Anatolian tectonic plate, north anatolian fault, historical earthquakes Greece, Attica, Earthquakes, Tsunami, , Hurricanes, Volcanic Eruptions and other Natural and Man-Made Hazards and Disasters - by Dr. George Pararas Carayannis


Tsunami, Earthquakes, Hurricanes, Volcanic Eruptions, Climate Change and other Natural and Man-Made Hazards and Disasters - Disaster Archaeology,



George Pararas-Carayannis


A large earthquake off the northern coastal region of Peru caused minor damage but generated a local destructive tsunami in the Chimbote region of Peru.


Epicenter -
9.6783 South Latitude, 79.798 West Longitude, near the Peru-Chile Trench, off the coast of Northen Peru.

Time of Origin - 12:51:04.4 GMT, February 21, 1996 (7:51 a.m., February 21, 1996, local time and date)

Magnitude - Mw 7.5

Focal Depth - Shallow.

Fault Plane - According to the Harvard University determination the earthquake source had the following parameters.
AZM PLG1. (P) 245 30,2. (T) 61 60 3. (N) 154 2

STRIKE DIP - NP1:340 15 , NP2:153 75

Aftershocks - Numerous aftershocks occurred from 120 to 180 Km off the coast of Peru near the Peru-Chile trench and appreared to be parallel to the Peruvian coastline.

Rupture Speed - The rupture velocity was classified as moderately slow (Newman and Okal, 1996).

Felt Reports - Most of the local residents reported that they did not feel the ground motions of the earthquake. Some reported only moderate shaking.

Death Toll and Damages - The earthquake caused very little damage. Most of the deaths and damages were caused by the tsunami. The tsunami killed 12, injured 54 (one gravely), damaged 37 homes (15 completely destroyed) and 25 boats (2 destroyed). Some of the fatalities were to line fishermen who were caught on the rocks by the waves. Additional fatalities occurred in the area of Santa, north of Coishco and at the beach of Campo Santa. More details below.

Tectonic Setting and Seismicity of the Central and Northern Peru Region

The Peru-Chile Trench - also known as the Atacama Trench - is the active boundary of collision of the Nazca Plate with the South American Plate. Subduction of the Nazca plate beneath the South America continent is not homogeneous. As a resut , asperities and structural complications have caused segmentation along the entire margin, resulting in zones with different rates of slip, seismic activity, volcanism, uplift, terracing and orogenic processess. Different sections of the margin along the Great Peru-Chile Trench, are segmented by great fractures. Each segment has its own characteristic parameters of collision and structural geometry and, thus, different potential for large earthquakes and destructive tsunamis.

The February 21, 1996 earthquake occurred along an area of high seismicity off the west coast of Northern/Central Peru, near the latitude of Chimbote. It was caused by reverse thrust faulting and uplift on the landward side of the Peru-Chile Trench on the over-riding tectonic plate - along the boundary where the Nazca plate subducts beneath the South American plate under extreme compressive force. However, the structure of the subducting oceanic Nazca plate is complex (Pedoja et al. 2003). According to Le Pichon et al. (1973), the velocity of subduction of the Nazca plate near the south Chile and north Peru region is about 8.7 - 8.8 cm/y.

Seismicity of the Central and Northern Peru Region - The historical record supports that the rate of subduction is not uniform and there is significant fragmentation along the entire length of the margin as well as differential uplift of the continental block. Certain tectonic block segments along the Peru-Chile tectonic boundary have the capability to generate very large earthquakes. In recent times, large earthquakes in regions of high rate of subduction have resulted in uplifting and terracing sections of the South American coast by as much as a few meters. Marine terraces and evidence of tectonic segmentation is also evident along the entire North Peruvian and Ecuadorian active margin. The ongoing process is responsible for the active orogenesis that is taking place and has created the young Andean mountain range.

Strong, destructive earthquakes and active orogenesis are evident off Northern/Central Peru between the Mendana Fracture Zone (MFZ) and the Nazca Ridge. Even though the Nazca Plate appears to be subducting smoothly and continuously at about 7-9 cm/yr into the Peru-Chile trench in this region of Northern/Central Peru, the deeper parts of the subducting plate appear to break into smaller pieces that become locked in place for long periods of time before generating large earthquakes.

