1995 Colima-Jalisco earthquake
Encyclopedia
The 1995 Colima-Jalisco earthquake was a Mw
Moment magnitude scale
The moment magnitude scale is used by seismologists to measure the size of earthquakes in terms of the energy released. The magnitude is based on the seismic moment of the earthquake, which is equal to the rigidity of the Earth multiplied by the average amount of slip on the fault and the size of...

 8.0 earthquake which occurred on October 9 at 15:36 UTC, off the coast of Jalisco
Jalisco
Jalisco officially Estado Libre y Soberano de Jalisco is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is located in Western Mexico and divided in 125 municipalities and its capital city is Guadalajara.It is one of the more important states...

, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

. At least 49 people died and 100 were injured because of the earthquake
Earthquake
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...

. The earthquake triggered a tsunami
Tsunami
A tsunami is a series of water waves caused by the displacement of a large volume of a body of water, typically an ocean or a large lake...

, which affected a 200 km stretch of the coast. The Cihuatlan-Manzanillo area, Colima
Colima
Colima is one of the 31 states which, with the Federal District, make up the 32 Federal Entities of Mexico. It shares its name with its capital and main city, Colima....

, was more severely affected than other areas. The earthquake could be felt in Mexico City
Mexico City
Mexico City is the Federal District , capital of Mexico and seat of the federal powers of the Mexican Union. It is a federal entity within Mexico which is not part of any one of the 31 Mexican states but belongs to the federation as a whole...

 and in high-rise buildings in Dallas and Houston. The intensities in Colima and Jalisco reached MM VI.

Tectonic setting

This earthquake occurred in the area where the Rivera Plate
Rivera Plate
The Rivera Plate is a small tectonic plate located off the west coast of Mexico, just south of the Baja California Peninsula. It is bounded on the northwest by the East Pacific Rise, on the southwest by the Rivera Transform Fault, on the southeast by a deformation zone, and on the northeast by...

 subducts
Subduction
In geology, subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate, sinking into the Earth's mantle, as the plates converge. These 3D regions of mantle downwellings are known as "Subduction Zones"...

 beneath the North American Plate
North American Plate
The North American Plate is a tectonic plate covering most of North America, Greenland, Cuba, Bahamas, and parts of Siberia, Japan and Iceland. It extends eastward to the Mid-Atlantic Ridge and westward to the Chersky Range in eastern Siberia. The plate includes both continental and oceanic crust...

. It was the result of the relative movements between the North American Plate, the Rivera Plate, and the Cocos Plate
Cocos Plate
The Cocos Plate is an oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America, named for Cocos Island, which rides upon it.-Geology:...

.

Damage

Although the tsunami affected a 200 km stretch of coast, severe damage was confined to areas with shallow shoreline topography. Most of the flooding occurred in the Tenacatita Bay
La Manzanilla, Jalisco
La Manzanilla is a small Mexican town of approximately 2,000 inhabitants. The village is located in the southeastern corner of the Bay of Tenacatita, on the Costalegre of southwestern mainland Mexico in the state of Jalisco. "Manzanilla" is Spanish for chamomille.The town is a popular beach...

 area. Landslides blocked roads between Guadalajara
Guadalajara
Guadalajara may refer to:In Mexico:*Guadalajara, Jalisco, the capital of the state of Jalisco and second largest city in Mexico**Guadalajara Metropolitan Area*University of Guadalajara, a public university in Guadalajara, Jalisco...

 and Manzanillo
Manzanillo, Colima
The name Manzanillo refers to the city as well as its surrounding municipality in the Mexican state of Colima. The city, located on the Pacific Ocean, contains Mexico's busiest port. Manzanillo was the third port created by the Spanish in the Pacific during the New Spain period...

. In Manzanillo, 18 people died in the collapse of an eight-story hotel.

Earthquake

The earthquake rupture lasted for about a minute and involved a 200 km long break along the plate boundary. The greatest displacement of the fault is about 5m. A 14 cm subsidence occurred at Manzanillo.

The variations in observed seismic intensity indicate that three asperities were ruptured during this event.

Tsunami

The tsunami had a maximum run-up height of 5.1 m. There were at least two waves recorded. The tsunami was also observed in Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...

, French Polynesia
French Polynesia
French Polynesia is an overseas country of the French Republic . It is made up of several groups of Polynesian islands, the most famous island being Tahiti in the Society Islands group, which is also the most populous island and the seat of the capital of the territory...

, Samoan Islands
Samoan Islands
The Samoan Islands or Samoa Islands is an archipelago covering in the central South Pacific, forming part of Polynesia and the wider region of Oceania...

, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

 and Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

.

Postseismic moment release

Postseismic deformation has been recorded after the main shock. If the postseismic moment release up to about two weeks after the main shock is included, it will be equivalent to 35% of that of the main shock, which will make the additional seismic moment equivalent to that of an Mw 7.7 earthquake.
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