1981 Golbaf earthquake
  Tehran Kerman  | |
| UTC time | 1981-06-11 07:24:25 |
|---|---|
| ISC event | 625020 |
| USGS-ANSS | ComCat |
| Local date | June 11, 1981 |
| Local time | 10:54:25 IRST |
| Magnitude | 6.6 Mw[1] 6.7 Ms[2] |
| Depth | 18 km (11 mi)[1] |
| Epicenter | 29°55′N 57°50′E / 29.91°N 57.83°E[1] |
| Type | Strike-slip and reverse[3] |
| Total damage | $5 million[4] |
| Max. intensity | MMI VIII (Severe)[5] |
| Foreshocks | No[3] |
| Aftershocks | 1981 Sirch earthquake |
| Casualties | 3,000 injured 1,400 killed[5] |
The 1981 Golbaf earthquake struck the Iranian desert by the village of Golbaf on June 11 at 10:54:25 local time. The shock measured 6.6 on the moment magnitude scale, and had a surface-wave magnitude of 6.7. The shock had a maximum Mercalli intensity of VIII (Severe). Many villages were devastated and financial losses amounted to $5 million (in 1981 USD). Despite the sparsity of the area, 3,000 were injured and 1,400 were killed.
Tectonic Setting
[edit]Eastern Iran is moving at a rate of approximately 15 mm (0.59 in)/yr with respect to Afghanistan. To acommodate this, the 600 km (370 mi) north-south trending Sabzevaran-Gowk-Nayband fault system began to develop in the western margin of the Dasht-e Lut.[6][7]
The Gowk fault is a north-northwest trending fault that extends for over 150–180 km (93–112 mi) across the Lut Desert in Kerman Province, Iran.[3][8] The fault moves dextrally and reverse, and has slipped at a rate of around 3.1–5.7 mm (0.12–0.22 in)/yr for the past 6-8 kyr.[i][3][9][10] With a strike of 155 degrees, the Gowk fault does not orient itself parallel with the slip in the region. As a result, the Shahdad Thrust system takes up the shortening component of regional slip.[11] The Gowk fault is very active, generating multiple other destructive earthquakes such as the 1981 Sirch earthquake.[6] Despite this activity, a ~90–100 km (56–62 mi) segment in the south of the fault (Sarvestan segment) has remain unbroken, leading to a high potential hazard for future earthquakes.[6][9]
Earthquake
[edit]The Mw6.6, Ms6.7 shock struck near the village of Golbaf at 10:54:25 local time.[1][2] The earthquake had a maximum Modified Mercalli intensity of VIII (Severe).[5] The complex rupture extended across at least 15 km (9.3 mi) of the Gowk fault system.[12] An eastern segment slipped 3 cm (1.2 in) dextrally and 5 cm (2.0 in) vertically over a 14.5 km (9.0 mi) span. A western segment had little offset over a 7.5 km (4.7 mi) rupture, but fissured along its length.[3] These surficial displacements are far smaller than would be expected for an earthquake of this size, but this can be explained by the depth of the earthquake.[13] Average slip at depth was estimated to be 1.4 m (4 ft 7 in).[14] The earthquake led to a static stress increase of 3.4 bar on the southern Sarvestan segment of the Gowk fault.[15] Additionally, an increase of up to 2 bars to the north helped trigger the later 1981 Sirch earthquake.[16]
Aftershocks
[edit]The earthquake had a few mb4+ aftershocks for the next couple weeks, but seismicity was not well recorded by teleseismic observations.[17] A month and a half after the mainshock, on July 28, the 1981 Sirch earthquake struck along the Gowk fault in a similar area. Despite nucleating in the same area, it ruptured in a completely different direction, with the rupture zones having no overlap.[18] It caused further destruction to the already severely damaged villages nearby, though killed much fewer people as the populace was living in tents after the original shock.[19]
Impact
[edit]The strong earthquake left 3,000 injured and 1,400 killed.[5] Every village in the Golbaf depression was devastated.[3] Losses were estimated at $5 million USD (in 1981 dollars).[4]
See also
[edit]Notes
[edit]- ^ kyr = thousand years
References
[edit]- ^ a b c d International Seismological Centre. Bulletin of the ISC. Thatcham, United Kingdom. [Event 625020].
