Wednesday, September 12, 2007

Today, there was a major earthquake very close to Bengkulu (~130km) (Sumatra/Indonesia) around 18:10 (WIB/GMT+7). As seen on the ShakeMap below [source USGS], it could be felt even in Jakarta, that is around 620km away!

The scale of the earthquake is difficult to comprehend, just notice the huge area of the Sumatra island that was affected. Actually, it was a string of multiple strong earthquakes in the area. Almost two hours later, there was another magnitude 5.7 earthquake in the same region:

And another one at 21:40 (GMT+7/WIB). I must also mention about the SMS based earthquake information system that I developed - sorry for boasting. After almost one year of testing, optimisation etc. it really worked well. The first SMS was sent to subscribers on 18:24:49 (WIB), that is only 14 minutes after the quake. From the user perspective it was like that, I was on the car and noticed lots of people going out of office buildings, something that looked like evacuation, so I wonder what was going. Within few minutes I already got details of the earthquake in SMS message. The precise message was "GREAT earthquake (M8.0) occurred on 12-Sep 18:10:19 WIB 146km (SW) from Bengkulu (Sumatera), 416km (SSE) from Padang (Sumatera).", or for Indonesian language subscribers "Gempa berkategori !! SANGAT BESAR (M8.0) terjadi 12-Sep 18:10:19 WIB 146km (SW) dari Bengkulu (Sumatera), 416km (SSE) dari Padang (Sumatera)". Most people working in tall buildings in Jakarta got really scared as you could really feel building swaying, or even see furniture shaking. I was on the car that time so I didn't feel much. The great thing about informing about earthquakes via SMS, is that after I received SMS informing about earthquake, it took another 10 minutes for any radio station to inform where was the earthquake. Every station just reported that there was an earhtquake felt in Jakarta, but none could specify where - and I already had this information delivered to my mobile phone. I think all this worked really well and I'm quite happy to see it functioning. The only issue was that some of the users called complaining about receiving 3 messages informing about earthquake, while they expected one. The reason for this was simple, there actually was more than one erthquake in the area and system decided to report all, because the magnitude was above 7 - in application everything above magnitude 7 is reported, even if similar earthquake was already reported. Obviously, the application does not report all earthquakes in Indonesia as it would sent more than 10 SMS a month, it only reports the earthquakes that are somehow important. FYI it took one year of optimisation to make all this work well and systems sends now from 4 to 5 SMS a month. Anyway, if you live in Indonesia and are interested to subscribe, simply sends SMS with content "REG EARTHQUAKE" or "REG GEMPA" (for Indonesian language version) to number 6768 - works with all subscribers, and when there's earthquake anywhere in Indonesia, you should know details within 15 to 45 minutes (depending on magnitude and location), that is often lot faster than you'll hear anything from TV or Radio! - the cost Rp1000 per received SMS (~US$0.10).

Update: I got information from Radio Elshinta 90,00 FM that out of 4 systems that should warn about possible tsunami (there was a risk of tsunami here), none worked! So much money put into this by various government agencies after the Sumatra tsunami, and not a single tsunami warning system worked and warned about possible tsunami - can you imagine this? I'd just say that they all are really lucky that this time there was no tsunami, otherwise lots of people would lose their lives for incompetence of people responsible for this.

Update: Quoted from news "The National Weather Service’s Pacific Tsunami Warning Center said sea level readings showed that the earthquake, which had a magnitude of 8.2, did indeed generate a tsunami, and that it may have caused destruction along the coast. A wave of up to 9 feet was reported to have hit Padang about 20 minutes after the quake, said Suhardjono, an official with Indonesia’s meteorological agency, the A.P. reported. But there had been no sightings of strong tidal waters two hours after the earthquake, usually the critical time for the formation of a tsunami.". Unfortunately, what I've wrote in my first update was not accurate. There was a tsunami after the earthquake. Now, I just wonder what government will do considering the fact that none of the four systems that was supposed to warn about tsunami worked. Let me guess, KKN?


KKN - indonesian term for corruption, collusion, and nepotism.


Anonymous said...

Hi Marek. I work for telco company and use your SMS warning system. It's always good to know fast about any gempa that could damage our BTS'. A friend of mine works for insurance company and lots of people use it there too to know fast about earthquake and act faster. You should work with Indonesian government to implement this system for every telco.

Anonymous said...

Hello Marek, I've subscribed to your SMS based earthquake information system and just today (2007-09-14) earthquake happened atSumatra Island ( but I receive no SMS from the system, is there something wrong in it? Thanks...

Marek Bialoglowy said...

Hi. Good question. The earthquake you mentioned was magnitude 6.4 and as you can observe on shakemap provided by USGS, it could not cause any damage in Bengkulu (120km away) area. Since there was a constant string of earthquakes over two days, application automatically increased threshold for reporting earthquakes in the area of Sumatra, which at the time of earthquake was set to magnitude 6.5 (0.1 higher than 6.4 earthquake you mentioned) and will likely go lower to 6 in few hours.

Overall, if we would report all aftershocks, the system would have to distribute more than 20 SMS to each user since first earthquake, and unfortunately we see that users get upset if they got more than 5 SMS a day, even if there were simply so many earthquakes. So, now the reporting application automatically increases reporting threshold for earthquakes whenever it feels earthquake is not important to report, likely in situations where it is an aftershock and risk of damage is low. However, any earthquake above magnitude 7.0 is reported, even as aftershock as minimum magnitude with risk of tsunami is magnitude 7.3. So, to be sure that all this is reported we simply always distribute anything above magnitude 7.0.

If you somehow would like to receive all earthquakes, even if it can be considered as aftershock I can manually subscribe you to service without a threshold. Just drop me your phone number in an e-mail. However, I must warn you that if there's a major earthquake with aftershocks, you can get 10-15 SMS (Rp1000/SMS).

Marek Bialoglowy said...

BTW I personally think that for BMG to report that 6.5 magnitude earthquake in that region has a potential for tsunami is a wrong thing to do. Even with magnitude 6.9, the tsunami could be maximum 50cm tall (likely only 20cm), so in my opinion the damage caused by panic is higher than the one of a 50cm tsunami. Well, and actually it was not 6.9 but only 6.4. I'm not an expert, but I think they should issue alerts only when earthquake is minimum magnitude 7. From my observations, none of the earthquakes <7.0 that BMG reported as having potential for tsunami actually caused noticable tsunami, so my question is why they still continue to issue invalid reports and just scare people for no reason.

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