This list of earthquakes in Ecuador is a list of notable earthquakes that have affected Ecuador in recorded history.

Tectonic setting

The active tectonics of Ecuador is dominated by the effects of the subduction of the Nazca Plate beneath the South American Plate. Ecuador lies within the Northern Volcanic Zone where the subduction zone is moving at a rate of 7 cm/yr to the east-northeast, significantly oblique to the trend of this segment of the Andes. The subduction zone has an overall dip of 25–30°, but varies rapidly along strike due to the effects of subduction of the Carnegie Ridge. The Carnegie Ridge is an oceanic plateau that formed as the Nazca Plate passed over the Galapagos hotspot. The plate interface above the subducted part of the ridge has a shallower dip than the area to both north and south, the boundaries interpreted to consist of two large tears in the downgoing Nazca Plate.[1] The northern part of Ecuador overlies the subducted part of the Carnegie Ridge and is an area where the Nazca Plate is interpreted to be strongly coupled to the South American Plate, causing an unusually large degree of intraplate deformation. The main active fault zones of Ecuador are SSW-NNE trending dextral strike-slip faults running parallel to the main subdivisions of the Andes, two major SW-NE dextral strike-slip zones, the Pallatanga and Chingual faults, and north-south trending reverse faults such as the Quito fault.[2]

Seismicity

Earthquakes that affect Ecuador can be divided into those that result from movement on the subduction interface along the plate boundary, those that result from deformation within the South American and Nazca Plates and those that are associated with active volcanoes.

Interplate earthquakes

Megathrust events along the subduction interface generate the largest earthquakes, often triggering destructive tsunamis, such as the 1906 Ecuador–Colombia earthquake.

Intraplate earthquakes

The most damaging earthquakes to affect Ecuador are those associated with faulting within the South American Plate, such as the 1949 Ambato earthquake.

Earthquakes within the downgoing Nazca Plate, such as the Mw 7.1 event of August 2010, are generally too deep to cause significant damage in Ecuador although they are felt over a wide area.[3]

Volcanic earthquakes

Swarms of relatively small earthquakes are commonly associated with volcanic activity, such as the Quito swarm in 1998-1999 related to the Guagua Pichincha volcano.[4]

List of notable earthquakes

Date Time Event Location MMI Coord Deaths Mag. Notes Sources
1698-06-20 01:00 1698 Ambato earthquake Carihuairazo X 1°42′S 78°42′W / 1.7°S 78.7°W / -1.7; -78.7 6,500+ 7.2–7.9 Muk 
1797-02-04 12:30 1797 Riobamba earthquake Riobamba XI 1°36′S 78°36′W / 1.6°S 78.6°W / -1.6; -78.6 6,000-40,000 8.3 ML [5]
1868-08-16 06:30 1868 Ecuador earthquakes Ibarra 0°19′N 78°11′W / 0.31°N 78.18°W / 0.31; -78.18 70,000 6.7 Mw [6]
1906-01-31 15:36 1906 Ecuador–Colombia earthquake Esmeraldas IX 1°00′N 81°30′W / 1.0°N 81.5°W / 1.0; -81.5 1,000 8.8 Mw Tsunami [7]
1942-05-14 21:13 1942 Ecuador earthquake Pedernales IX 0°06′S 79°54′W / 0.1°S 79.9°W / -0.1; -79.9 200 7.8 ML [8]
1949-08-05 19:08 1949 Ambato earthquake Ambato XI 1°30′S 78°12′W / 1.5°S 78.2°W / -1.5; -78.2 5,050 6.8 ML [9]
1953-12-12 17:31 1953 Tumbes earthquake Guayaquil VIII 3°24′S 80°36′W / 3.4°S 80.6°W / -3.4; -80.6 7 7.5 Mw
1958-01-19 09:09 1958 Ecuador–Colombia earthquake Esmeraldas VII 1°30′N 79°30′W / 1.5°N 79.5°W / 1.5; -79.5 111 7.6 Mw [10]
1970-12-10 04:31 1970 Peru–Ecuador earthquake El Oro IX 3°59′S 80°43′W / 3.99°S 80.72°W / -3.99; -80.72 50 7.1 Mw
1976-04-09 07:08 1976 Esmeraldas earthquake Esmeraldas VIII 0°46′55″N 79°48′14″W / 0.782°N 79.804°W / 0.782; -79.804 10 6.7 Mw [11]
1979-12-12 02:59 1979 Tumaco earthquake Tumaco IX 1°35′53″N 79°21′29″W / 1.598°N 79.358°W / 1.598; -79.358 300–600 8.2 Mw Tsunami
1987-03-06 01:54 & 04:10 1987 Ecuador earthquakes Napo IX 0°04′N 77°45′W / 0.07°N 77.75°W / 0.07; -77.75 5,000 7.1 Mw [12]
1998-08-04 13:59 1998 Bahía de Caráquez earthquake Bahía de Caráquez, Manabí VIII 0°35′35″S 80°23′35″W / 0.593°S 80.393°W / -0.593; -80.393 3 7.2 Mw [13]
2010-08-12 11:54 2010 Riobamba earthquake Riobamba VI 1°15′36″S 77°18′43″W / 1.260°S 77.312°W / -1.260; -77.312 0 7.1 Mw Minor damage [3][14]
2014-08-12 19:58 2014 Ecuador earthquake Pichincha VI 0°01′N 78°19′W / 0.02°N 78.32°W / 0.02; -78.32 4 5.1 Mw [15]
2016-04-16 18:58 2016 Ecuador earthquake Pedernales, Manabí VIII 0°22′16″N 79°56′24″W / 0.371°N 79.940°W / 0.371; -79.940 676 7.8 Mw Severe damage [16][17]
2019-02-22 10:17 2019 Pastaza earthquake Pastaza VII 2°11′10″S 77°03′04″W / 2.186°S 77.051°W / -2.186; -77.051 1 7.5 Mw [18]
2022-03-26 23:28 2022 Esmeraldas earthquake Esmeraldas VI 0°54′32″N 79°35′20″W / 0.909°N 79.589°W / 0.909; -79.589 1 5.8 Mw  Severe damage [19][20]
2022-07-14 22:30 2022 Guayaquil earthquake Guayas V 2°02′24″S 79°48′40″W / 2.040°S 79.811°W / -2.040; -79.811 1 5.7 Mw  Minor damage [21]
2023-03-18 17:12 2023 Guayas earthquake Guayas VII 2°51′04″S 79°48′00″W / 2.851°S 79.800°W / -2.851; -79.800 18 6.8 Mw  Major damage [22]

