Everything Everywhere Daily: History, Science, Geography & More - The 1970 Ancash Earthquake

Episode Date: September 21, 2025

On May 31, 1970, one of the most devastating disasters in Peruvian history occurred.  A magnitude 7.9 earthquake hit just off the coast of Peru, creating the most catastrophic natural disaster in the country's history.   The “Ancash” or “Great Peruvian Earthquake” not only caused disastrous short-term loss of life, but also had long-term impacts that shaped multiple spheres of Peruvian life for years to come.  Learn about the Ancash Earthquake and its devastating impact on this episode of Everything Everywhere Daily. Sponsors Quince Go to quince.com/daily for 365-day returns, plus free shipping on your order! Mint Mobile Get your 3-month Unlimited wireless plan for just 15 bucks a month at mintmobile.com/eed Stash Go to get.stash.com/EVERYTHING to see how you can receive $25 towards your first stock purchase. ExpressVPN Go to expressvpn.com/EED to get an extra four months of ExpressVPN for free!w Subscribe to the podcast!  https://everything-everywhere.com/everything-everywhere-daily-podcast/ -------------------------------- Executive Producer: Charles Daniel Associate Producers: Austin Oetken & Cameron Kieffer   Become a supporter on Patreon: https://www.patreon.com/everythingeverywhere Discord Server: https://discord.gg/UkRUJFh Instagram: https://www.instagram.com/everythingeverywhere/ Facebook Group: https://www.facebook.com/groups/everythingeverywheredaily Twitter: https://twitter.com/everywheretrip Website: https://everything-everywhere.com/  Disce aliquid novi cotidie Learn more about your ad choices. Visit megaphone.fm/adchoices

On May 31st, 1970, one of the most devastating disasters in Peruvian history occurred. A magnitude 7.9 earthquake hit just off the coast of Peru, creating the most catastrophic natural disaster in the country's history. The Oncash, or Great Peruvian earthquake, not only caused a disastrous loss of life, but also had long-term impacts that shape Peru for years to come. And it also showed, perhaps more than any other earthquake, it isn't how much the ground necessarily moves, but also what it moves. Learn more about the Oncash earthquake and its devastating impact on this episode of Everything

Everywhere Daily. Did you ever hear about the selfie that solved a murder or the jury that used a Ouija board to speak to a victim? If that made you pause, you need to listen to Morning Cup of Murder. I'm Karina B. Minasurfer, and every single day on Morning Cup of Murder, I tell one chilling true crime story tied to that exact day in history. With over 2,500 episodes to binge, you'll never run out of dark stories to start your morning with. Go listen to Morning Cup of Murder wherever you get your podcasts.

And remember, stay safe. Before I get into the details of the Ancash earthquake, I'd like to explain the geological conditions that makes Peru more susceptible to earthquakes when compared to other countries. Peru is located on the Pacific Ring of Fire. The Ring of Fire received its name from holding roughly two-thirds of the world's active voids. volcanoes and the Earth's greatest concentration of earthquakes. The volcanoes are located on tectonic boundaries, where two or more tectonic plates move against each other. If you recall my episode on volcanoes, these plates can rub against each other or be subducted below another plate. These plate boundaries can result in islands, mountains, volcanoes, and deep ocean ridges. A common side

effect of the movement of these tectonic plates is earthquakes. Earthquakes are a result of of sudden movements along geologic faults. This sudden shift releases energy as a seismic wave, which then makes the ground shake. Peru sits right on the fall line of the NASCA plate and the South American plate. The NASCA plate is oceanic, meaning its crust is more dense and therefore is subducting underneath the less dense continental crust of the South American plate. The tectonic activity of the NASCA and South American plates causes the South American plate to essentially be pushed upward and fold in on itself, creating the Andes Mountains, which is the mountain range that Peru sits on. The friction around the two plates leads to intense earthquake

