Very dangerous shallow earthquake below Sulawesi, Indonesia

Lake Matano, Sulawesi, Indonesia greater earthquake area - Panoramio picture courtesy John Adamson -

UPDATE 19/02 “ 16:29 UTC : Mike Hannah reported this morning via facebook the following on Soroako : Power restored to expat residential area 45 hours after quake.The hydro dams power the mine and smelter. The third hydro dam [the lowest] is only a few km from Malili and is presently under construction. FB contacts reporting aftershocks 2 days after. No word on mine infrastructure (Western designed kit which would have had proper design, so should be fine).

UPDATE 18/02 “ 23:55 UTC : Malili seems to have been hit the hardest with a number of collapsed houses and damage to fences, awnings, cracks in houses etc. NO injuries have been recorded.
Early February 18, the power was not yet restored in Soroako.

UPDATE 17/02 “ 14:25 UTC : Mike Hannah wrote to us via Facebook that he had a call with someone working in Soroako. He confirmed that there were NO reports of casualties or injuries.  The power in the residential housing areas near the mine is not restored yet.

UPDATE 16/02 - 18:39 UTC : The updates and follow-up of the aftermath of this earthquake looks to be a "earthquake-report world exclusive" (if we exclude the Indonesian press of course 🙂 ).
After reports in the International press right after the quake, the non-Indonesian press went silent.

UPDATE 16/02 - 17:11 UTC : USGS reports a moderate aftershock of 4.7 at a depth of 33 km. The epicenter location of the aftershock is more to the North-East of the lake, approx. in the middle between Lake Matano and the Banda Sea.
There are much more aftershocks than this one, but most of them were weaker.

UPDATE 16/02 - 16:58 UTC : The Indonesian news channel Tempo reported that hundreds of people ran to the higher grounds of the Sorowako airport when the earthquake struck yesterday evening (local time) fearing for a lake tsunami. The local people told reporters that the shaking lasted for approx. 1 minute. Most people were enjoying dinner when the shaking started.
So far no casualties were reported. However, a dock on Lake Towuti vanished (probably by the shaking).
The first damage inspection survey in the greater epicenter area revealed that hundreds of houses are left with cracks in the wall, many school buildings area also damaged.
Some houses are reported collapsed in the Malili district, approx. 30 km from Sorowako.
Sorowako residents are still scared. Officials did inform local people not to believe in the rumors of a potential lake tsunami.

UPDATE 16/02 - 12:07 UTC : Arisa Asrul writes from the epicenter area @ Sorowako :
Since 12pm (Indonesian timezone), there a few small shake in Sorowako, when i write this a minute ago i felt a a small shake, do you have any information about, several people still live in open area because they got rumor about middle of the night will occur a big earthquake.
Earthquake-report answer : Rumors on a big coming earthquake are ridiculous. Please tell them.
Earthquakes are UNPREDICTABLE.
Of course, after an earthquake like yesterday, a lot of aftershocks can scare people a lot. Most of the time aftershocks are always smaller than the mainshock, however even that cannot be predicted. In some cases they can indeed be stronger, but nobody can predict that. BMKG, USGS, EMSC etc, the biggest organizations in the world cannot predict the magnitude of an upcoming earthquake.
The current aftershocks may go on for days, weeks and even months, but normally the frequency will go down and the magnitude in average also. Some major aftershocks are still possible. The February 27 2010 massive earthquake in Chile still generates aftershocks today.

UPDATE 16/02 - 09:40 UTC : Padli was also in Soroako and he wrote Earthquake-Report :
I am @ Soroako now. We had felt some series of shakes last night started from around 21.30 local time. Until now (16 Feb, 12:07 PM) , several shakes still happening. Rumor says some building were damaged and nickel mining activities were interrupted. Last night earthquakes made thousand of people flew out of home and stayed outside until around 3 AM. (this update came in as a comment below this article)

UPDATE 16/02 - 09:30 UTC : Reports of cracked houses, evacuations and business interruptions are labeling this earthquake as a CatDat Orange until a full damage report is established.

UPDATE 16/02 - 00:40 UTC : Finally a Felt and experience report from the nearest location to the epicenter, Soroako or Sorowako.
Paul Nikkel was in Sorowako during the quake “ no damages aside from power outage and no injuries as far as I am aware.