Magnitudes - Mw Moment magnitude scale, ML Richter magnitude scale, Ms Surface wave magnitude

See also

References

  1. ^ Gutscher, M.-A.; Malavieille, J.; Lallemand, S.; Collot, J.-Y. (1999). "Tectonic segmentation of the North Andean margin: impact of the Carnegie Ridge collision" (PDF). Earth and Planetary Science Letters. 168 (3–4): 255–270. Bibcode:1999E&PSL.168..255G. doi:10.1016/S0012-821X(99)00060-6. Retrieved 24 August 2010.
  2. ^ Eguez, A.; Alvarado A.; Yepes H.; Machette M.N.; Costa C.; Dart R.L. "Database and Map of Quaternary faults and folds of Ecuador and its offshore regions" (PDF). USGS Open-File Report 03-289. pp. 2–3. Retrieved 22 August 2010.
  3. ^ a b USGS (20 August 2010). "Magnitude 7.1 - ECUADOR 12 August 2010 11:54:16 UTC". Retrieved 24 August 2010.
  4. ^ Legrand, D.; Villagómez D.; Yepes H.; Calahorrano A. (2004). "Multifractal dimension and b value analysis of the 1998–1999 Quito swarm related to Guagua Pichincha volcano activity, Ecuador". Journal of Geophysical Research. 109 (B01307). Bibcode:2004JGRB..10901307L. doi:10.1029/2003JB002572. Retrieved 24 August 2010.
  5. ^ NGDC. "Comments for the Significant Earthquake". Retrieved 20 August 2010.
  6. ^ Giesecke, A.; Capera A.A.G.; Leschiutta I.; Migliorini E.; Valverde L.R. (2004). "The CERESIS earthquake catalogue and database of the Andean Region: background, characteristics and examples of use" (PDF). Annals of Geophysics. 47 (2/3): 421–435. Retrieved 22 August 2010.
  7. ^ Mendoza, C.; Dewey J.W. (1984). "Seismicity associated with the great Colombia-Ecuador earthquakes of 1942, 1958, and 1979: Implications for barrier models of earthquake rupture". Bulletin of the Seismological Society of America. 74 (2): 577–593. Retrieved 2010-03-07.
  8. ^ "M7.8 - Ecuador".
  9. ^ NGDC. "Comments for the Significant Earthquake". Retrieved 22 August 2010.
  10. ^ Paula Dunbar. "Significant Earthquake".
  11. ^ "M 6.7 - near the coast of Ecuador". United States Geological Survey. Retrieved 2019-11-25.
  12. ^ "Officials Fear Quake Killed 300 in Ecuador". Los Angeles Times. Reuters. 1987-03-10. Retrieved 18 April 2016.
  13. ^ NGDC. "Comments for the Significant Earthquake". Retrieved 22 February 2011.
  14. ^ USGS (20 August 2010). "2010 August 12 11:54:16 UTC Earthquake Details". Retrieved 22 August 2010.
  15. ^ "M 5.1 - 22km WSW of Cayambe, Ecuador". United States Geological Survey. Retrieved 2019-11-20.
  16. ^ USGS (16 April 2016). "M7.8 - 27km SSE of Muisne, Ecuador". Retrieved 16 April 2016.
  17. ^ "Rescue goes slowly in Ecuador after 7.8 quake; death toll tops 400, expected to rise further". Los Angeles Times. 18 April 2016. Retrieved 18 April 2016.
  18. ^ EQ Report (22 February 2019). "Dangerous massive earthquake below the Ecuadorian Selva (Peru border region) - February 22, 2019". Archived from the original on 22 February 2019. Retrieved 22 February 2019.
  19. ^ "M 5.8 - 9 km SE of Esmeraldas, Ecuador". earthquake.usgs.gov. U.S. Geological Survey. 27 March 2022. Retrieved 27 March 2022.
  20. ^ "Sismo en Ecuador: al menos un muerto, fuertes réplicas y viviendas dañadas tras temblor de magnitud 6". Agence France-Presse (in Spanish). El Comercio. 27 March 2022. Retrieved 27 March 2022.
  21. ^ "M 5.7 - 12 km SW of Samborondón, Ecuador". earthquake.usgs.gov. 14 July 2022. Retrieved 15 July 2022.
  22. ^ National Earthquake Information Center (18 March 2023). "M 6.8 – 10 km NNW of Baláo, Ecuador". United States Geological Survey. Retrieved 18 March 2023.
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