2009 Karonga earthquakes

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2009 Karonga earthquakes
2009 Karonga earthquakes is located in Malawi
2009 Karonga earthquakes
UTC time ??
ISC event
USGS-ANSS
Date * December 6–19, 2009
Local date
Local time
Magnitude Mw ~6.0
Casualties 4 deaths
Deprecated  See documentation.

The 2009 Karonga earthquakes occurred near Karonga, Malawi in December 2009 near the northern tip of Lake Malawi in southeast Africa.

List of shocks[edit]

Date Local Time
(UTC +2)
Magnitude
(Mw)
Latitude Longitude Depth Casualties
December 6, 2009 19:36 5.8 10.16°S 33.82°E 10 km[1]
December 8, 2009 05:08 5.9 9.948°S 33.878°E 8 km[2] 1[3]
December 12, 2009 04:27 5.4 9.96°S 33.88°E 10 km[4]
December 19, 2009 15:02 6.0 10.108°S 33.818°E 6 km 3[3]

Damage[edit]

Over 1000 houses collapsed, 4 people were killed and 300 people were wounded in this earthquake sequence.[5] The majority of the building collapse was caused by liquefaction that occurred within a shallow layer of saturated unconsolidated lake sediments along the shoreline.[6] The locations of ground damage and liquefaction align with the fault that ruptured the earthquake.[6]

Extent[edit]

The 6.0 earthquake could also be felt in Tanzania and Zambia.[7]

Geology[edit]

Being in the southern East African Rift, the 100 km-long Livingstone Fault marks the limit of the Karonga Basin. The earthquakes, located at about 50 km west of the Livingstone Fault, occurred along previously unknown buried faults beneath the Quaternary unconsolidated sediments. Satellite-based geophysical investigations indicated that one of the west dipping faults which cut the Karonga Basin might have ruptured during the earthquakes.[8][9] The studies also estimated a maximum slip of about 120 cm at 3–5 km depth with no evidence of dike-injection related activity associated with many earthquakes in Eastern Africa. [9] Another study utilized aeromagnetic data to image the basement structure around the rupture area and found that multiple buried faults ruptured during the earthquake among which are the St. Mary Fault (extending over 37 km in length) and the Kaporo Fault which is 36 km long and is buried beneath Lake Malawi.[10] Scientists have proposed that the dominance of seismicity in this part of northern Malawi may be due to the presence of pre-existing planes of weakness in the basement rocks that are favorably oriented to the tectonic stress field of the East African Rift.[10]

References[edit]

  1. ^ "M5.8 – Malawi". Earthquake.usgs.gov. Retrieved 2010-08-01. 
  2. ^ "M5.9 – Malawi". Earthquake.usgs.gov. Retrieved 2010-08-01. 
  3. ^ a b "Significant Earthquakes of the World". Earthquake.usgs.gov. Retrieved 2010-08-01. 
  4. ^ "M5.4 – Malawi". Earthquake.usgs.gov. Retrieved 2010-08-01. 
  5. ^ "COMET - Centre for the Observation and Modelling of Earthquakes and Tectonics | Homepage". Comet.nerc.ac.uk. Archived from the original on 13 August 2010. Retrieved 2010-08-01. 
  6. ^ a b Kolawole, F; Atekwana, E A; Laó-Dávila, D A; Abdelsalam, M G; Chindandali, P R; Salima, J; Kalindekafe, L (2018-02-19). "High-resolution electrical resistivity and aeromagnetic imaging reveal the causative fault of the 2009 Mw 6.0 Karonga, Malawi earthquake". Geophysical Journal International. 213 (2): 1412–1425. doi:10.1093/gji/ggy066. ISSN 0956-540X. 
  7. ^ "PAGER - M 6.0 - MALAWI". Earthquake.usgs.gov. Retrieved 2010-08-01. 
  8. ^ http://www.knmi.nl/~graafdem/publications/2010_ESA_LP_Dransfeld_etal.pdf
  9. ^ a b Hamiel, Y.; Baer, G.; Kalindekafe, L.; Dombola, K.; Chindandali, P. (October 2012). "Seismic and aseismic slip evolution and deformation associated with the 2009-2010 northern Malawi earthquake swarm, East African Rift". Geophysical Journal International. 191 (3): no–no. doi:10.1111/j.1365-246x.2012.05673.x. ISSN 0956-540X. 
  10. ^ a b Kolawole, F.; Atekwana, E. A.; Laó-Dávila, D. A.; Abdelsalam, M. G.; Chindandali, P. R.; Salima, J.; Kalindekafe, L. (March 2018). "Active Deformation of Malawi Rift's North Basin Hinge Zone Modulated by Reactivation of Preexisting Precambrian Shear Zone Fabric". Tectonics. 37 (3): 683–704. doi:10.1002/2017tc004628. ISSN 0278-7407. 

External links[edit]