1995 Neftegorsk earthquake

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1995 Neftegorsk earthquake
1995 Neftegorsk earthquake is located in Far Eastern Federal District
1995 Neftegorsk earthquake
UTC time1995-05-27 13:03:53
ISC event106336
USGS-ANSSComCat
Local date27 May 1995 (1995-05-27)
Local time1:04 a.m. local time
MagnitudeMs (HRV)  7.1 [1]
Depth11.0 km (7 mi) [2]
Epicenter52°38′N 142°50′E / 52.63°N 142.83°E / 52.63; 142.83Coordinates: 52°38′N 142°50′E / 52.63°N 142.83°E / 52.63; 142.83
TypeStrike-slip [3]
Areas affectedSakhalin, Russian Far East
Total damage$64.1–300 million [3]
Max. intensityIX (Violent)[4]
Casualties1,989 dead [3]
750 injured [3]

The 1995 Neftegorsk earthquake occurred on 28 May at 1:04 local time[5] on northern Sakhalin Island in the Russian Far East.[6] It was the most destructive earthquake known within the current territory of Russia,[7] with a magnitude of Ms  7.1 and maximum Mercalli intensity of IX (Violent)[8] that devastated the oil town of Neftegorsk, where 2,040 of its 3,977 citizens were killed, and another 750 injured.[9]

90% of the victims were killed by the collapse of 17 five-story residential buildings.[10] While Western media generally attributed the collapses to allegedly poor construction and shoddy materials of Soviet-era construction,[11] a geotechnical study faulted a failure to accommodate the possibility of soil liquefaction in an area that was considered "practically aseismic".[12]

The Belgian Centre for Research on the Epidemiology of Disasters' EM-DAT database places the total damage at $64.1 million, while the United States' National Geophysical Data Center assesses the damage at $300 million.[3]

1995 Neftegorsk earthquake monument in Yuzhno-Sakhalinsk

This quake was not only catastrophic, it was totally unexpected: earthquakes with magnitudes greater than 6 were not known to occur in the area of northern Sakhalin Island.[13] It is also of great scientific interest (some 20 papers have been published[14]) because it occurred near a poorly known tectonic plate boundary where the Okhotsk Plate (connected with North American Plate) is crashing into the Amurian Plate (part of the Eurasian Plate),[15] and indicates that the plate boundary is associated with a north-south striking seismic belt that runs the length of Sakhalin. More precisely, this earthquake occurred on the Upper Piltoun fault (also known as the Gyrgylan'i—Ossoy fault[16]), which branches off the main Sakhalin-Hokkaido fault that runs along the east side of the island.[17]

35 km (22 mi) of surface rupturing was observed (46 km including a branching fault), with an estimated average lateral displacement of about 4 meters, but up to 8 m (9 yd) in some places.[18] (This compares to 14 km of slip estimated to have accumulated on the Sakhalin-Hokkaido fault in the last 4 million years.[19]) The unusual strength of this quake and length of rupturing, and the low level of seismic activity before hand, has been attributed to the accumulation of strain over a long period of time on a locked fault segment.[20]

See also[edit]

Notes[edit]

  1. ^ ISC-EB Event 106336 [IRIS] ANSS reports this as Mwb  7.1.
  2. ^ ISC-EHB Event 106336 [IRIS].
  3. ^ a b c d e USGS (September 4, 2009), PAGER-CAT Earthquake Catalog, Version 2008_06.1, United States Geological Survey
  4. ^ ISC-EHB Event 106336 [IRIS].
  5. ^ Klyachko 2001, p. 1.
  6. ^ ANSS: Sakhalin 1995.
  7. ^ Arefiev et al. 2000, p. 595.
  8. ^ ISC-EHB Event 106336 [IRIS]. The ANSS: Sakhalin 1995 reviewed value on the Mwb scale is also 7.1. Some sources have reported the magnitude as Ms   7.6.
  9. ^ Earth Chronicles (2016) attributes the fatality numbers to the Russian Ministry of Emergencies. The ISC, without citing a source, says "[a]s many as 1,989 people killed" (ISC-EHB Event 106336 [IRIS]). Other sources attribute the "more than 2000" number to Japanese language sources.
  10. ^ Klyachko 2001, p. 1. These buildings housed all but about 650 of the town's residents. Los Angeles Times 1995
  11. ^ Los Angeles Times 1995.
  12. ^ Klyachko 2001, p. 2.
  13. ^ Arefiev et al. 2000, pp. 595, 605.
  14. ^ ISC-EB Event 106336 [IRIS].
  15. ^ Arefiev et al. 2000, p. 595; Katsumata et al. 2004, pp. 117, 129.
  16. ^ Katsumata et al. 2004, p. 117
  17. ^ Arefiev et al. 2000, p. 596.
  18. ^ Arefiev et al. 2000, p. 599.
  19. ^ Arefiev et al. 2000, p. 596.
  20. ^ Arefiev et al. 2000, p. 606.

Sources[edit]

  • Johnson, M. S. (1998), "The Tale of the Tragedy of Neftegorsk", Prehospital and Disaster Medicine, 13 (1): 67–72, PMID 10187029.

External links[edit]