activity occurring in Peru, especially in the western part of the country. The upshot of all of this is that many Peruvians are in areas that are more prone to natural disasters, including earthquakes, tsunamis, mudslides, and avalanches. And with that, on to the subject of this episode. The Oncash, or Great Peruvian earthquake, hit Peru on May 31, 1970, at approximately 2.23 p.m. local Peruvian time, with the magnitude being reported at a 7.9 on the Richter scale. 7.9 is certainly considered a major earthquake, but it is far from the largest. The earthquake occurred roughly 25 kilometers off the coast of the Peruvian city of Chimbote. Eyewitness accounts stated that the earthquake began without prior warning as a gentle

swaying motion that lasted for a few seconds and was later followed by hard shaking estimated as lasting from 30 to 90 seconds. This earthquake impacted an area of roughly 83,000 square kilometers. Or to put that number in a perspective, it would be larger than the combined area of Belgium and the Netherlands. The effects on the area were devastating, especially to the Ankaish and La Libertad regions of the country. But the most shocking impact was in the town of Yungai. Yungai was located in the Cajajon de Huayas Valley of Peru,

which is right between the Pacific Ocean and the Andes Mountain Range. When the earthquake occurred, Wascaran Mountain, the highest point in Peru and part of the Cordillera Blanca Mountain Range, had a massive glacier and a large amount of snow mass that became destabilized. What followed was the glacier and snow rapidly surging down the mountain and turning into mud while picking up large amounts of loose dirt, water, and rocks. This created a massive avalanche.

When the earthquake initially hit Yungai, many residents of the city flocked to churches to prey during the disaster. The initial earthquake had already destroyed a good portion of the town's buildings. However, if that were all that happened, I wouldn't be doing an episode on it over 50 years later. What came next would be far more devastating, making the disaster one that would be remembered for ages. Young Guy was first hit with a large blast of air from the onrushing flow of material rushing down the mountain. It was followed by debris and boulders before the main semi-liquid wave arrived. The mud flow that was triggered by the avalanche sped into the city at an estimated speed

of 280 miles per hour or 335 kilometers per hour, instantly killing thousands of people. The exact number of people killed in Yungai varies based on source, but roughly 15 to 20,000 people in the city of Yungai died that day, leaving only 400 alive from the city of Yungai proper. Of those 400 survivors, roughly 300 were children who were attending a circus in a local stadium. A clown had led the children out of the stadium and on top of a hill in a nearby cemetery. The surrounding villages near Yungai met a similar fate, bringing the death toll to 30,000 people. It was the deadliest avalanche in world history by a wide margin, and would have been the deadliest natural disaster for the country since 1900 if that was the only thing that happened. Survivors of the Yungai disaster were moved to a refugee camp, which became known as Yungai Nort.

The city would eventually be relocated and rebuilt with the original Young Guy's location being declared a national cemetery. However, Yungai was not the only city affected as the earthquake impacted many other cities in Peru. Many of the coastal cities in the Ankash region, including Chimbote, Rekwai, and Karwaz had between 80 to 90% of their buildings completely destroyed as well. These cities were hit so hard because of their poor physical infrastructure. For example, the city of Chimbote had been a boomtown, growing from 1,500 people in 1950 to 134,000 people in 1970. This meant that a good portion of the city lived in shanty towns. These shanty towns were informal settlements with no access to things like sewage systems, electricity, or paved roads. Many of these buildings were made out of mud-dried bricks and immediately collapsed when the earthquake hit.

Other cities in Peru that were impacted had similar shanty-town setup. which is why the infrastructural damage was so drastic in these places. All in all, an estimated 66 to 70,000 people lost their lives between the earthquake and the avalanche, making the disaster by far the deadliest in the history of Peru. The rebuilding of the country would prove to be quite difficult. On top of destroying infrastructure, killing tens of thousands of people, and injuring countless more, the earthquake made rescue operations and aid distribution incredibly difficult. As many impacted cities and towns are located within the Andes Mountains,

the ability for aid to reach the area was exceptionally hard due to a large portion of the ground access into the mountains being completely blockaded by the avalanche. The problem was worsened by the dust in the air, making it difficult to conduct aerial reconnaissance in the impacted areas. Transporting necessary resources like food and medicine was also difficult for the government as many of the roads were destroyed by the earthquake. This meant getting those resources to affected areas, including to those on the coast, became a massive problem. Providing shelter