UPDATE 23:55 UTC : 9 hours after the earthquake we have still NOT seen any news from Soroako, the city at approx. 20 km from the epicenter.
Sulawesi newspapers are only mentioning scared people and power outages after the quake in Poso.
Poso is about 150 km from the epicenter and thus cannot be compared with Soroako.
PT Inco the mining company has not yet  released a report on the earthquake. We expect that a report will be published soon.
Newspapers start to work again around this time in Indonesia (they mostly do not work during the night) and soon the final outcome will be known.

UPDATE 18:16 UTC : The earthquake was probably the result of a movement in the Matano fault (named after the lake).  There is still doubt whether today's earthquake is sideways or an up and down shift, most likely sideways.

UPDATE 17:10 UTC : If you are a user of Google News and a regular reader of Earthquake-Report, you may consider in telling Google news that it may be worthwhile to follow us. We have seen on various occasions (also today) that their sources are not always up to date.  Thanks for supporting us.

PT Inco mining pit in Soroako, Sulawesi Indonesia

UPDATE 16:44 UTC : Reports coming out of Poso did reveal NO damage to buildings. Poso is however NOT relevant for the final outcome of this earthquake as it is located at nearly 150 km from the epicenter.

UPDATE 16:31 UTC : Still NO direct news from the greater epicenter area. Earthquake-Report is following the aftermath of this earthquake by the means of many sources in Indonesia.

UPDATE 16:13 UTC : Positioning and measuring earthquake locations and earthquake energy is far from easy. Every agency has its own system and takes a lot of data into account to report a certain magnitude. The magnitude will always be an average of many stations.
Calculation of the epicenter location is also very difficult and has a substantial error margin of several kilometers. Felt reports of people living in the area are often giving another picture as measured by instruments.

The reasons for that will be explained in a special article we prepare for this subject.
In this particular case, the epicenter can be as it was reported by USGS. There is however also a possibility that the epicenter is more away from population into the wilderness or, on the bad site, closer to the settlements.
Let's hope for a more remote location in the wilderness.

UPDATE 15:59 UTC : Live Seismograph recorder of the February 15, 2011 earthquake in Sulawesi, Indonesia near Soroako.  Seismograph installed in Davao, Philippines.

UPDATE 15:52 UTC : BMKG (Seismology Indonesia) reported a 4.7 aftershock at 20:45 WIB. The epicenter of this aftershock was 18 km from Soroako and had  a depth of 30 km.

UPDATE 15:49 UTC : Indonesian people are hoping to get a fast sign of safety from 2 major places in the area : Soroako and Bungku (Central Sulawesi)

UPDATE 15:47 UTC : A ferry takes people in between Soroako and Nuha across Lake Matano. It is not known whether the ferry was transporting people on the lake. As it was 6:30 PM in the evening, probably not.

UPDATE 15:43 UTC : A lot of settlements are located at the northern border of the lake without any road passing by.
It looks like the only roads in the lake's area are those to reach the mining site of Soroako. The northern side of the lake has the steepest slopes.

UPDATE 15:41 UTC : Almost all the settlements in the area are bordering  Lake Matano.

UPDATE 15:36 UTC : Soroako has his own airfield with a runway of approx. 3500 ft following
An airport close to the epicenter is very important enabling rescue services to fly in equipment if needed.

UPDATE 15:33 UTC : We believe that PT Inco management in Soroaka will be the first to send out signals about eventual damage and/or injuries as they will have certainly satellite communications working on batteries.

UPDATE 15:30 UTC : PT Inco is an Indonesian mining company who has a number of mining pits and ore plants in Sulawesi (Celebes).
The company has also a dormitory hotel for its workers.
The indigenous population of Soroako are mostly farmers.

UPDATE 15:24 UTC : People fled out of their houses more than 100 km from the epicenter and are reluctant to return to them as they are scared for aftershocks.

UPDATE 15:17 UTC : Soroako or Sorowako is the location of one of the greatest open pit nickel mines in Indonesia. So far NO news yet out of Soroako.
Pt Inco's nickel mining operation in Sorowako is classified as open pit/cast mining

UPDATE 15:10 UTC : People in Palu, the capital of Central Sulawesi have reported that the shocks lasted for at least 20 seconds.

UPDATE  15:09 UTC : Power has been lost in Poso and Morawali, more than 100 km from the epicenter

UPDATE 14:53 UTC : Felt intensities from BMKG - Indonesian Geophysical Institute, Poso IV-V, II-III Luwuk, V Soroako, II-III Masamba, II-III Palopo, I-II Kendari,

UPDATE 14:50 UTC : Over 9000 people live in Soroako... mostly workers. NB: The Bahasa name is Sorowako.