The February 21, 1996 earthquake occurred along one of three distinct seismic zones in the Peruvian upper mantle (Ocola, 1966, Pararas-Carayannis, 1974). The seismic activity of this zone is most pronounced between the Andean Mountain block and the Peru-Chile trench. This narrow seismic band (100 to 150 km wide) is under Peru's Continental Shelf and is characterized by shallow earthquake activity and has great tsunamigenic potential (Pararas-Carayannis, 1968, 1974).

The region (from 7.5 to 12.5 degrees South latitude) has produced at least seven destructive earthquakes in the vicinity of Chimbote and Lima-Callao. These occurred on: 9 July 1586; 13 November 1655; 20 October 1687; 28 October 1746; 30 March 1828; 24 May 1940 (M = 8.4); and 17 October 1966 (M = 7.5) (Pararas-Carayannis, 1974). Of these, the earthquakes of 1586, 1687, 1746, 1828 and 1966 are documented to have produced destructive tsunamis (lida el al., 1968, Pararas-Carayannis, 1974).

The seismicity of this particular region can be expressed taking into account , not only the number of recorded past events but also their size, frequency, and spatial distribution (Pararas-Carayannis, 1974). For example, Ocola (1966) processed all earthquakes which occurred in the area during a 14 1/2-year period and prepared an earthquake energy release map which illustrates quite well the seismicity of this particular region. This map was prepared using the empirical relationships of earthquake energy, magnitude, and frequency, derived by Gutenberg and Richter (1956), by plotting the energy release of equivalent earthquakes of magnitude 4 (Richter scale). The figure provided here is a section from Ocola's map showing the earthquake energy release off the coast of central Peru from January 1949 to July 1963. The energy density contours are in units of 10 raised to the 19th power of ergs per 1 degree of latitude by 1 degree of longitude, for the 14 1/2-year period. The 1966 earthquake occurred within the band of highest activity shown in this figure. The February 21, 1996 earthquake also occurred within this band.

Although this map was prepared more than 40 years ago, and for a relatively short time interval, earthquake events which have occurred since - including the February 21, 1996 event - do not show significant change in the seismicity pattern in this region of Central and Northern Peru.

The orientation of the contours of energy release indicate general trends striking N30W, and are in agreement with the general trend of the fault systems, the Andean Mountains, and the alignment of the Peru-Chile trench in this Central and Northern region of Peru. Specifically, the Peru-Chile trench in this region is oriented at about N30W and the northern part of the Andean Mountains are oriented at about N32W. Similarly, major outcrops of intrusive rocks along the coast have general orientations at N20W and N55W. The fault plane parameters calculated by Harvard University for the February 21, 1996 earthquake have similar azimuthal orientation. The distribution of earthquake aftershocks for this event appear to parallel the Peruvian coastline, also with similar orientation.


Earthquakes with slow rupture rates, also known as "tsunami earthquakes" - or often as "silent earthquakes" - appear to be efficient tsunami generators. Such earthquakes do not produce intense ground motions and often are not strongly felt. Such a silent earthquake struck Central America in 1992 and generated a destructive tsunami in Nicaragua, Costa Rica and elsewhere in Central America. It cought people by surprise because its ground motions were not significant.

The earthquake of 21 February 1996 had a rupture of moderate speed which suggests that it occurred within compacted sediments along the tectonic margin region. Perhaps it was this reason that its ground motions were not strongly felt. The earthquake, although of moderate magnitude, generated a disproportionally large tsunami which had a maximum runup in excess of 5 meters.

Source area and observed coastal wave height distribution of the February 21, 1996 Peru Tsunami. Epicenters of the main shock are shown as reported by different agencies. {Modified Graphic of Tsunami Laboratory (Institute of Computational Mathematics and Mathematical Geophysics, Novosibirsk, RUSSIA)}. Superimposed are the Source mechanism as determined by Harvard University and the Estimated Generating Areas of the 1996 and 1966 tsunamis and length of earthquake ruptures (about 120 Km) (Pararas-Carayannis, 1974, 1996).

