We explain everything about the 1985 Mexico earthquake, its main causes, consequences and general characteristics.
The 1985 Mexico earthquake had a magnitude of 8.1.
What was the 1985 Mexico earthquake like?
The 1985 Mexico earthquake was a seismic movement that occurred on Thursday, September 19, 1985 starting at 7:17 a.m. (local time) and whose epicenter was located on the Mexican Pacific coast, in the state of Michoacán.
Quake reached a magnitude of 8.1and was the most destructive and deadly in the history of Mexico. It affected numerous cities in the center, south and west of the country, including Mexico City, and surpassed the 1957 earthquake that had been the largest earthquake suffered in the region until then.
The direct consequences of the 1985 earthquake were catastrophic., in terms of fatalities, injuries, destroyed infrastructure and subsequent reconstruction difficulties. The next day, an aftershock of similar magnitude devastated structures already weakened by the first movement.
Earthquake was particularly damaging to Mexico Citycapital of the republic, due to the characteristics of the land on which it was built.
The magnitude of the earthquake in Mexico
The earthquake shook the states of Michoacán, Jalisco, Guerrero and Mexico City.
The earthquake of September 19, 1985 reached a magnitude of 8.1 and It lasted almost four minutes.It was produced by the contact between the Cocos and North American tectonic plates in a subduction zone.
It began at 7:17 with an epicenter near the mouth of the Balsas River., between the states of Michoacán and Guerrero, and at a depth of 15 km. It shook the states of Michoacán, Jalisco, Guerrero and Mexico City. In the latter she felt at 7:19.
The aftershocks of the Mexico earthquake
The earthquake had several aftershocks. The most important of all occurred the next day, that is, on Friday, September 20, at 7:37 p.m. and with a magnitude of 7.6, with the epicenter in Zihuatanejo, in the state of Guerrero. In addition to aggravating the damage from the previous day, this earthquake produced a tsunami in Ixtapa-Zihuatanejo.
Another aftershock occurred on April 30, 1986., with a magnitude of 7.0 and epicenter in the state of Michoacán. Strikingly, on September 19, 2022, a major earthquake with a magnitude of 7.7 occurred in Michoacán, which affected several areas (including Mexico City) and coincided with the date of the first earthquake of 1985. The same day but of the year In 2017, an earthquake in Puebla with a magnitude of 7.1 also affected the capital city. However, these episodes had no geological relationship with the 1985 earthquake.
Victims and damages from the Mexico earthquake
Total damages were estimated at more than US$4 billion.
The total number of victims and injured from the 1985 earthquake is unknown. The official death toll was initially 3,692, but later official sources changed the figure. They estimated between 6,000 and 7,000 people died. Later estimates suggested the figure could be as high as 10,000, and unofficial figures suggest even higher numbers. The destruction of hospitals in the aftermath of the quake, especially in Mexico City, often prevented the injured from being treated.
Among those who survived, it is estimated that there were 30,000 injured and 250,000 affected people left homelessof which tens of thousands had to stay in camps and temporary shelters. Rescue efforts lasted for more than a month, and debris removal continued even ten years after the earthquake.
Property damage was estimated at more than US$4 billion. Mexico City was especially affected by the landslides, because it was largely built on a dry lake. More than 400 buildings collapsed and thousands were damaged. The city was cut off for a time, without electricity or telephone system.
The absence of immediate government measures generated a a feeling of helplessness among the population, which had to organize itself. All this, added to the initial rejection of the president of the republic, Miguel de la Madrid Hurtado, to receive international aid, weakened the public image of the government.
Rescuing the victims
The total number of rescued survivors was approximately 4,000 people.
The first Rescue work was carried out by the city’s own inhabitants.who were responsible for searching for and rescuing people buried under the rubble and distributing supplies. Those living in less affected regions travelled to critical areas to offer their help.
Subsequently, firefighter, police and armed forces units were mobilized, although The government of the republic was accused of acting slowly. The president initially rejected the offer of humanitarian aid from international organizations, but soon had to retract it and accept it.
Rescue efforts extended until weeks after the initial earthquake. People could be extracted alive from the rubble of destroyed buildings up to 10 days after the earthquake. The total number of rescued survivors was approximately 4000 people.