would also prove to be difficult for the government, as basically everything was destroyed. Many people were forced to sleep in military tents, refugee colonies, or amidst the rubble. The damage caused by the earthquake was over $530 million U.S. dollars, which is equivalent to roughly $4.4 billion today, with emergency relief for aid being sent to Peru from 60 countries. The aid helped ease conditions somewhat on the ground, but the earthquake exposed some of the fundamental problems within the country. Just two years before the earthquake occurred, Peru had a military coup. This resulted in the country being disorganized, which itself was an issue, but was exposed by the earthquake. After the Ankhash earthquake, the Peruvian government rightfully wanted to make sure that a disaster

of this type would never occur again, so they enacted a series of policy reforms. However, many of these policies were widely unpopular or outright backfired. And this can be best illustrated by what happened in the town of Chimbote. To create the best plan possible, Peru brought in geological experts from France and Japan. When testing the soil around Chimbote, they found that the soil was simply too unstable to settle on. This led the government to conclude that the best way to prevent a future disaster would be to relocate the city center. This would put the city center further south on more stable land, which was already owned by the state. This meant that the government could redistribute the land without bothering pre-existing landowners. While in theory, this sounded great,

in practice, this would involve relocating a quarter of a million people. Many of these people did not want to have to travel further for work, lose their neighborhoods, and rebuild their homes. Because of the massive public backlash, the government never enacted the plan and had to find another solution. The new plan was to give a large number of citizens within the shanty towns property titles, prioritizing those with kids. The goal of this initiative was to provide stability, particularly to family units in the area. With the stability of owning land, the government hoped that the citizens would rebuild their homes with better materials. Unfortunately for the government, this plan also backfired. Despite the

rebuilding effort, Chimbote was still a boom town and its population continued to skyrocket, growing at the same rate as before the earthquake. This meant that 75% of the people still lived in shanty towns. A large reason why this backfired was the land reform itself. By giving out property, it incentivized people to stay or to come to Chimbote. For many, the security of land was better than moving to an unknown area in a new city. Another issue the government faced was the disruption to the economy. In many of the impacted cities, the government faced a massive unemployment problem and was unable to supply new jobs.

About 50% of the labor force was unemployed, leaving many Peruvians frustrated with the government. Additionally, much of the foreign aid being provided went into fixing Peruvian industries rather than supporting the displaced population. Many people within Peru felt that the government's policies, which focused primarily on helping rich industrialists, ignored the specific problems actually caused by the earthquake, which, as you can expect, was highly unpopular. Another economic problem was how the government was going to pay for all this. One solution was to raise taxes, which they started hinting at, leading to pushback, forcing the government to drop the plan. In addition to the short-term problems the government faced, there were many long-term problems

from the earthquake as well. One long-term impact was the education levels of the generation that lived through the earthquake and their children. Even those who hadn't been born yet when the earthquake hit completed less school on average when compared to their non-impacted counterparts in the country. This trend was also seen in health statistics and marriage rates. One of the few positive things to come out of the country was the first of the first formation of a new government agency. After the Ankosh earthquake, the National Institute for Civil

Defense was established by the Peruvian government as a direct result of the earthquake to help reduce the impact of natural disasters in areas with seismic activity. The system works by using a risk management approach. The implementation of the program within Peru has helped the country prevent further disasters of this magnitude from happening again. The Ankosh earthquake remains one of most devastating in all of history. It killed tens of thousands of people, destroyed large amounts of property, and exposed the ineffectiveness of the Peruvian military government. And as with so many earthquakes, its deadliness didn't come from the quake itself, but rather the damage done to buildings and the massive avalanche that resulted from the collapse

of a nearby glacier. The executive producer of Everything Everywhere Daily is Charles Daniel. The associate producers are Austin Otkin and Cameron Kiefer. Research and writing for this episode was provided by Olivia Ash. My big thanks go to everyone who supports the show over on Patreon. Your support helps make this podcast possible. And I also want to remind everyone about the community groups on Facebook and Discord. This is where everything happens that's outside of the show. As always, if you leave a review on any major podcast app or in the above community groups,

you two can have it read on the show.