The tsunami of 21 February 1996 did not generate a Pacific-wide tsunami but it affected 590 km of coastal area extending from Pascasmayo, in the department of La Libertad, to the Port of Callao, near the capital, Lima. As previously reported most of the deaths and damage were caused by the tsunami. Fortunately the waves struck in the early morning hours when there were not too many people along the waterfront. Also, the tsunami death toll and damage were mitigated by the mere coicidence that most regional ports in the region had been closed for five days prior to the tsunami because of a heavy storm and dangerous waves. For the same reason, several of the larger ships had seeked refuge to deeper waters offshore - thus minimizing potential losses.

The tsunami killed 12, injured 57 (one gravely), damaged 37 homes (15 completely destroyed) and 25 boats (2 destroyed). Some of the fatalities were to line fishermen who were caught on the rocks by the tsunamis. In all, the tsunami destroyed or damaged several houses and boats, caused some damaged to port and harbor facilities, ruined crops, and damaged the beachfront property of several resorts in the area.

Tsunami Travel Time - The tide gauge at Port of Chimbote showed that the first wave arrived shortly after 9:00 a.m. (local time) - which indicates a tsunami travel time of about 70 minutes from the source region.

Eyewitness Reports - According to coastal residents the tsunami's arrival was preceeded by a marked withdrawal of the sea. The tsunami was described as progressive flooding of the coast by three waves in rapid succession. There was no breaking of the waves. The second of the waves was reported as being the highest. According to Peruvian Civil Defense, the citizens of Chimbote (located closest to the epicenter) evacuated the waterfront area when they noticed the withdrawal of the water from the shore. However, it is unclear whether people in other smaller coastal communities recognized or knew of the impending tsunami natural warning signs.

Near Field Tsunami Effects and Runup

The tsunami was destructive locally. The near field effects and the runup of the tsunami were extensively surveyed in March of 1996 by an International Team of scientists from Peru, Canada, and USA. Their findings were subsequently reported in the literature (Bourgeois et al. 1999). The team conducted interviews with local residents and reported the following tsunami runup values for the Chimbote region. For more details regarding this field survey, please refer to the reference for Bourgeois et al, 1996 or visit the University of Southern California Research Group Website at

Chimbote - At the Port of Chimbote, on the north side of Chimbote Bay, tsunami waves inundated 800 m landward of the main dock, overturned a truck, beached small boats, and transported a steel guard shack for a distance of about 20 m. However, no major damage to other structures occurred in the Bay. The University of California team which surveyed the area subsequently reported that the highest runup of 5.14 meters was measured there. As mentioned, the port had been closed for five days prior to the tsunami due to high storm wave conditions and that prevented losses of life in Chimbote Bay.

The normal tide variation for Chimbote is approximately 1m. The corrected maximum runup that was recorded was 2.8 m. Altough the tsunami innundated the beach in the bay, it did not damage structures.

Samanco Bay - At Samanco Bay, immediately south of Chimbote, the tsunami transported boats as far as 300 meters inland. The most dramatic runup effect occurred at a tomblo (low strip of land connecting a headland to the mainland) separating Chimbote and Samanco Bays, where the tsunami inundated the entire 1.5-kilometer wide by 4.5-kilometer long tombolo.

Coishco - According to the survey, the tsunami runup exceeded 5 meters at the town of Coishco, to the north of Chimbote. According to reports, a 30 meter long brick wall was destroyed and several houses along the waterfront were damaged by the waves. Additional fatalities occurred in the area of Puerto Santa, just north of Coishco and at the beach of Campo Santa. The dead included 6 fishermen near Coishco , four people who were gathering firewood near the mouth of the Santa River, and two children looking for gold on the beach at Cameo Santa.

Bahia Los Chimus - There was flooding at Bahia Los Chimus, about 30 Km south of Chimbote all the way to the town's plaza.

Casma - Further south of Chimbote, according to the survey, the tsunami runup at Casma and the vicinity ranged from 1.8 m to as much as 3.48, just north of the town.

Casma to Puerto Supe - The tsunami runup ranged from .85 meters to a maximum of 4.59 m. At Puerto Supe the tsunami runup was determined by the survey team to be 1.89 meters.

Pacasmayo to Chimbote - Further North of Chimbote and over a total distance of about 300 km. the tsunami runup ranged from 0.86 to a maximum at 3,46 meters between Trujillo and Salaverry.

Small tsunami Recorded by Distant Tide Gauge Stations - The tsunami was recorded by mid-Pacific tide gauges. It was 60 cm at Easter Island, and 25 cm at Hilo, Hawaii.

