The 1985 Mexico City earthquake struck in the early morning of 19 September at 07:17:50 (CST) with a moment magnitude of 8.0 and a Mercalli intensity of IX (Violent). The event caused serious damage to the Greater Mexico City area and the deaths of at least 5,000 people.
Most of the earthquake damage was to buildings. Two reasons are the resonance in the lakebed sediments and the long duration of the shaking. The buildings most damaged were from 6 to 15 stories in height. These buildings tended to resonate most with the energetic frequency band of the lakebed motions.
10 biggest earthquakes in recorded history
- Valdivia, Chile, 22 May 1960 (9.5)
- Prince William Sound, Alaska, 28 March 1964 (9.2)
- Sumatra, Indonesia, 26 December 2004 (9.1)
- Sendai, Japan, 11 March 2011 (9.0)
- Kamchatka, Russia, 4 November 1952 (9.0)
- Bio-bio, Chile, 27 February 2010 (8.8)
Earthquake shakes Mexico City. On September 19, 1985, a powerful earthquake strikes Mexico City and leaves 10,000 people dead, 30,000 injured and thousands more homeless. At 7:18 in the morning, the residents of Mexico City were jolted awake by an 8.1-magnitude earthquake, one of the strongest to ever hit the area.
On September 19, 1985, a powerful earthquake strikes Mexico City and leaves 10,000 people dead, 30,000 injured and thousands more homeless. At 7:18 in the morning, the residents of Mexico City were jolted awake by an 8.1-magnitude earthquake, one of the strongest to ever hit the area.
Mexico City earthquake of 1985, also called Michoacán earthquake of 1985, severe earthquake that occurred on September 19, 1985, off the coast of the Mexican state of Michoacán, causing widespread death and injuries and catastrophic damage in Mexico's capital, Mexico City.
2017 Puebla earthquake. The 2017 Puebla earthquake struck at 13:14 CDT (18:14 UTC) on 19 September 2017 with an estimated magnitude of Mw 7.1 and strong shaking for about 20 seconds.
The primary effects of earthquakes are ground shaking, ground rupture, landslides, tsunamis, and liquefaction. Fires are probably the single most important secondary effect of earthquakes.
List of earthquakes in 2020
| Number by magnitude |
|---|
| 7.0−7.9 | 3 |
| 6.0−6.9 | 27 |
| 5.0−5.9 | 381 |
| 4.0−4.9 | 2,861 |
The 1985 Mexico City earthquake struck in the early morning of 19 September at 07:17:50 (CST) with a moment magnitude of 8.0 and a Mercalli intensity of IX (Violent). The event caused serious damage to the Greater Mexico City area and the deaths of at least 5,000 people.
On September 19, 1985, a powerful earthquake strikes Mexico City and leaves 10,000 people dead, 30,000 injured and thousands more homeless. At 7:18 in the morning, the residents of Mexico City were jolted awake by an 8.1-magnitude earthquake, one of the strongest to ever hit the area.
The border between the Cocos Plate and North American Plate, along the Pacific Coast of Mexico, creates a subduction zone that generates large seismic events. Mexico City is built on a dry lakebed with soft soil made up of sand and clay, which amplifies the destruction that major earthquakes cause.
The event caused between three and four billion USD in damage as 412 buildings collapsed and another 3,124 were seriously damaged in the city.
One of the worst natural disasters in the Americas occurred 23 years ago today, when at 7:19 am local time an earthquake of magnitude 8.1 struck in the subduction zone off the west coast of Mexico. The epicenter was located approximately six miles offshore near the town of Zihuatanejo in the state of Michoacan.
At least 220 people were killed in a magnitude 7.1 earthquake that rattled Mexico on Tuesday, toppling buildings and leaving people trapped under rubble.
The epicenter is the point on the surface of the Earth directly above the hypocenter of an earthquake. The hypocenter is the place where the rupture of the plate boundary that led to the earthquake first happened.
Earthquakes are usually caused when rock underground suddenly breaks along a fault. This sudden release of energy causes the seismic waves that make the ground shake. The rocks are still pushing against each other, but not moving. After a while, the rocks break because of all the pressure that's built up.
Mexico is one of the most seismically active countries in the world. Over the past century, the country has seen 19 earthquakes within 155 miles of the epicenter of last year's earthquake, according to the US Geological Survey.
Quakes also cause electrical power lines to break, as poles are tipped, making sparks which start fires wherever there is flammable material. Quakes also cause electrical power lines to break, as poles are tipped, making sparks which start fires wherever there is flammable material.
Mexico qualifies as highly active. The country sits at the boundary of three pieces of the Earth's crust that fit together like a jigsaw puzzle — called tectonic plates. Today's quake originated on a fault within the Cocos plate, which is on Mexico's western edge.
Liquefaction takes place when loosely packed, water-logged sediments at or near the ground surface lose their strength in response to strong ground shaking. Liquefaction occurring beneath buildings and other structures can cause major damage during earthquakes.
There are two primary scales used to measure earthquakes: the Richter scale and the Mercalli scale. The Richter scale is most common in the United States, while worldwide, scientists rely on the Mercalli scale. The moment magnitude scale is another earthquake measurement scale used by some seismologists.
The country sits atop three of the Earth's largest tectonic plates — the North American plate, the Cocos Plate, and the Pacific Plate.
The September 19, 2017, earthquake in Mexico released strain pent up from the ongoing collision between the Cocos plate, which carries the Pacific ocean floor south of Mexico, and the North American plate to the northeast. Most earthquakes arise along such fault zones.
This is what causes “bending” earthquakes like Mexico City's. After the bent tectonic plate snaps, seismic waves emanate outwards from the breaking point, causing the Earth to tremble. The closer you are to the epicenter, the stronger the shaking.
New Madrid Region (1811-1812)
Between December 16, 1811, and March 15, 1812, a series of devastating earthquakes struck the interior of the continental United States. The series defined the New Madrid Seismic Zone, named after New Madrid, Missouri, which was the town closest to the epicenter of the earthquake sequence.Francisco Hernández de Córdoba
The northern boundary of the Cocos Plate is the Middle America Trench. The eastern boundary is a transform fault, the Panama Fracture Zone. The southern boundary is a mid-oceanic ridge, the Galapagos Rise. The western boundary is another mid-ocean ridge, the East Pacific Rise.
