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Warm Water, Cold Water
Tracing El Niño to the Shores of Peru

Curator James Richardson at Machu Picchu.

James A. Richardson III, curator of Anthropology at Carnegie Museum of Natural History, has been digging in the sands of ancient seashores nearly all his life. Born in Massachusetts, his family has a house on Martha’s Vineyard, where as a child he would play on the beaches, and later as an archaeologist he would dig up evidence of the early inhabitants who lived on the island.

But what he will most likely be remembered for in the world of maritime archaeology took him far from the Vineyard. In the 1980s, Richardson discovered that the ancient people of the shores of Peru some 5,000 years ago left behind evidence that today reveals a lot about El Niño, the periodic storms that bring disaster to the western coast of South America and the islands of the Pacific Ocean.

For thousands of years El Niño was absent and therefore not a factor in cultural change along the Peruvian coast. But after ca. 6,000 B.P. (Before the Present), the sea level rose to near current levels and the modern coastline was formed. At this time the cold Peru (Humbold) current shifted northward from 12 degrees south latitude to 4.3 degrees south latitude. The colder Peruvian current brought with it the ocean fish and molluscan riches that soon formed the basis for the rise of the temple societies along the Peruvian coast.

The 200-meter depth contour typically
defines the outer edge of the continental shelf.
The shoreline 11,000 years ago was just inside
the current 100-meter contour.

Still, the warm ocean current returned at irregular intervals as El Niño, a counter-current. The warm waters of El Niño bring death to plankton and fish and cause severe storms in the Pacific and on the South American coast. The storms were called “the Christ Child” (El Niño) because they came with the onset of warm weather before Christmastime in the Southern Hemisphere.

Richardson’s research has traced back for thousands of years evidence of the people who lived along the changing seacoast. Their ancient debris of cooking shellfish, fish, birds, and sea mammals, testifies to the rising of the sea levels, which were 400 feet lower 25,000 years ago. Although many ancient inhabited sites along the level seashore are now underwater, in those places where the seacoast is narrow (because the continental shelf is short between the mountains and the deep ocean), the evidence of ancient human habitation can still be examined.

In 1986, Richardson and his colleague Daniel Sandweiss of the University of Maine proposed that the record of warmwater shellfish at northern Peruvian coastal sites led to the conclusion that El Niño did not begin or originate until after 5,800 years ago. Many oceanographers, geologists, and paleo-climate specialists disagreed, believing that El Niño could not be so recent a weather phenomenon. But in trying to prove the Richardson-Sandweiss theory wrong, they actually proved it was correct. They demonstrated that El Niño did not occur in the past with the frequency that it has today. There was a 3,000- to 4,000-year period of colder waters along the coast that corresponded to the rise of the Peruvian temple cultures.

The theory about El Nino’s relationship to the first Peruvian cultures was featured in the premier issue of Discovering Archaeology (January, February, 1999). Richardson’s South American research was published in his book People of the Andes. (Smithsonian Books, 1994) n

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Learn More About Machu Picchu

Free with museum admission!

Machu Picchu Lecture Series

Co-sponsored by the University of Pittsburgh, Center for Latin American Studies, and Carnegie Museum of Natural History.

October 18, 2003, 1 p.m.
Machu Picchu--Dr. Richard Burger, Yale Peabody Museum, Co-Curator of Machu Picchu: Unveiling the Mystery of the Incas.

October 18, 11:30 a.m.
In the Lecture Hall—a musical performance by Musuhallpa. Hear the music of the Andean mountain regions of Peru, Bolivia, Ecuador, Chile, and Argentina.

Other free lectures on Machu Picchu are scheduled for November 15 and December 6. See the November/ December issue for details.

Enjoy a Lecture, the Exhibit, and a Peruvian Foods Buffet at the Museum
November 8, 2003, 10:30 a.m.
CMA Theater

Join Carnegie Museum of Natural History Curator Dr. James B. Richardson III in an exploration of the Andean people and their incredible city in the clouds.

Lecture, Buffet, & Museum Admission:
Members, Students, Seniors: $23
Non-members: $25

Lecture & Museum Admission only (no Buffet):
Members, Students, Seniors: $8 Non-members: $10

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