Tsunami Energy - Given the similarities of the source dimensions and magnitude of the 21 February 1996 earthquake with that of the 17 October 1966 earthquake in the same general area, the energy of the earthquake is estimated to be 1.12X 10 (raised to the 23 power) ergs. Similarly the combined energy release of the aftershocks is estimated to be 2.357 X 10 (raised to the 20th power) ergs. It is estimated that the 21 February 1996 tsunami was generated by ocean floor displacements which affected close to 13,000 sq. Km. Thus the energy that went into tsunami generation is estimated to be 6.8X10 (raised to the 19th power ergs) or approximately 1/1,650 of the total energy of the earthquake.

Past Earthquakes and Tsunamis in the Northern Peru Region

The Earthquake and Tsunami of 17 October 1966 - A similar earthquake to the 21 February 1996 occurred on 17 October 1966, The 1966 earthquake had a similar magnitude of 7.5 but sightly south and closer to the Peru's coastline. The epicenter of the 1966 earthquake quake was at 10.7 S Latitude and 78.7°W Longitude off the coast of Pativilca of Central Peru, 190 Km northwest of Lima (U. S. C & GS, 1966). Its focal depth was 60 Km deep. The earthquake affected a coastal belt 400 Km long and less than 50 Km wide, and severely damaged the towns of Huacho, Huaura, Puente Piedra and sectors of Lima-Callao. The highest intensity was observed in the vicinity of Huaura and may be related to a fault between Upper Jurassic and Lower Cretaceous sediments (Lommitz and Cabre', 1968). Effects of high intensity were also observed near the outlets of rivers and other areas of recent alluvium deposits.

The quake generated a large tsunami which caused destruction along the Peruvian coast from Chimbote in the North to San Juan in the South. (Pararas-Carayannis, 1968.) The greatest wave at Callao had a range of 3.40 m height (range between maximum crest and trough) and tsunami waves exceeding 3 meters in amplitude (height above undisturbed water level) inundated La Punta, Chuito, Ancon, Huaura, Huacho, and the resort of Buenos Aires in the City of Trujillo. Within 60-70 minutes after the quake, tsunami waves arrived at the cities of Chimbote and San Juan, which are about 800 Km apart. Devastating effects were experienced at Casma and Calota Tortuga where waves exceeding 6 meters in range destroyed many structures. (Pararas-Carayannis, 1968.) The port of Casma, about 360 Km north of Lima, suffered the greatest damage. Losses from this tsunami were estimated at about $4 million (1966 dollars) (40 million Peruvian Soles. Many fish-flour factories and the harbor wharf were severely damaged. Tsunami destruction also occurred at Puerto Chimu and Culebras (El Commercio de Lima, Peru, 18, 19 October 1966). The tsunami caused no damage outside Peru, but was recorded by tide gauges throughout the Pacific Ocean. (Beckman and Carrier, 1967).

Historical Tsunamis in the Central/Northern Peru Region

(Source: Iida, Cox, Pararas-Carayannis, 1967)

1586, 9 July - 0 30 Reconstructed Epicenter - 12.20 South 77.70 West, Off Lima/Callao, Peru. Reconstructed Magnitude 8.5 3.5 4.0 26.00 5 L 20 T 4 Destructive Tsunami. The shore inundated for 10 km inland. Tsunami Height at Trujillo 26 meters.

1655, 13 November - 19 38 Reconstructed Epicenter 12.00 South, 77.00 West, Off Lima/Callao. No details.

1678, 17 June - No details. At Santa sea receded and later returned with destructive violence. Ship carried far inland (alternate date given January 18)

1687, 10 20 - 9 30 Reconstructed Epicenter 13.50 South, 76.50 West Magnitude 8.5 3.5 1.0 8.00 14 M 5000 T 4 SAM LOC Off Callao. At Callao and Chancai Pisco, the sea retreated then returned with great violonce. Town and market were destroyed. No other details.

1746, 10 29 - 3 30 Reconstructed Epicenter 12.50 South, 77.00 West, Magnitude 8.0 3.5 4.6 24.00 7 L 18000 T 4

Near Callao the tsunami height was 24 meters. Portion of the coast sank producing a bay. All ships in the harbor were destroyed or beached. One ship stranded about 1.5 km inland. Of 5,000 inhabitants only 200 survived. At Cavallos, Chancay and Gaura the effects of the tsunami were similar.

