Field of Science

The End of the Mayan World

According to the popcorn-movie "2012" (2009) the end of the world will come due increased solar activity that will overheat earth and cause catastrophic volcanic and tectonic storms on December 21, 2012. This premise is so dumb that even NASA declared "2012" as the most "absurd science-fiction movie" of all times, not only because the science is so bad, but the movie exploits also the fear mongering story of the supposed end of the Mayan calendar, first proposed by artist and author José Argüelles in 1987. Almost all of the supposed end of the world tale is nonsense, the various proposed mechanism to explain the destruction of the planet, like solar eruptions, pole shift or the impact of an invisible planet, are unrealistic, as it is unrealistic to claim that the end of a arbitrary time period has any significance for earth.

Fig.1. The goddess Chakchell, with her terrifying snake headdress, is flooding earth with the waters coming from the jar of the gods. She is helped in this task by the dark god of the underworld, with an owl as symbol of his power, and the divine crocodile - even the holy hieroglyphs are crying and the world will soon drown (after the "Codex Dresdensis", ca. 1200-1250, plate 47 "The flood").

However in the last years the Maya Civilization arouse the interest not only of crackpots, but also serious historians and even climate scientists. This ancient society possessed advanced knowledge of astronomy, mathematics and architecture, but 1.200 years ago (750-950 A.D.) the various city-states on the Yucatan peninsula suffered a sudden collapse. Various hypotheses tried to explain this demise: internal warfare, foreign invasions, diseases, overpopulation in combination with environmental degradation and climate change.
The Yucatan peninsula is characterized by a heterogenic spatial distribution of precipitation and seasonal droughts, especially during the beginning of the year (January- May). The climate is influenced by the position of the Intertropical Convergence Zone (ITCZ), wind systems that shift position due the seasons and bring moisture to the land. The Maya had to deal with these variations and in response build large artificial reservoirs. The limestone of the Yucatan peninsula is highly permeable and the groundwater is almost inaccessible, if not by naturally occurring caves or cenotes, and there are virtually no rivers.
It was in these cenotes that geologists of the University of Florida collected sediment cores and discovered in the isotope variations of shells a pronounced drought period between 800 and 1000 A.D., coincident with the collapse of Classic Maya civilization. A even more detailed reconstruction of the climate of the region was possibly by the research done on sediments from the Cariaco Basin, a basin with limited deep water mixing and anoxic conditions on the ground (and therefore perfect sedimentation conditions) offshore Venezuela. Depending from the position of the ITCZ fossil-rich or clastic-rich layers are deposited, so by studying and counting these layers the former variation of the ITCZ and the amount of precipitation can be estimated.
Also this record shows a climate shift and cyclic multi-year droughts from 910 to 760 A.D.

According to the proposed scenario a population at the margin of environmental sustainability experienced repeated droughts and a demise of agricultural production. The various city-states, chronically involved in wars for power and sacrifice victims, consumed the last reserves in a desperate struggle for survive.

However like in the case of Easter Island considering both evidence from natural sciences and historical and cultural circumstances the scenario could become more complicated. The Mayan Civilization was characterized by religious violence and war was less aimed to destroy the enemy than to catch (and sacrifice) the political elite. This society had also survived previous droughts or phases of increased soil erosion, when in A.D. 550-830 the population reached high densities. The power became concentrated in few city-states, which struggled for power and replaced small military expeditions with great wars. The crumbling central government could no longer guarantee the safety of peasants, when the society was further weakened by climate changes.
In the end the city-states were replaced by a most decentralized kind of society, whit the descendants still living today.

Bibliography:

ANSELMETTI, F.S.; HODELL, D.A.; ARIZTEGUI, D.; BRENNER, M. & ROSENMEIER, M.F. (2007): Quantification of soil erosion rates related to ancient Maya deforestation. Geology Vol. 35(10): 915-918
GILL, R.B. (2000): The Great Maya Droughts - Water, Life, and Death. Univ. New Mexico Press: 464
PETERON, L.C. & HAUG, G.H. (2005): Climate and the Collapse of Maya Civilization. American Scientist, Vol. 93: 322-329

4 comments:

  1. They were taking a lot of strange hallucinogens and deliriants as well. That is bound to make it difficult to cope with change, daily life and remembering where you live.

    ReplyDelete
  2. What about the poles switching? I've read that the North & South Poles switch every 200,000 years or so and that scientists are not sure what may happen as a result. Any comments?

    ReplyDelete
  3. It's true. The Mayans were deathly worried about waking up one morning with wonky compasses. Good thing they warned us.

    ReplyDelete
  4. Wikipedia summarizes it well:

    "Most estimates for the duration of a polarity transition are between 1,000 and 10,000 years"

    "The magnetic field may not vanish completely, with many poles forming chaotically in different places during reversal, until it stabilizes again"

    "Statistical analysis shows no evidence for a correlation between reversals and extinctions"

    http://en.wikipedia.org/wiki/Geomagnetic_reversal

    Chris Rowan discuss the questions in much more detail:

    http://all-geo.org/highlyallochthonous/2009/02/is-the-earths-magnetic-field-about-to-flip/

    ReplyDelete

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