natural disasters: The Americas that which destroyed Pompeii in 79 c.e.) or even the counterpart of the vague and flimsy allusions to the Thíra eruption discerned in Egyptian texts, the Old Testament, and the writings of Plato In the absence of written records, we have very little evidence for the cultural impact of natural disasters on the indigenous peoples of North America for this period The most significant and widespread environmental change affecting ancient North American culture history was certainly the end of the last ice age 10,000–12,000 years ago and the subsequent extinction of many species of large mammals, such as mammoths, mastodons, giant sloths, and wild horses Since these animals provided food sources for the earliest Native American hunters, their demise forced a shift in lifestyle away from highly mobile big-game hunting to a less nomadic hunting and gathering way of life What we have in Mesoamerica is the archaeological and geological evidence of massive volcanic eruptions that buried settlements, adversely affected agriculture, and occasioned migration and population shifts While polities in the immediate vicinity of the disasters collapsed and were abandoned because of these events, other political centers may have benefited by the influx of migrants and a gain in religious prestige In Peru climate change and catastrophic weather events on the coast, related to the phenomenon of El Niño, may have led to the collapse of ritual centers and their associated ideology, paving the way for the spread of a new religious cult originating at Chavín de Huántar in the highlands In the basin of Mexico the eruption of the volcano Xitli devastated the city of Cuicuilco during the Late Formative to Early Classic phases of cultural development Precise dating of this geological event is still a matter of dispute, but it occurred over about a decade sometime between 400 b.c.e and 400 c.e., perhaps close to 50 b.c.e Cuicuilco, situated in what is now the southern outskirts of Mexico City, was first blanketed with ash and then buried under up to 33 feet of lava The resultant volcanic layer covers a 30-square-mile area and has made excavation of the site difficult, forcing early-20th-century diggers to resort to explosives to clear buried structures It is possible that because of earlier volcanic episodes, the site had been wholly or partly abandoned prior to the main eruption Some scholars speculate that both the displaced population and the city’s possible loss of religious prestige in the face of what would have been interpreted as the wrath of the gods contributed to the growth and influence of the city of Teotihuacán in the northern part of the basin Ironically—or perhaps appropriately—stone sculptures retrieved from beneath the lava flow indicate that a deity in the form of an old man, corresponding to the later Aztec fire god, was among the chief gods of Cuicuilco In present-day El Salvador extensive ashfall from an eruption of the volcano Ilopango around the turn of the fourth century c.e seems to have rendered local agricultural 783 land unusable and precipitated an exodus from the area As in the case of Cuicuilco, a rising city may have benefited from this calamity In this instance it was the Maya city-state of Copán, north and east of Ilopango in western Honduras Refugees from Ilopango’s eruption, drawn by the rich lands of the Copán region, may have increased the city’s population, which in turn contributed to the city’s rising influence over the next several centuries In Peru the recurrent phenomenon of El Niño seems to have massively and negatively affected the cultural history at several junctures in the last three millennia Named in historic times for the Christ child because of its appearance around Christmas, El Niño is a warm-water current that reaches the coast of Peru every year, usually for only a few weeks The cause of this eastward-moving current is a decrease in easterly trade winds, which leads to the flow of warm water from the western Pacific to Peru Every three to seven years a major El Niño event occurs in which the warm current affects the Peruvian coast for longer than usual—up to months—creating havoc with the coastal environment Cool-water marine life dies off in the warmer temperatures, and torrential rains create extensive flooding onshore Some of these events are of truly catastrophic magnitude Some evidence suggests that major events of this kind beset the coast of Peru around 500 b.c.e., killing the cold-water fish that were a staple of the local economy and destroying desert irrigation systems through flooding These disasters may have led to the decline of coastal ceremonial centers (though some archaeologists think they were already in decline owing to other factors) and with them the prestige of the cults they supported This change may have left the area receptive to new religious ideologies emanating from the highland site of Chavín de Huántar The new beliefs are reflected in the adoption of highland deity images and other motifs in coastal ceramics and textiles Interestingly, an increase in social stratification and centralized political power may have occurred in the Chavín area sometime around 400–200 b.c.e as a consequence not of floods but of drought, leading to increased competition for resources, a situation frequently conducive to the rise of strong leaders and growing differentiation of social classes See also agriculture; architecture; astronomy; building techniques and materials; ceramics and pottery; cities; climate and geography; economy; empires and dynasties; foreigners and barbarians; health and disease; hunting, fishing, and gathering; inventions; literature; nomadic and pastoral societies; migration and population movements; money and coinage; pandemics and epidemics; religion and cosmology; resistance and dissent; sacred sites; settlement patterns; slaves and slavery; social collapse and abandonment; towns and 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