The lifeless bodies found were so many, and the work to recover them lasted for so long, that As of September 22, they were destined for mass graves in local cemeteries.
Initially They had been transferred to various delegations in the citybut these were collapsed due to the number of victims, and a baseball stadium began to be used (in the current Delta Park), where formaldehyde, lime and ice were used to delay the decomposition of the bodies that remained unrecognized. .
Humanitarian aid during the earthquake in Mexico
The collaboration of various countries to deal with the disaster was numerous: by mid-October 1985 they had traveled to Mexico 220 flights from 37 different countries with food, belongings, rescue tents, clothing, first aid material and volunteer personnel. The rescue material received between September 20 and October 9 totaled some 1,336 tons.
The administration of humanitarian aid by the government of Miguel de la Madrid Hurtado was a cause of suspicion and criticism, due to accusations of irregular distribution and mismanagement.
For this reason, the Supervisory Committee for Donations for Relief of Victims and Reconstruction of Affected Areas was created on October 3, with the aim of ensuring the correct distribution of donations.
Economic and social consequences of the Mexico earthquake
At least 30,000 homes were destroyed.
Quake left a balance of 250,000 victims. Among them, more than 30,000 were relocated to camps. These camps were so numerous that in 2015 some could still be found. Jobs lost are estimated at between 150,000 and 200,000, and the number of buildings destroyed in the city was approximately 400 (including hospitals and schools). This meant around 30,000 homes destroyed and almost 70,000 partially damaged.
The Mexican government had been dragging along an external debt and a critical economic situation that was aggravated by this catastrophe. Material losses were estimated at more than $4 billion. (at a cost to the economy of more than 8 billion dollars). At the end of 1985, the international price of oil, one of Mexico’s main exports, fell, so resources to rebuild the capital and generate employment were scarce. In the 1990s, some buildings in Mexico City were still in ruins.
In addition to material costs, numerous costs were reported situations of depression, collective psychosis, sleep disorders, post-traumatic stress and reactions of guilt or aggression that required the intervention of more than a thousand trainers from the Coordination of Psychiatry and Mental Health of the Mexican Social Security Institute.
Political consequences of the Mexico earthquake
The climate of disorganization that characterized the first hours of the rescue efforts and the slow and deficient government handling of the situation, They produced a lot of rejection to the management of the ruling party (Institutional Revolutionary Party, PRI).
In the face of the initial inaction of Miguel de la Madrid’s government, citizens (especially in Mexico City) organized themselves into a movement of voluntary rescue actions that wove networks of collective solidarity and strengthened community ties.
Shortly after the earthquake, the first protest movements demanding better care conditionshomes and basic service spaces.
It was created the Single Coordinator of Victims (CUD)an organization that brought together the demands of numerous groups of affected neighbors and that, gradually, constituted a set of popular protest and citizen organization movements that acquired political and social importance.
Due to pressure from these groups, the government was forced to expropriate some of the destroyed properties and build there. New housing for the victimsfor which it had the financial support of the World Bank.
Given the climate of social discontent and criticism of the ruling party, in 1986 An electoral reform was promoted that modernized the voting system and facilitated the participation of minority opposition political parties in the 1988 presidential elections.
Legal consequences of the earthquake in Mexico
Many structures were unsuitable for construction on clay soil.
Analysis after the earthquake allowed us to determine that Most of the collapsed buildings were of recent construction (30 years)while the main structures of previous centuries withstood the onslaught.
Many of the buildings that collapsed They showed structures that were unsuitable for being built on clay soil. like the one that characterized the soil in the most affected areas of Mexico City.
This fact exposed the absence of specific regulations that took into account the condition of the soil for the construction of buildings, and also the existence of numerous irregularities that pointed to poor planning and the endorsement of local authorities for non-compliance with regulations by builders.
However, There were no lawsuits against the buildersnot even against the state company that had been responsible for building schools.
Since the earthquake, The laws for building construction were tightened according to regulations to resist telluric movements. In addition, institutions were created to prevent and mitigate the effects of earthquakes, a network of seismic wave sensors was established and protocols were implemented that include carrying out…