Information messageabout the earthquake on November 12, 1999 in Turkey |
| On November 12, 1999 at 19:57 Moscow time (16:57 GMT) the catastrophic earthquake has happened in Turkey. Hypocenter of this event was located in 110 km to the east from hypocenter of destructive earthquake, which occurred on August 17, 1999 with magnitude M=7.6 and killed 17 thousand lives. The nearest living place is Adapazari (Sakarya) having population 186 thousand people and situated 60 km to the east from this event's hypocenter. |
| Parameters of the earthquake have been determined by Alert Service (AS) of the Information Processing Center (IPC) in Geophysical Survey of RAS in Obninsk with use of station data obtained from digital and analog stations of Russia, countries of CIS and from abroad. Preliminary summary processing was conducted after getting data from 17 stations located to the north and north-east from the hypocenter. Additional information from foreign stations, located to the south and south-west from hypocenter (Spain, Greece and South African Republic), which was obtained via Internet from European information server ORFEUS gave the opportunity to improve detection of hypocenter's location and get more accurate parameters of this earthquake. |
| Pictures 2-3 contain records from digital stations obtained by IPC in a close to real time mode.
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Figure 1
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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 |
16-57-19.40 |
40 |
31 |
20 |
30 |
7.20/13 | 6.90/3 | 9-9.5 | | IPC GS RAS (improved) | | 2 |
16-57-22.0 |
41 |
31 |
20 |
17 |
7.1/4 | 6.9/3 | 9-9.5 | | IPC GS RAS (preliminary) | | 3 |
16-57-20.31 |
40 |
31 |
10 |
96 |
/3 | 6.5/57 | | | NEIC (improved) | | 4 |
16-57-19.20 |
40 |
31 |
|
16 |
/1 | 5.7/12 | | | pIDC (preliminary) | | 5 |
16-57-20.8 |
40 |
31 |
25 |
|
| | | | KOERI | |
| IPC GS RAS - Informational Processing Center, Geophysical Survey, Russian Academy of Sciences |
| NEIC - National Earthquakes Information Center of US Geological Service |
| pIDC - Prototype International Data Center |
| KOERI - Kandilli Observatory and Earthquake Research Institute, Turkey |
| Epicenter |
| Location of hypocenter according to improved data of AS is shown on picture 3.
|
Figure 3 |
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| Macroseismic manifestations |
| Hypocenter of this event has been located 100 km to the east from the main strike place of the destructive earthquake on August 17, 1999. From NEIC data the nearest big town is Adapazari (Sakarya) with population 186 thousand people, which is 60 km east to the hypocenter.
This earthquake was felt in towns of Moldova and Ukraine: in Kishinev, Simferopol and all around Black Sea coast of Crimea with intensity of 2-3 MSK.
|
| Historical records |
| Was given in Information message about catastrophic event on August 17, 1999. |
| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism of the earthquake 12.11.1999 was calculated in IPC GS RAS after getting the first signs of Р-wave arrivals at 61 stations, which are located in interval of hypocenter's distances between 6-99 degrees with enough uniform distribution among azimuths from 12 to 359 degrees. Positions of nodal planes in projection of lower hemisphere are shown on picture 4 and in table 3.
Here one can find the solution obtained in Harvard center (USA) by method of centroid's moment tensor (CMT). All solutions are close to each other. Focal mechanism practically presents shift along the both nodal planes. Both planes have deep depth, one of them is oriented almost along meridian direction, while the other along latitude. Axis of compression and expand are nearly horizontal.
Seismic moment Mo of the earthquake was detected by spectrum of P-wave, registered on seismic station Talaya (TLY), located at the distance of 49 degrees from the hypocenter. The value of seismic moment made Mo= 9.1 E 19 n* m while the value of moment's magnitude Mw=7.3. From data in Harvard center these values made Mo=6.5 E 19 n* m and Mw=7.1.
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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 |
| 22 | 219 | 28 | 117 |
53 | 342 | 260 | 53 | -175 | 167 |
86 | -37 | IPC GS RAS | | 3 | 216 | 33 | 124 |
57 | 311 | 265 | 65 | -158 | 166 |
70 | -27 | HARVARD | |
| IPC GS RAS - Informational Processing Center, Geophysical Survey, Russian Academy of Sciences |
| HARVARD - Harvard Geophysical Center (USA) |
Figure 4 |
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