Information message about the earthquake on June 4, 2000 in Indonesia, near Sumatera island |
On June 4, 2000 at 20:28 Moscow time (4:28pm GMT) the strong earthquake has happened in the region of Indonesian island Sumatera, in 110 km to the south-west from Bengkulu and in 540 km west-north-west from Jakarta. From ITAR-TASS agency message this earthquake was felt in Jakarta and Singapore. On June 5 not less than 40 people were killed. Whole living sites have been totally destroyed by the strike. |
Parameters of the earthquake
have been determined in the Alert Service (AS) of Information
Processing Center (IPC) of Geophysical Survey of RAS in Obninsk with station data
obtained from digital and analog seismic stations of Russia, countries of CIS
and from abroad. Alert message on this earthquake has been delivered in 1 ÷ 50 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
Preliminary processing has been done with data from 16 stations, accurate processing - with data 27 stations. |
Figures 1-2 present fragments of records, which were received by IPC from digital stations in a close to real time mode. |
 Figure 1 |  Figure 2 |
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IPC GS RAS also has obtained information with parameters of this event from some seismological centers, these data are given in table 1: |
Table 1 |
NN |
Time in origin h-min-s (GMT) |
Lat degr. |
Lon degr. |
Depth km |
N s/st |
Ms/ N |
mb/ N |
I0 calc |
GAP |
Center | 1 |
16-28-23.10 |
5 |
102 |
33 |
16 |
7.70/12 | 7.20/9 | 9-9.5 | | IPC GS RAS (Initial) | 2 |
16-28-25.9 |
4 |
102 |
33 |
27 |
7.7/13 | | 9-9.5 | | IPC GS RAS (Improved) | 3 |
16-28-26.7 |
4 |
102 |
33 |
101 |
7.7-7.9 | 5.5-7.7 | | | CSEM | 4 |
16-28-25.6 |
4 |
102 |
33 |
43 |
7.9 | | | | NEIC | 5 |
16-28-24.6 |
4 |
102 |
10 |
19 |
| 6.2 | | | IDC | |
IPC GS RAS - Informational Processing Center, Geophysical Survey, Russian Academy of Sciences |
CSEM - European - Mediterranean seismological center |
NEIC - National Earthquakes Information Center of US Geological Service |
IDC - International Data Senter, Austriya, Viena |
Epicenter |
Location of hypocenter is shown on the map, which was issued by National Information Center of US Geological Service (USGS) and downloaded from WEB site of this organization. |
 Figure 3 |
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Aftershock |
In 11 minutes after this earthquake the other strong strike has happened with magnitude more than 7. These earthquakes were accompanied by numerous aftershocks (â„–â„– 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14). |
Macroseismic manifestations |
Hypocenter of this earthquake is located in the Indian Ocean in 110 km to the south-south-west from Bungkulu town, which is situated in the south of Sumatera island. According to messages of ITAR-TASS one hotel and two bank buildings have fallen in the town as a result of strikes. Big crack has appeared in the middle of one of the main highways. The salvors work on ruins in searches of victims. Local people construct temporary shelters and do not risk to return in the existing buildings. There is no traffic because of the broken roads and debris. Local airport is closed.
This earthquake was felt in Jakarta and Singapore. On June 5, 2000 not less than 40 people were killed. Correspondents of ITAR TASS say that in the zone of disaster the strike has fully destroyed some living places. Hospitals are full of injured people.