1828 3 30 - 12 35 Reconstructed Epicenter 12.10 South, 77.80 West 50 8.2 No details available. Only that the tsunami was destructive to cities north of Lima (Callao).

1940 5 24 - 16 33 Epicenter 10.50 South, 77.00 West 60 8.4 7.8 1.5 1.0 2.00 1 S 250 T 3 No details available

1942 August 24 - Epicenter 15 South 76 West, Magnitude 8.1 Shallow. Tsunami at Callao - 1.6meter wave with period of 30 min. Travel time to Callao 0.7 hour; At Matarani 0.5 meters, Travel Time 1.7 hour. Tsunami wave period 21 min.

1966 10 17 - 21 42 Epicenter 10.70 South, 78.80 West 38 7.8 8.1 8.2 1.5 1.6 3.00 67 M 125 T 4

Tsunamigenic Potential of Central/Northern Peru - Future Impact

Tsunamigenic earthquakes with magnitudes up to 7.8 - similar to that of February 21, 1996 and of October 17, 1966 - are possible for the region of Central/Northern Peru and will occur again in the future. Based on stresses generated by the present rates of subduction of the Nazca plate below the South American plate, such large tsunamigenic earthquakes could occur on the average of every 30-40 years.

Also, since subduction in this northen region off Peru is not homogeneous - and there is apparent locking of tectonic blocks - a large earthquake can be expected in the future further north from the region affected by the 1966 and the 1996 tsunamigenic earthquakes. According to Erik Flesch (Department of Geosciences, University of Arizona) further north - between the Carnegie Ridge off Ecuador and the Mendana Fracture Zone (MFZ) off northern Peru - there has been a seismic gap of at least two hundred years. This seismic gap could be the source region for future large earthquakes (perhaps with magnitudes up to 7.8) that could generate destructive tsunamis that could affect the coastlines of northern Peru and southern Ecuador. However, the geometry of subduction and the segmentation of the tectonic blocks in this gap region is such that would most likely limit the lengths of ruptures of such earthquakes to perhaps no more than 150 km - which would also limit the far field effects of potential tsunamis from this particular gap region of the Peru-Chile Trench.

The Central/Northern Peru Region along the Peru-Chile Trench - bounded by the Mendana Fracture Zone (MFZ) to the North and the Nazca Ridge to the South - has unique mechanisms of generating destructive local tsunamis but historically has not generated tsunamis with far reaching Pacific-wide effects. However, segments further south of the Nazca Ridge (closer to Arica, Latitude 18-20 South), the region off Central Chile and and even further south than the Juan Fernandez Ridge, have different structural geometries and can generate great earthquakes with greater ruptures and tsunamis with far reaching, Pacific-wide impact. One example would be the segment between 15 and 18 degrees South latitude which generated the 1868 Pacific-wide tsunami. Another segment would be from the Chiloe Fracture Zone to the Taitao Fracture Zone, where the great Chilean earthquake of May 22, 1960 occurred (with epicenter at 39.50 South, 74.30 West). The rupture of this earthquake and the tsunami generating area extended all the way past the Darwin Fracture Zone (about 46 South latitude) to Chile's triple point junction with the Antarctic plate near the Taitao Fracture Zone. The potential for large or great earthquakes that could generate Pacific-wide tsunamis along South America will be further discussed in a future analysis.


Berckman, C. S. and Carrier, D. D., 1967; "The Tsunami of October 17, 1966, as Recorded by Tide Gages". Tides Branch, U. S. Coast and Geodetic Survey Informal Pamphlet, 8 March.

Beck, S., and G. Zandt (2002). The nature of orogenic crust in the central Andes, J. Geophys. Res. 107(B10), 2230.

Berninghausen W.H., Tsunamis Reported from the West Coast of South America 1562-1960, Bull. of Seismol. Soc. Am. 52(4), pp. 915 - 921

J. Bourgeois, C. Petroff, H. Yeh, V. Titov, §, C. E. Synolakis, B. Benson, J. Kuroiwa, J. Lander, E. Norabuenam, 1999.
Geologic Setting, Field Survey and Modeling of the Chimbote, Northern Peru, Tsunami of 21 February 1996. Journal of Pure and Applied Geophysics, Earth and Environmental Science Issue, Volume 154, Numbers 3-4 / May, 1999, Pages 513-540

Fisher, R. L. and Raitt, W. R. (1962); "Topography and Structure of the Peru-Chile Trench", Deep Sea Res., 9, 423-443.