UPDATE 14:45 UTC : Other towns in the near epicenter are Malili, Bungku, Dongin and Bahumbulu as well as Soroako. Still waiting for more substantial news from our indonesian sources. The epicenter is nearly exactly on the point of the border between
Central Sulawesi, SouthEast Sulawesi and South Sulawesi...

Jika Anda memiliki laporan gempa bumi, silahkan komentar di bawah ini.

UPDATE 14:44 UTC : There is nickel mining close to Soroako (PT Inco), which could be affected.

UPDATE 14:38 UTC : The epicenter area was also struck by other earthquakes like : 29.12.1828 - 30.07.1907 and 15.08.2002

UPDATE 14:36 UTC : Last year the 15th June 2010 at 23:53,  there was an earthquake on the other side of the island at North Mamuju, killing one person working at a sand quarry. The Magnitude was 5.1 Mw.

UPDATE 14:33 UTC : theoretical models can only be reasonably good when the data entered in them is also nearly correct. Earthquake data like magnitude, depth and epicenter location hace to be recalculated ny seismologists and can be rectified to + or + afterwards.

UPDATE 14:30 UTC : When we entered the earthquake data in another theoretical model, the result came out as max.  50 people might be injured. Fatalities 0 to 3.

UPDATE 14:25 UTC : Wikipedia description of Lake Matano in the immediate vicinity of the earthquake's epicenter : Lake Matano, also known as Matana, is a natural lake in South Sulawesi, Indonesia. It is the deepest lake in Indonesia (ranked by maximum depth), and the 10th deepest lake in the world.

UPDATE 14:19 UTC : Our theoretical models are predicting NO loss of live

UPDATE 14:17 UTC : GDACS automated systems have published a GREEN earthquake alert for this earthquake = very

limited chance on damage and/or injuries. Earthquake-Report does however NOT agree with GDACS as we find too many uncertainties in this earthquake.

UPDATE 14:15 UTC : As it is after dark in Sulawesi, it may take a long time before we will know the exact outcome of this very dangerous earthquake.

UPDATE 14:11 UTC : Based on the epicenter calculations of the USGS and the energy of this earthquake a severe shaking can be experienced by 1,000 people, very strong shaking by 4,000 people and a strong shaking by 314,000 people.

UPDATE 14:07 UTC : Although we have no names of the villages, on satellite pictures we can clearly see a number of settlements on the shores of Lake Matano and no more than 10 km from the epicenter (if the epicenter location is confirmed after recalculation).

At 9:33 PM local time, a very strong earthquake occurred below Sulawesi Indonesia. calls this earthquake very dangerous because of the shallow depth of the hypocenter (20 km).
There is NO risk for a tsunami as the epicenter is located on the island.

Most important Earthquake Data:
Magnitude : 6.1
UTC time :  Tuesday, February 15, 2011 at 13:33:53 UTC
Local time at epicenter : Tuesday, February 15, 2011 at 09:33:53 PM at epicenter
Depth (Hypocenter) : 20 km satellite map + I Did Feel It form
Geo-location(s) :
Although we have no names of the villages, on satellite pictures we can clearly see a number of settlements on the shores of Lake Matano and no more than 10 km from the epicenter (if the epicenter location is confirmed after recalculation).
255 km (158 miles) SE (133°) from Palu, Sulawesi, Indonesia

Links to important maps
USGS Did You Feel It Map
Google satellite map of the area showing the kind of terrain the earthquake took place
3-dimensional view of the earthquake area (USGS epicenter location)
USGS Shaking map
USGS historic earthquakes map
USGS impact on population map
USGS Seismic hazard map
LIVE SEISMOGRAM (Seismograph station of Davao, Philippines)
GDACS Green Earthquake Alert (Global Disaster Alert and Coordination System)

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a was also created by SOS Earthquakes. makes it easy to let the world know which shaking people have experienced during the earthquake. gives also the opportunity to write some additional text. Filling up the form takes only 1 minute. gives an overview of all the resent earthquakes and let you even go back in time and retrieve earthquakes of a certain date in the past. headlines on twitter
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  1. Due to it's size I am posting this summary here, and not above. It is from Makassar Terkini, translated into English - and is a great story covering the main aspects of this quake.

    MAKASSAR-6.1 earthquake on the Richter scale (SR) rocked Poso, Central Sulawesi, at 21:33 pm, earlier malam.Pada the same time, for 1.5 hours of power outages throughout the region South.

