Observed Date/Location |
No. 18 Southern Sumatra
PREDICTED M4.8 Expected Date/Location Original prediction 8 Apr '08 8-15 Apr (UTC) '08 Predicted at 0023 hrs UTC (time window open to 18 April, plus ≈1 day margin) Probability of event >85%
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REVISION nil
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OBSERVED M4.9 Observed Date/Location Magnitude accuracy 98.0% 17 April , Lat -5.903° Lon 105.488° (USGS) |
No.17 Northern Sumatra
PREDICTED M6.2 Expected Date/Location Original prediction 21 Mar '08 21-22 Mar (UTC) '08, open to 31 Mar Predicted at 0214 hrs UTC ( period: 10 days to 31 Mar plus ≈1 day margin) Probability of event >75% within ≈500 km of Medan
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REVISED to M5.4 Expected Dates Revised at 0432 hrs on 23 March 23 -31 March, plus ≈1 day margin Probability of event >90% Updated range M5.0-M6.0
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OBSERVED M6.3 Observed Date/Location Magnitude accuracy 85.7% 29 March, Lat 2.91° Lon 95.28° Predicted 6 days ahead 380 km W from Medan Simeulue, Off Nth Sumatra |
No.16 Southern Sumatra
PREDICTED M5.5 Expected Date/Location Original prediction 24 Mar '08 24-26 Mar (UTC) '08 Predicted at 0222 hrs UTC (time window open to 3 Apr, plus ≈1 day margin) Probability of event >85%
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REVISION nil
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OBSERVED M5.7 Observed Date/Location Magnitude accuracy 96.5% 2 April, Lat -4.38° Lon 102.67° (USGS) Predicted 9 days ahead 80 km SSE of Bengkulu Southern Sumatra
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No.15 Southern Sumatra
PREDICTED M6.4 Expected Date/Location Original prediction 12 Mar '08 12-13 Mar (UTC) '08 Predicted at 0119 hrs UTC (time window open 10 days to 22 Mar + 1 day margin) Probability of event >70%
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REVISED to M5.0 Expected Dates Revised at 0038 hrs on 15 March 15-22 March (+ 1 day error margin) Updated range M4.5-M5.5 Probability of event >85%
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OBSERVED M5.3 Observed Date/Location Magnitude accuracy 94.3% 16 March, Lat -2.93° Lon 101.013° Occurred at 23:05:27 hrs UTC 230 km SSE from Padang Predicted 46.5 hrs ahead Southern Sumatra
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No. 14 Northern Sumatra
PREDICTED M6.6 Expected Date/Location Original prediction 6 Mar '08 6-8 Mar (UTC) '08 Predicted at 1035 hrs UTC (time window open 10 days to 16 Mar) Probability of event >75% within 500 km of Medan
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REVISED to M5.2 Expected Dates Revised at 1945 hrs on 11 Mar 11-16 March Probability of event >85% within 500 km of Medan Updated range M4.5-M5.5 Northern Sumatra
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OBSERVED M6.0 Observed Date/Location Magnitude accuracy 86.7% 15 March, Lat 2.82° Lon 94.590° Predicted 4 days ahead 460 km W of Medan Source USGS - Mw 6.0 Off W Coast , Nth Sumatra Source EMSC - Mw 5.9
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No. 13
PREDICTED M5.4 Expected Date/Location Original prediction 24 Feb '08 24 Feb-5 Mar (UTC) '08 Predicted at 2222 hrs UTC (time window open 10 days to 5 Mar) Probability of event >90% within 500 km of Medan
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REVISION nil
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OBSERVED M5.2 Observed Date/Location Magnitude accuracy 96.3% 5 March, Lat 5.076 ° Lon 94.826° Predicted 10 days ahead 75 km SW of Banda Aceh Off Coast of Northern Sumatra |
No. 12
PREDICTED M5.8 Expected Date/Location Original prediction 24 Feb '08 24 Feb-5 Mar (UTC) '08 Predicted at 2222 hrs after M6.4 event (time window open 10 days to 5 Mar) Probability of event >90% (see new definition of area above)
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REVISION nil
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OBSERVED M7.0 Observed Date/Location Magnitude accuracy 82.9% 25 February, 0836 hrs, Lat -2.37° Lon 100.02° Predicted 10 hours ahead 160 km SSW of Padang |
No. 11
PREDICTED M6.9 Expected Date/Location Original prediction 12 Feb '08 12-14 February (UTC) '08 Predicted at 2234 hrs UTC (time window open 10 days to 22 Feb) Probability of event >75%
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REVISED to M6.5 Expected Date/Location Revised 0512 hrs on 14 February UTC 14-22 February Updated range M5.5-M7.0 Sumatra Region
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OBSERVED M7.4 Observed Date/Location Magnitude accuracy 87.8% 20 February, Lat -2.77° Lon 95.97° Predicted 8 days ahead 310 km SSE Banda Aceh Simeulue, Sumatra |
No.10
PREDICTED M6.4 Expected Date/Location Original prediction 31 Jan '08 4-9 February (UTC) '08 Predicted at 1119 hrs UTC (time window open 10 days to 9 Feb) Probability of event >74% Near Nias to Banda Aceh Region?
