Long-term consequences of climate change
Satellite imagery from NASA will help CSU Geographer Stephen J. Leisz and colleague Christopher T. Fisher examine the long-term consequences of climate change on ancient societies in Mexico and model long-term human and environment interaction in the Lake Pátzcuaro Basin in Michoacán, Mexico.
The high resolution ALOS PRISM satellite data provided to the team through the NASA grant will be integrated with ongoing archaeological and paleoenvironmental investigations to examine relationships between climatic fluctuation, landscape development, land degradation and the formation of complex societies in the west central highlands of Mexico, as part of the Legacies of Resilience: The Lake Pátzcuaro Basin Archaeological Project.
Remote sensing data
The project uses remote sensing data to better model the ancient landscape in ways not possible with data otherwise available. It is expected that the development of high-resolution, large-area, elevation models from the satellite data will represent an important archaeological tool for the research team.
“This research will allow us to create and test high spatial resolution models of linked human and environmental development and collapse over long periods of time that will in turn help current and future conservation efforts throughout Latin America,” said Leisz.
New and innovative technique
Researchers will examine the impact of the Medieval climatic anomaly (A.D. 950-1250) and the subsequent ‘Little Ice Age’ on Central Mexico.
By integrating ALOS PRISM satellite data into their research, Leisz and Fisher are offering a new and innovative technique, with potential for use by other scientists.
“The Lake Pátzcuaro Basin is an important example of coupled human and environmental change,” said Fisher, director of the Legacies project.
“A key aspect of the Legacies project is to create explanatory models to help explain changes in ancient lake level, distribution of agricultural lands and the location of ancient settlements. We want to see how people in the past responded to climate change as examples that can help modern policy.”
Fisher and Leisz will specifically look at the impact of the Medieval climatic anomaly (A.D. 950-1250) and the subsequent ‘Little Ice Age’ on Central Mexico.
“For the Lake Pátzcuaro Basin, the Medieval climatic anomaly likely lowered lake levels and increased the agrarian potential of the region, while the opposite may have occurred during the Little Ice Age,” said Fisher. “This is the opposite impact expected by many researchers.”
How ancient peoples modified their landscape
“Through the NASA-supported research we hope to better understand how ancient peoples modified their landscape to mitigate the impact of climatic fluctuation,” Leisz said. “As societies become larger, they have access to increasing amounts of labor that they often invest in the landscape to mitigate environmental change.”
One important outcome of the project will be a better understanding of the timing, form, and function of intensive agricultural features such as terraces that are found throughout the Lake Pátzcuaro Basin.
“Ultimately we hope to focus on environmental change as a long-term process rather then a trigger for social complexity,” said Fisher.
Collect ground reference data in conjunction with satellite
CSU graduate student Jason Bush surveying with Trimble equipment in Michoacán, Mexico.
Fisher and Leisz begin field work on the two-year, $155,591 grant in summer 2010. The researchers will use TrimbleRecon rugged handheld computers as well as the GeoXH and GeoXT GPS receivers, to accurately map every cultural feature they encounter as well as collect ground reference data that will be used in conjunction with the satellite imagery to create high-resolution elevation models of the Lake Pátzcuaro Basin.
Fisher and his team recently discovered the ruins of an ancient urban center in the heart of the Purépecha Empire in Lake Pátzcuaro Basin, located in the central Mexican state of Michoacán.
Multidisciplinary research project
The multidisciplinary Legacies of Resilience: The Lake Pátzcuaro Basin Archaeological Project includes archaeologists, geologists and geographers from the United States and Mexico. They explore prehistoric sites to better understand the development of prehistoric societies and relationships between humans and climate change.
Fisher is a fellow with CSU’s School of Global Environmental Sustainability.
Contact: Kimberly Sorensen
Phone: (970) 491-0757
Project Uacusecha is an on-going archaeological exploration of the Zacapu Basin malpaís. Led by French archaeologist Grégory Pereira and team, Project Uacusecha aims to understand social organization, urbanism, and economic dynamics in the region prior to and during Purépecha State formation. Project Uacusecha involves settlement pattern survey and excavation that builds on long-term research by the French team in the region. The setting (malpaís) and archaeology is very similar to that encountered by the Legacies of Resilience Project (LORE-LPB) and we are excited by the results of their 2010 season.
In a recent article for the Spring 2010 issue of American Archaeology, the magazine sponsored by the Archaeological Conservancy, writer Kristen Ohlson (“Stalking the Divine“, “Kabul Beauty School“) interviews several contributors from the book I co-edited with Brett Hill and Gary Feinman, “The Archaeology of Environmental Change: Socionatural Legacies of Degradation and Resilience“.
Charles Redman and Margaret Nelson (Arizona State University) discuss the interaction between climatic variation and the development of the Southwestern Hohokam and Mimbres cultures. Vernon Scarborough (University of Cincinnati) draws from his research in the Mesoamerican lowlands to explore modern lessons from the Classic period (A.D. 300-900) Maya collapse. I outline the Lake Pátzcuaro case study emphasizing the value of long-term records and inverse relationship between population density and land degradation. And Brett Hill (Hendrix College) provides a great quote “The whole point of our book is that environmental degradation is not something that happens to people.” “It’s a process involving the relationship between people and their environment, and between people and other people”
Ohlson emphasizes many of the key points of our book – the value of long-term records for modern conservation, past lessons for modern policy, the danger of homogeneity, and unintended consequences. The article closes with a comment from me “I’m trained to look at dead people’s garbage, not talk to live people” Fisher says, “this underscores the point that we need to work with cultural anthropologists and other scientists who are better trained to help us deliver our message.” And a more nuanced message from Charles Redman “I think archaeologists always know we can’t answer questions all on our own,” says Redman. “We’re always pulling in other people to help us figure out what we’ve found. It’s an organizational attitude that’s particularly valuable for these deliberations.” So, can archaeology save the environment? Yes, and more.