Researchers Date the Historic Ilopango Eruption That Destroyed Part of the Maya Civilization

An international research team has established the precise date of a major volcanic eruption that laid waste to the Maya civilization some 1590 years ago.

Previous studies have identified the existence of a major volcanic eruption known as the Terra Blanca Joven, which literally translates to "Young White Earth."

A research team led by Victoria Smith, associate professor from the University of Oxford, and includes Dario Pedrazzi from Geosciences Barcelona - CSIC, have tested samples to establish the precise year of the TBJ Ilopango eruption.

Analyzing Samples from Greenland and TBJ Ash Deposits

To pinpoint the date of the Ilopango eruption that razed its surrounding Maya civilization communities, scientists analyzed the ash later found in an ice core record recovered in Greenland. This sample is located more than 7,000 kilometers (more than 4,300 miles) from the Ilopango location.

Calculations patterned after a 3D tephra dispersal model showed that the magma dispersed by the volcano must be somewhere between 37 to 82 cubic kilometers of debris, flung to distant places by an eruption column about 45 kilometers high.

These values show, to put in perspective, that the Ilopango eruption exceeds that Mount Pinatubo eruption of 1991, which launched ash clouds that traveled the world more than once.

Another sample, a slightly charred tree that was found in pyroclastic-flow deposits of the TBJ Ilopango explosion, located at about 25 kilometers north-northwest from Ilopango. The Mahogany was intact, allowing the researchers to observe its growth rings - 37 at maximum.

They were able to place the year of the historic eruption as 431 CE.

To estimate the age of the Mahogany sample, researchers used a state-of-the-art Micadas Accelerator Mass Spectrometer, with the equipment available at the University of Groningen in The Netherlands.

Understanding the Volcanic Activity that Razed the Maya Civilization

Pedrazzi explained that the latest study follows previous works, and thanks to the analysis of ash deposits in El Salvador, they were able to surmise that the eruption "reached its climax with a series of pyroclastic flows linked [to] a caldera collapse."

At the time of the TBJ Ilopango explosion, it deposited ash over what is now known as El Salvador, back when the Maya still inhabited the place. It immediately rendered all areas within at least an 80-kilometer radius around the Ilopango uninhabitable for the following decades.

It was also believed to be the cause of a cold decade, a meteorological anomaly, that is centered at 540 CE. However, this is in conflict with archaeological evidence (pottery) which suggests a period closer to the Early Classic period, coinciding with the time frame when the Maya civilization started expansion across the Central Americas.

The remains of this volcano are now known as Lake Ilopango, the crater lake after the caldera collapsed. It is a 72 square kilometer lake located some 10 kilometers from San Salvador City, El Salvador's capital.

Ilopango's only recorded eruption, which occurred from December 31, 1879, to March 26, 1880, was responsible for the formation of small islands now known as Islas Quemadas.

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