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Note the separation between rocks in the Sacsayhuamán Archaeological Park.

Mega Earthquake Caused Major Shift in Inca Construction Methodology

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A major new scientific study revealed by Peru’s state-run news agency Andina has confirmed that construction of the ancient Inca city, Machu Picchu, located in modern day Peru, was interrupted in 1450 AD by a 'powerful earthquake’ that caused the Inca builders to design catastrophe-resistant architecture.

What Was the Strength of The Violent Earthquake?

On the other side of the world in 1450 AD Johannes Gutenburg began operating the first mechanical printing press and the mysterious Voynich manuscript was brought to completion, but in ancient Peru, the mountains shook under the force of a violent earthquake. According to an article in The Peruvian Times, researchers from the Cusco-Pata Research Project have announced that the ancient landscape was hit by “a tremor of at least magnitude 6.5” during the reign of the 9th Inca Pachacútec.

Earthquake recorded in about 1450 AD caused the separation of rocks in Machu Picchu. (Andina)

Earthquake recorded in about 1450 AD caused the separation of rocks in Machu Picchu. (Andina)

Shift in the Earth Brings Forth Shift in Construction

Evidence of the earthquake has been gathered by an international team of scientists since 2016, led by the Geological, Mining, and Metallurgical Institute (Ingemmet), and project coordinator Carlos Benavente Escobar.  Escobar told reporters, “There was already construction underway with one type of architecture under Pachacutec. Then, we believe, in the middle of that construction of Machu Picchu there was a major earthquake.” Machu Picchu was the iconic mountain top summer estate of the 9th Inca ruler (Sapa) Pachacutec.

Sample of seismic-resistant architecture (trapezoidal): Sacsayhuamán Archaeological Park. (Andina)

How Was the Damage Evident?

It was “openings between rocks and stones” which acted as clues as the scientists knew such miss-alignments were “not typical of the Incas because they employed an impeccable, perfect construction.” The earthquake damage is most prevalent in the walls of the “Temple of the Sun” at Machu Picchu where Benavente said, “Some edges of the rocks are broken, which means that in the undulation of the earth, they hit each other which caused the breaks. After that, they continued the building in a different manner to complete what would become Machu Picchu.”

In the Sacsayhuamán Archaeological Park, there is also a separation between rocks produced by an earthquake of 1450. (Andina)

In the Sacsayhuamán Archaeological Park, there is also a separation between rocks produced by an earthquake of 1450. (Andina)

How Did the Incas Change Their Construction Methods?

An article in Porta Andeana explains that “After these deformations” caused by the earthquake, Pachacútec, having seen the underlying weakness in his current construction methodology, “arranged a modern architecture and placed masonry to repair the damage caused by the earthquake.” And the scientists also noted “Architectural change in the [agricultural] terraces.”

After the quake, the Incas began building in what is being described as “a more rustic cellular architecture and continued to develop and perfect seismic-resistant trapezoidal structures, with giant stone blocks at the base with narrower upper walls.” Benavente concluded that “They knew how to coexist with diverse geologic dangers, like earthquakes, landslides, and avalanches.”

Sample of cellular architecture: Piquillacta Archaeological Complex. (Andina)

Sample of cellular architecture: Piquillacta Archaeological Complex. (Andina)

How Can the Study of the Quake that Changed Inca Architecture Help Us Today?

Aiming to establish the geological origins of the earthquake that had such an impact on the Inca Empire, Benavente said “We are calibrating the last 14 radiocarbon ages to define what failure caused the earthquake, for the moment, it is suspected that it was the one in Tambomachay, located four kilometers from the Historic Center of Cusco.” “There is no doubt,” he says, “that the strong earthquake also caused the deformation of the walls of Sacsayhuamán, Tipón, and Tambomachay.”

Fieldwork at the Choquepuquio Archaeological Center. (Andina)

Fieldwork at the Choquepuquio Archaeological Center. (Andina)

“For the first time in history, the techniques of paleoseismology, archaeo-seismology, and active tectonics have been combined in a study of this nature,” Benavente said. And he thinks it “necessary to help current-day planners analyze the seismic hazards of the Tambomachay and Pachatusan fault lines for the Cusco region.”

