Archaeologists have been wondering how the drought affected the Mayan collapse. The answer was in a remote cave

The sayinger says that the devil is hidden in the details. Often, when we talk about archeology, key clues too. Archaeologists who investigate the collapse of The Mayan civilization. For years experts wonder if that decline was motivated by changes in commercial routes, wars or climatic factors, such as droughts, a theory that has gained weight over the last years. What historians did not know is to what extent the Maya endured the shortage of rain between the ninth and 10th centuries.

Now we finally know.

And all thanks to A stalagmit Lost in a remote cave of Yucatan.

What happened? That archaeologists have just achieved a valuable clue to better know the history of Mayan civilization. And not any period.

What they have discovered is a fact that sheds light on one of their most fascinating chapters, The collapse of the classical period, a phase that extended Between the IX and X Centuries From our era and that he saw how the flourishing Mayan civilization fell into decline and the twilight of large cities arrived. During that stage the southern limestone settlements were abandoned and civilization moved northlosing part of its influence at a political and economic level.

What have you found out? That this stage was marked by droughts. To be more precise, archaeologists have found out that between 871 and 1021 of our era they happened Eight long droughts In the Yucatan Peninsula, periods of water shortage that with all probability influenced the population. Not all of them lasted the same, but experts estimate that each of those episodes of agostation lasted at least three years, although there was one in particular that extended 13.

Let us talk about extreme droughts It does not mean that it did not rain. With that term archaeologists refer to periods of at least three consecutive years during which the dry station lasted more months than usual or even in which one cannot talk about wet season as such. The experts They recognize That 13 years under these conditions, even with the water management techniques developed by the Maya, leads to “a great impact for society.”

Why is it important? Because as the authors of the investigation recognize in An article Posted a few days ago in the magazine Science Advancesthat prolonged drought chain could play a key role in the history of the Maya, “contributing to the collapse of classical civilization.”

“This period of Mayan history has fascinated us for centuries”, Recognize Dr. Daniel H. James, author of the study. “Multiple theories have emerged about the cause of collapse, such as changes in commercial routes, wars or severe droughts, based on the archaeological evidence left by the Maya. But in recent decades we have begun to learn a lot about what happened to the Maya and why, mixing archaeological data with quantifiable climate evidence.”

Is it something new? Yes. And no. It is not the first time that archaeologists explore the impact that droughts had on the decline of classical Mayan civilization. Over the last years they have already reached more or less similar conclusions thanks to sediment study collected at the bottom of the Chichankanab lagoon or of Stalactite samples Obtained in a cave in southern Belize, clues that pointed to the role played by climate oscillations in The Mayan collapse.

The new data obtained by James and their colleagues also fit other signals, as with the dates left by the Maya themselves in their monuments or records in the popular Chinchén Itzá. There, in one of the great settlement of the Yucatan, the inscriptions of dates are mysteriously faded just during the periods in which we now know that there were severe droughts.

“It does not mean that the Maya left Chichen Itzá these periods, but it is likely that they had more urgent things than to worry about building monuments, as if the crops on which they depended would be successful or not.”

So … why is it important? Although It is not the first time that archaeologists point to the effect of droughts in the Mayan collapse the new study published in Science It is important for several reasons. First, for your approach. Second, for its precision. In this case, researchers have departed from an especially valuable track: the stalagmites located in a Yucatan cave.

Thanks to the dating and analysis of the oxygen isotope layers that contain these calcareous rocks, formed on the ground with the water that drips in the cave, experts have been able to obtain “very detailed information” on the climate of the terminal classic period. “Previous studies have measured the isotopes contained in lake sediments to determine the severity of drought, but do not contain enough detail to accurately find out the climatic conditions in a specific year and location,” They clarify From Cambridge.

Unlike what happens with the sediments collected from the bottom of the lakes, “excellent to obtain a global vision,” says James, the stalagmites offer a variety of concise data. “They allow us to access more precise details that we were missing,” Write down the expertwho now acts as a researcher at the University College in London. According to the team, this has been the first time that archaeologists have been able to isolate information about the rains of humid and dry stations individually, obtaining the details of each one.

How precise are they? Its authors say so. So far the stalagmites had provided data on rainfall annual measures during the classical terminal periodbut that information did not allow scholars to go down to detail. How much did it rain exactly in humid stations and dry? Thanks to the Yucatan stalagmite analyzed by the experts, which contains relatively thick annual layers, of about a millimeter, the experts have been able to analyze oxygen isotopes of each stage, an indicator of the drought.

“Knowing the average annual rainfall does not reveal as much as knowing how every rainy season was”, Dr. James points out. “Isolate the rainy season allows us to precisely track the duration of drought during the rainy season, which is what to determine in turn the success or failure of crops.”

It was that succession of layers of the stalagmite that revealed to the team that between 871 and 1021 eight droughts of at least three years had happened and that the worst of all lasted 13 years. Now experts believe that these valuable tracks can yield new data, such as “the frequency and severity” of tropical storms.

Images | Álex Azabache (UNSPLASH), Hoyt Roberson (UNSPLASH) and Max Böhme (UNSPLASH)

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