    Based on data Climatology Meteorology and Geophysics Agency (BMKG), the epicenter was in 143 kilometers southeast of Poso, Central Sulawesi and 155 kilometers northeast Palopo-South. Tremors felt in most of the Luwu Kingdom, South Sulawesi (Sulawesi) and even up to Barat.Paling Sulawesi residents strongly felt Soroako, East Luwu (Lutim). Shock that was felt until a few seconds it makes the people who settled around the area of PT International Nickel Indonesia (Inco) to panic and flee. Media Relations PT Inco Iskandar Siregar confirmed the tremor felt in Sorowako that make people run out rumah.Menurut him, felt the quake region Sorowako about five seconds.

    In Sub Nuha, Lutim, hundreds of people jump out of the earthquake is felt. In fact, one resident said her home cracked due to shocks. "Everyone scrambled out of the house and fled in panic. Due to strong goncangannya once, even cracked the walls of my house by the earthquake, the goods tumbled by a fall and cracked, "said one elementary school teacher yps Sorowako Ceriati Happy Rannu who contacted SINDO, last night. He tells us, a few ornaments and decorations mounted on the wall of his house collapsing due guncanagan hard. Residents around were scattered out looking for open space to avoid the possibility of a bigger quake.

    Panic residents compounded by power outages in the district when the earthquake struck. Despite the high shock is felt only about 1-2 minutes. "Everyone ran out and gathered, in the streets and on the Ground Ball Porsesos full of people who gathered, we are afraid not to get a bigger quake and nothing happened," he said. Based on data from official site BMKG, the quake occurred at a depth of 21 km to the south latitude location 2:45 (LS) - 121.49 East Longitude (BT). Of note BMKG, earthquake location is also close to Kendall that is located about 207 km west of Kendari, Southeast Sulawesi Sea, 247 km Northeast Sengkang, South Sulawesi.

    To 24.00 pm last night, aftershocks still felt the residents. Although the shocks are small. Residents are also still in the field in the District of Nuha Lutim. "People are still on the ground, shaking occasionally come but it was not as hard as the first time," said Ceriati who was contacted at 24.00 pm last night. The same thing also reported a citizen Sorowako, Indahyana Lia. He preached, preach if residents living around the main Sorowako area of PT Inco in the region gathered in the field or other open space to avoid the occurrence of aftershocks. Meanwhile, almost simultaneously with the earthquake, electricity in most areas off South Sulawesi.

    Law and Communications Assistant Manager of PT PLN Sultanbatara, M Yamin Loleh say, the occurrence of power outages in the area of South Sulawesi, Makassar and surroundings mainly by its internal network transmission interference between Tallo, Makassar-Pangkep. "The cause of the damage still be traced, but the damage to the transmission network of Tallo Pangkep until recently thought to be the cause utama.Tapi services will still be maximized," he explained when contacted SINDO. However, damage to underground transmission lines PLN can not clear whether affected by the 6.4 magnitude earthquake in Central Sulawesi Poso (Central Sulawesi). PLN itself according to Yamin, still continues to do an intensive examination.

    Electricity in the region had lost Sulselbar around 20.30 pm. Power outages caused by the interruption of transmission due to a lightning strike. "There was an interruption of transmission in Pangkep caused by lightning which resulted in breakdown of tissue from Pare-pare to Makassar," said General Manager of PLN Region Sulselbartra Ahmad Siang, the SINDO, last night. According to Ahmad, the condition causes the power supply to all regions terputus.Namun, he said it had prepared to handle these scenarios. The main priorities is to provide immediate supply to Makassar. "The whole power of approximately 530 Mega Watt (MW) of Makassar requires 260-275 megawatts, and it became our priorities for the capital of the province," he explained.

    He said the disruption could have been terjadi.Namun, the PLN has prepared a variety of anticipation for it. Although he takes some time for the region. "Events like that always, because it occurs suddenly due to the alam.Namun, we have set up anticipation for the flow of uninterrupted power for too long," he said. As a result of electrical padamnya about 1.5 hours, the number of red lights at some intersection point in Makassar is not working. As a result, a number of roads jammed protocol. As Jalan Sultan Alauddin, Jalan Talasalapang, Sultan Hasanuddin, Jalan AP Pettarani, Cockatoo Road, and Road Urip Sumohardjo. A number of areas that experienced outages, such as Bone, Wajo, Parepare, Maros, Pangkep, Barru, Palopo, and others.