|
Historical records |
According to the seismological bulletin of CEME GS RAS the region of south Sumatera (3-6 degrees of south latitude and 100-104 degrees of east longitude) since 1955 and up now is known as the place of 11 earthquakes with magnitude 6.5 and more (see table 2). |
Таблица 2 |
Date yy/mm/dd | Time, in origin | Latitude, degr | Longitude, degr | Depth, km | MPSP | MS | 1959/11/26 | 23-09-23.0 | -5.50 | 103.50 | Â | Â | 6.5 | 1974/10/10 | 21-32-10.0 | -4.10 | 102.80 | Â | 6.6 | Â | 1975/10/01 | 03-29-59.0 | -4.80 | 102.20 | 33 | 7.0 | Â | 1975/10/01 | 04-13-28.0 | -4.90 | 102.10 | 45 | 6.8 | Â | 1977/11/18 | 10-17-43.0 | -4.10 | 101.90 | 40 | 6.5 | 6.0 | 1978/06/24 | 09-31-38.0 | -4.88 | 102.32 | 33 | 6.5 | 6.3 | 1979/01/11 | 06-28-14.3 | -4.05 | 101.31 | 40 | 6.5 | 6.3 | 1980/10/08 | 16-04-48.3 | -5.04 | 103.09 | 49 | 6.5 | 6.2 | 1985/12/27 | 05-38-56.6 | -5.55 | 103.94 | 44 | 6.6 | 6.5 | 1994/01/21 | 18-00-17.4 | -4.59 | 103.63 | 80 | 6.6 | 5.3 | 1995/11/05 | 16-30-02.6 | -4.77 | 103.31 | 67 | 7.2 | 6.0 |
As it is seen this earthquake is the strongest in the specified region for the last years. Its character can cause destructive waves of tsunami. Still there is no sufficient information on situation in the region of Sumatera and other islands. At the same time this is the second strong earthquake in Indonesia within the calendar month. The first destructive earthquake with magnitude M=7.2 has happened on May 4, 2000 in the region of Sulavesi island. Its hypocenter was located in the sea nearly 95 km to the south-east from regional center Luvuk located at the most eastern point of Sulavesi. This earthquake was accompanied with six meter waves of tsunami. According to information from ITAR TASS dozens of people living in this region with relatively small density of population were hit and injured, 50 of them were killed. Underground shocks and waves of tsunami destroyed or washed off in the sea hundreds of living buildings. One of relatively small islands with five villages "disappeared". Most of all were hit living sites and villages on the small islands – Bangai and Peleng. These sites felt double strikes from underground and sea waves.
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Focal mechanism and seismic moment of the earthquake |
Focal mechanism of the origin and seismic moment from table 3 were determined by Harvard Geophysical Laboratory (HRV solution) and National Information Center of US Geological Service (USGS Rapid Moment Tensor Solution). |
Таблица 3 |
|
HRV solution | USGS Rapid Moment Tensor Solution | Seismoware eq@seismology.harvard.edu quick CMT: 06/04/00, 16:28:25, SOUTHERN SUMATERA, INDONESIA, Mw=7.8
CENTROID, MOMENT TENSOR SOLUTION HARVARD EVENT-FILE NAME M060400A DATA USED: GSN MANTLE WAVES: 39S,109C, T=135 CENTROID LOCATION: ORIGIN TIME 16:28:35.9 0.3 LAT 4.99S 0.02;LON 101.73E 0.02 DEP 54.2 1.4;HALF-DURATION 23.5 MOMENT TENSOR; SCALE 10**27 D-CM MRR= 3.01 0.12; MTT=-2.86 0.07 MFF=-0.15 0.09; MRT=-3.46 0.17 MRF= 1.41 0.18; MTF=-5.37 0.06 PRINCIPAL AXES: 1.(T) VAL= 6.91;PLG=41;AZM=225 2.(N) 0.49; 46; 67 3.(P) -7.40; 11; 325 BEST DOUBLE COUPLE:M0=7.2*10**27 NP1:STRIKE= 14;DIP=53;SLIP= 25 NP2: 269; 71; 140

| Stuart Sipkin sipkin@usgs.gov 00/06/04 16:28:25.65 SOUTHERN SUMATERA, INDONESIA Epicenter: -4.734, 102.047 MW=7.7 MOMENT TENSOR SOLUTION Depth 5 No. of sta: 17 Moment Tensor; Scale 10**20 Nm Mrr= 2.97 Mtt=-1.94 Mff=-1.02 Mrt= 0.34 Mrf=-1.95 Mtf=-2.34 Principal axes: T Val= 4.04 Plg=61 Azm= 63 N -0.02 28 223 P -4.02 9 317
Best Double Couple:Mo=4.0*10**20 NP1:Strike= 76 Dip=44 Slip= 133 NP2: 205 59 57

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Average value of seismic moment Mo of this earthquake determined in IPC GS RAS by P-wave spectra from two seismic stations: Talaya (delta=56.6 degr.), Kislovodsk (delta=72.3 degr.) made 4.2*10**20 n*m (4.2*10**27 D-CM). Kanamori value of moment magnitude makes Mw=7.7.
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Table 2 |
Axes of main strengths |
Nodal planes |
Center |
T |
P |
N |
NP1 |
NP2 |
Pl |
Azm |
Pl |
Azm |
Pl |
Azm |
Stk |
Dp |
Slip |
Stk |
Dp |
Slip |
61 | 63 | 9 | 317 |
28 | 233 | 76 | 44 | 133 | 205 |
59 | 57 | NEIC | 41 | 225 | 11 | 325 |
46 | 67 | 14 | 53 | 25 | 269 |
71 | 140 | HARVARD | |
NEIC - National Earthquakes Information Center of US Geological Service |
HARVARD - Harvard Geophysical Center (USA) |
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