( CNN ) To scuba divers and tourists , Belize 's famous `` Blue Hole '' underwater cave is a wonder , one of the `` 10 most amazing places on Earth , '' according to the Discovery Channel . To scientists , it 's something more : evidence of the drought that is suspected to have led to the demise of the Mayan civilization . New research reinforces that theory , Rice University Earth scientist Andre Droxler told LiveScience . The team drilled cores from the Blue Hole sinkhole and a nearby lagoon . They found that the ratio of titanium to aluminum changed in the ninth and 10th centuries , a period when the Mayan civilization in the Yucatan Peninsula went into decline . More titanium means that heavier rains were affecting the region , since the runoff from the area 's volcanic rock is rich in the element . But from about A.D. 800 to 1000 , the ratio between the two elements was much smaller , indicating that there was much less rainfall . `` When you have major droughts , you start to get famines and unrest , '' Droxler said . The Mayan civilization , noted for its advances in astronomy and agriculture ( not to mention that calendar system that some believed prophesied world devastation on December 21 , 2012 ) , dominated the Yucatan in the first half of the first millennium A.D . But by 900 , most of the civilization 's cities , located in present-day Guatemala , El Salvador , Honduras and southern Mexico , had been abandoned . The question of why this happened has tantalized scientists and historians for decades . The drought theory is n't new , but the findings of Droxler and his colleagues buttress other studies . In 2012 , samples from a 2,000-year-old stalagmite also showed that drought had afflicted the region in the latter half of the first millennium A.D. `` The main finding was that a prolonged drought contributed to the collapse of Classic Mayan civilization , '' environmental archaeologist Douglas Kennett told LiveScience two years ago . Droxler and his colleagues published their findings in Scientific Reports .
Investigation of Belize 's `` Blue Hole '' indicates drought did in Mayan civilization . Comment: `` When you have major droughts , you start to get famines and unrest , '' says researcher .