    Evacuate (Fake SMS scandal - causing people to flee in fear of tsunami)

    Not only out of the house and filled the streets and fields, thousands of villagers from three subdistricts in Lutim, last night, chose to flee to the height of the earthquake to hit the area hard. Residents fled in panic to hear issues Sorowako and surrounding areas will be hit by the tsunami from the overflow of Lake Matano. Information obtained in Sorowako SINDO, displaced residents of three districts, namely citizens of District Nuha, Towuti, and Wowondula.

    In fact, villagers in the district Timampu Towuti, leaving their villages to flee to the hills in the District Wowondula. Especially in Sorowako, some residents fled to the hills around the airport (Airport) belongs to PT Inco.Mereka flee and panic get out of the house when he heard the issue will occur tsunami from Lake Matano, shortly after the earthquake, approximately at 21:30 pm , last night. Until 23:30 pm, residents were still displaced at the height of the area, though police officers from the police station and Kodim 1403 Lutim Sawerigading urged residents not to panic because the issue of tsunami after the earthquake.

    "People panicked and fled after hearing the tsunami issue of Lake Matano. This issue spread so quickly after the earthquake felt in Sorowako guncangannya and surrounding areas, "said police chief Firman Andi Lutim Sorowako, last night. Police claimed was in line with local government Sorowako Lutim and Kodim 1403 Sawerigading to calm the people not to panic, because the tsunami issue. "People panicked because it could see the water of the lake Matano moved quickly during the earthquake, so they chose to flee to the altitude, especially in hilly areas around the airport owned by PT Inco," said police chief. He said it is using megaphones to announce to the public that the quake that was felt in areas hard guncangannya Sorowako no tsunami potential.

    "We announce to the people calm and not panic, because we receive information from BMG that earthquake did not cause tsunami, let alone the tsunami from Lake Matano," explained police chief. Nuha Camat Andi Kasman confirmed separately, admitted the camps in three districts in the northern region Lutim, because the issue of tsunami after the earthquake. Not only Sorowako citizens, residents of one village Timampu, District Towuti, Kasman said, leaving their villages and fled to the mountains in the District Wowondula. Residents Wowondula also displaced by the tsunami panic hear the issue.

    In Lutim, loud enough tremor was felt in four districts, namely Nuha, Towuti, Wowondula, including Malili. "We are worried about family in Sorowako, because they were displaced by the tsunami issue," said Erwin Sanagih, one activist environmentalists in Malili, night earlier. Tremor was also felt in the City of Palopo. However, tremor was not too loud and lasted only about seven minutes. "Tremors felt the quake, but quick and not hard," said Deputy Mayor Grace Palopo Bandaso Masri. In Poso, First Brigadier Nusirwan, member of the Poso police station, told me, tremor took place around seven minutes.

    "About two minutes long the shaking was strong enough," said Nursirwan the time of the incident in the city of Poso, precisely near Poso police station. When the quake occurred, residents in Poso who panicked and ran out of the house. Katakutan residents were shocked by the earthquake, power outages. Until around 24.00 pm, most residents had returned to their homes. Information from the police, there were no reports of damage to houses and casualties caused by the earthquake. (Si-chaerul Baderu/Jumardin Akas/ Yakin Achmad/Andi Amriani/ Rahmat Ardiansya from Mamassar press with the story.....)

  2. I am @ soroako now. We had felt some series of shakes last night started from around 21.30 local time. Until now (16 Feb, 12:07 PM) , several shakes still happening. Rumour says some building were damaged and nickel mining activities were interrupted. Last night earthquakes made thousand of people flew out of home and stayed outside until around 3 AM.

    • Hi Padli,
      Thankyou so much for your input. I hope that life returns to normal soon.
      Yes, there are reports of slight damage and interruptions in the Soroako area but luckily it looks to have been quite low impact compared with other earthquakes of similar magnitude and distance.
      Thanks again, and we really appreciate getting reports from the most affected area.

  3. Paul Nikkel says

    Was in Sorowako during the quake - no damages aside from power outage and no injuries as far as I am aware.

    • Armand Vervaeck says

      Thank you so much Paul. Finally a signal out of Sorowako. You are enabling us to finalize the article with a very good feeling.
      Earthquakes can be very unpredictable. Was it a strong shaking and how long did it last approx. . Armand

  4. According to USGS, about 1,000 people felt this earthquake as severe shaking (VIII MCS intensity)