Separation of rocks in Machu Picchu due to an earthquake of at least magnitude 6.5, registered in approximately 1450 AD. (Andina)

Separation of rocks in Machu Picchu due to an earthquake of at least magnitude 6.5, registered in approximately 1450 AD. (Andina)

What Has the Research Discovered?

In July this year Dr. Ken Tokeshi from Western Sydney University published a research paper, Earthquake risk to Inca's historical constructions in Machupicchu, presenting his “seismic risk analysis of the heritage structures at Machupicchu, identifying of the probable mode of failure of the structures concerned.” Like in this latest study, Dr. Tokeshi studied the “Results of the microtremor measurements to estimate the dynamic characteristics of the Inca stone structures.”

How Was the Affected Structure Used?

While it is clear that Cuzco was the ancient capital city of the Inca Empire, the function of the structure at the suspected heart of the earthquake, ‘Tambomachay,’ remains something of a mystery. Consisting of elaborate stone-built canals and waterfalls running through the rock terraces, some archaeologists believe it might have been a military outpost guarding the primary approaches to Cusco, but others think it was a spa retreat for the social, political, and religious elite from Cuzco.

Tesista Lorena Rosell in the Sacsayhuamán Archaeological Park. (Andina)

Top Image: Note the separation between rocks in the Sacsayhuamán Archaeological Park. Source: (Andina)

By Ashley Cowie



Gary Moran's picture

Thanks,, Iron. I’m a regular follower of those two. Lots of interesting info to make one think about what really happened in antiquity, and what has not been included or allowed in the little bits we are taught. 

Have a look at the UnchartedX Youtube channel if you are not already familiar with it. The guy who runs it is trying to find answers to the conundrums of how the walls were built and many other things in the ancient world and he does not subscribe to the theories of conventional archaeology either. BrightInsight is another interesting channel. And if you want to frighten the life out of yourself have a look at the Cataclysm playlist on the SuspiciousObservers channel, which is concerned with the hard science governing the cycles of happenings within the Solar system and our galaxy.

"A nation can survive its fools and and even the ambitious but it cannot survive treason from within. An enemy at the gates is less formidable..."
- Cicero, greatest orator of ancient Rome

Gary Moran's picture

It’s bewildering to me how any conscious educated mind can truly believe that the megalithic construction could have been the work of the Incas. Natives said they (and their ancestors) did not build those walls. They are so obviously different, I don’t see how anyone could think they did.  Too many times authorities are reluctant (or afraid?)  to say “we don’t know.” 

Inca construction may be the official line, but it seems to me very few people are buying that, and the four comments above all echo that opinion. Add me to the list.


Nope. Seriously, the megalithic work is WAY MORE advanced and earthquake resistant than those small rubble stones which are dumped between the big blocks.

Why is it so hard for archaeologists to acknowledge their major mistake in this?

Everywhere around the world we are finding more and more evidence that we were preceeded by a civilization which were able to construct buildings with HUGE stones. Something we cannot do even now with all our 'modern' tech.

Or do you really think that the Romans actually build the base of Baalbek?
Roman architecture is present, but, like Machu Pichu, the architecture of the civilizations we ascribe the buildings to are found ON TOP of already existing architecture which clearly show a WAY different method of building.

All those ancient civilizations (Ancient Egypt, Greece, Romans, Inca, etc) weren't responsible for the many megalithic buildings we find around the globe. It's simply impossible.

The Inca architecture (the small stones which seems dumped in place with a bit of puzzling to make it fit a bit better) is not able to withstand an earthquake with a magnitude big enough to displace the megalithic stones. If an earthquake with that magnitude hit Machu Pichu, the only stuff we would have been able to find would be those megalithic stones. All the shoddy, small-stone architecture would have crumbled all the way back to the base.

The megalithic stone work was almost certainly done by a culture that preceded the Inca. You don't go from tightly fit enormous stones to rubble-mud construction and call it an "improvement" in technique. Absurd.


ashley cowie's picture


Ashley is a Scottish historian, author, and documentary filmmaker presenting original perspectives on historical problems in accessible and exciting ways.

He was raised in Wick, a small fishing village in the county of Caithness on the north east coast of... Read More

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