Dorbath, L., Cisternas, A., and Dorbath, C. 1990, Assessment of the Size of Large and Great Historical Earthquakes of Peru, Bull. Seismol. Soc. Am. 80(3), pp. 551 - 576.

Giovanni, M., S. Beck, and L. Wagner 2002). The June 23, 2001 Peru Earthquake the southern Peru subduction zone, Geophys. Res. Lett. 29(21), 2018, doi:10.1029/2002

Gutenberg, B. and Richter, C. F., 1956. Earthquake magnitude, intensity, energy , acceleration, 2. Bull. Seismo!. Soc. Am., 46 (2):105-143.

Iida, K., D. Cox and G. Pararas-Carayannis, 1968; "Prelim. Catalogue of Tsunamis Occurring in the Pacific Ocean", Hawaii Institute of Geophysics, Univ. of Hawaii, Data Rept. No. 5.

Lockridge, P.A., 1985 Tsunamis in Peru-Chile, World Data Center A for Solid Earth Geophysics Report SE-39, 97 pp.

Lomnitz, C., and Cabre' R. 1968, "The Peru Earthquake of October 17, 1966", Bull. Seism. Soc. Am., Vol. 58, No. 2, pp. 645-661, April.

Newman A.V., and Okal, E.A., 1996, Source Slowness of the February 21, 1996 Chimbote Earthquake Studied from Teleseismic Energy Estimates, EOS 77(17), S184.

Ocola, L., 1966. "Earthquake Activity of Peru", Am. Geophys. U., Geophys. Monograph 10, 509-528.

Pararas-Carayannis, G. 1968, "The Tsunami of October 17, 1966 in Peru", International Tsunami Information Center Newsletter, Vol. 1, No. 1, March 5.

Pararas-Carayannis, George. 1974, An Investigation of Tsunami Source Mechanism off the Coast of Central Peru. Marine Geology, Vol. 17, pp. 235-247, Amsterdam: Elsevier Scientific Publishing Company, 1974.

Pararas-Carayannis, G. and Calebaugh P.J., 1977. Catalog of Tsunamis in Hawaii, Revised and Updated , World Data Center A for Solid Earth Geophysics, NOAA, 78 p., March 1977.

K. Pedoja, J.-F. Dumont, M. Lamothe and Auclair, M. 2003. MARINE TERRACES ON THE NORTH PERUVIAN AND ECUADORIAN ACTIVE MARGIN: TECTONIC SEGMENTATION, Geophysical Research Abstracts, Vol. 5, 12200, 2003 European Geophysical Society

W. Spence, C. Mendoza, E. R. Engdahl, G. L. Choy, E. Norabuena, 1999. Seismic Subduction of the Nazca Ridge as Shown by the 1996­97 Peru Earthquakes. JournalPure and Applied Geophysics, Earth and Environmental Science
Issue, Volume 154, Numbers 3-4 / May, 1999Pages, 753-776.

Swenson, J. L. and S. L. Beck 1999.
Source characteristics of the 12 November 1996 MW 7.7 Peru subduction zone earthquake, PAGEOPH 154(3-4), 731-751.



Pararas-Carayannis, G. Earthquake and Tsunami of 23 June 2001 in Southern Peru

University of Southern California Research Group Website, The 1996 Chimbote Tsunami

Return to

Links to other Pages

The Big One - The Next Great California Earthquake (A new edition of the book)

Now available from Amazon, Barnes and Noble and other major bookstores. A signed by the author copy can be also ordered by contacting directly by email Aston Forbes Press.

Other Miscellaneous Non-technical Writings

(©) Copyright 1963-2007 George Pararas-Carayannis / all rights reserved / Information on this site is for viewing and personal information only - protected by copyright. Any unauthorized use or reproduction of material from this site without written permission is prohibited.
Web Site Created By Dr. George Pararas-Carayannis / Copyright © 2000. All Rights Reserved

Template Courtesy of "Budget Office & Facility Supply"