- ^ a b "M 6.7 - 73 km SE of Kerman, Iran". United States Geological Survey. Retrieved 26 June 2025.
- ^ a b c d e f Berberian et al. 1984, p. 814.
- ^ a b National Geophysical Data Center / World Data Service (NGDC/WDS) (1972). "Significant Earthquake Database" (Data Set). National Geophysical Data Center, NOAA. doi:10.7289/V5TD9V7K. Archived from the original on September 29, 2006.
- ^ a b c d Berberian 2014, p. 611.
- ^ a b c Fattahi et al. 2014, p. 334.
- ^ Walker & Jackson 2002, p. 1679.
- ^ Walker et al. 2010, p. 222.
- ^ a b Walker et al. 2010, p. 221.
- ^ Fattahi et al. 2014, p. 335.
- ^ Walker & Jackson 2002, p. 1679-1680.
- ^ Berberian et al. 1984, p. 809.
- ^ Berberian et al. 2001, p. 389.
- ^ Nalbant, Steacy & McCloskey 2006, p. 311.
- ^ Nalbant, Steacy & McCloskey 2006, p. 312.
- ^ Nalbant, Steacy & McCloskey 2006, p. 316.
- ^ Berberian et al. 1984, p. 821.
- ^ Berberian et al. 1984, p. 835.
- ^ Berberian et al. 1984, p. 816-817.
Sources
- Berberian, M. (2014). Earthquakes and Coseismic Surface Faulting on the Iranian Plateau. Developments in Earth Surface Processes (1st ed.). Elsevier. p. 1-714. ISBN 978-0444632920.
- Berberian, M.; Jackson, J. A.; Fielding, E.; Parsons, B. E.; Priestley, K.; Qorashi, M.; Talebian, M.; Walker, R.; Wright, T. J.; Baker, C. (2 August 2001). "The 1998 March 14 Fandoqa earthquake (Mw 6.6) in Kerman province, southeast Iran: re-rupture of the 1981 Sirch earthquake fault, triggering of slip on adjacent thrusts and the active tectonics of the Gowk fault zone". Geophysical Journal International. 146 (2): 371–398. doi:10.1046/j.1365-246x.2001.01459.x. Retrieved 27 June 2025.
- Berberian, M.; Jackson, J. A.; Ghorashi, M.; Kadjar, M. H. (3 June 1984). "Field and teleseismic observations of the 1981 Golbaf-Sirch earthquakes in SE Iran". Geophysical Journal International. 77 (3): 809–839. doi:10.1111/j.1365-246X.1984.tb02223.x. Retrieved 27 June 2025.
- Fattahi, M.; Walker, R. T.; Talebian, M.; Sloan, R. A.; Rasheedi, A. (1 January 2014). "Late Quaternary active faulting and landscape evolution in relation to the Gowk Fault in the South Golbaf Basin, S.E. Iran". Geomorphology. 204: 334–343. doi:10.1016/j.geomorph.2013.08.017. ISSN 0169-555X. Retrieved 27 June 2025.
- Nalbant, Suleyman S.; Steacy, Sandy; McCloskey, John (1 October 2006). "Stress transfer relations among the earthquakes that occurred in Kerman province, southern Iran since 1981". Geophysical Journal International. 167 (1): 309–318. doi:10.1111/j.1365-246X.2006.03119.x. Retrieved 27 June 2025.
- Walker, Richard; Jackson, James (1 November 2002). "Offset and evolution of the Gowk fault, S.E. Iran: a major intra-continental strike-slip system". Journal of Structural Geology. 24 (11): 1677–1698. doi:10.1016/S0191-8141(01)00170-5. Retrieved 27 June 2025.
- Walker, R. T.; Talebian, M.; Sloan, R. A.; Rasheedi, A.; Fattahi, M.; Bryant, C. (April 2010). "Holocene slip-rate on the Gowk strike-slip fault and implications for the distribution of tectonic strain in eastern Iran". Geophysical Journal International. 181 (1): 221–228. doi:10.1111/j.1365-246X.2010.04538.x. Retrieved 27 June 2025.
External links
[edit]- The International Seismological Centre has a bibliography and/or authoritative data for this event.