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REVISED to M6.3 Expected Date Revised at 0035 hrs on 7 Feb 7-9 February, UTC Northern Sumatra |
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OBSERVED M5.5 Observed Date/Location Magnitude accuracy 87.3% 12 February, 2 days or 49.5 hrs late Predicted 5 days ahead Southern Sumatra
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No. 9
PREDICTED M6.5 Expected Date/Location Original prediction 17 Jan'08 17-27 January (UTC) '08 Predicted at 2050 hrs UTC (time window remains open 10 days to 27 Jan) Magnitude Range M6.0-M7.0 Kep. Mentawai - Simeulue? Probability of event >70% Sumatra Region |
REVISION nil
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OBSERVED M6.2 Observed Date/Location Magnitude accuracy 95.4% 22 January, Lat 1.01 N, Lon 97.43 E Predicted 5 days ahead Nias Region, Sumatra
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No. 8
PREDICTED M6.9 Expected Date/Location Original prediction 4 Jan '08 4-8 January (UTC) '08 Predicted at 0850 hrs UTC (time window remains open 10 days to 14 Jan) Magnitude Range M6.3-M7.5 Probability of event >67% Sumatra Region Kep Mentawai area? |
REVISED to M5.5 Expected Date/Location Revised at 2327 hrs on 12 January 12-14 January '08 (UTC) Updated range M5.0-M6.3 Sumatra Region |
| OBSERVED M5.8 Observed Date/Location Magnitude accuracy 94.8% 14 January '08 Lat 10.42, Lon 92.94 Predicted 2 days ahead Andaman Islands The Andaman Islands region in the Indian Ocean is defined at the top of this page as part of the so-called Sumatra Region, highlighted by the great Sumatra-Andaman earthquake. |
No. 7
PREDICTED M6.6 Expected Date/Location Original prediction 20 Dec '07 20-24 December (UTC) '07 Predicted at 1138 hrs UTC (time window remains open 10 days to 30 Dec) Magnitude Range M6.2-M7.0 Probability of event >67% Sumatra Region |
REVISION nil
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| OBSERVED M5.8 Observed Date/Location Magnitude accuracy 87.9% 22 December '07 Lat 2.09, Lon 96.86 Predicted 2 days ahead Simeulue, Indonesia |
No. 6
PREDICTED M6.4 Expected Date/Location Original prediction 9 Dec '07 9-12 December (UTC) '07 Predicted at 1955 hrs UTC (time window open 10 days to 19 Dec) Probability of event >80% Simeulue Region? |
REVISED to M6.0 Expected date/Location Revised at 0130 hrs UTC on 12 Dec 12-19 December '07 Updated range M5.5-M6.5 Kep Mentawai Region? |
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OBSERVED M5.0 Date/Location Magnitude accuracy 83.3% 12 December '07 at 03:43:57 Predicted 3 days ahead Lat 4.45 S, Lon 100.85 E 390 km S of Padang SW of Sumatra
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No. 5
PREDICTED M6.9 Expected Date/Location
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