RAPID: Characterizing El Nino Runoff And Sedimentation In Small Drainage Basins: A Geoarchaeological Study

Harvard University, Cambridge MA

Investigators

Abstract

It is now well known by the general public that El Niños have dramatic impacts world wide yet, in many ways there is still much to learn about these events and their effects. This project will help us to better understand past El Niños so that one can better prepare for them in the future. El Niños occur when warm waters from the South Pacific travel eastwards and override the cold waters of the Humboldt Current that flows from south to north along the coast of Peru. This produces rains on the normally arid Peruvian coast and droughts in the highlands but also affects the weather in Mexico, the Caribbean, the United States, and even Western Europe. El Niño-induced weather is radically different from normal variations in these areas and usually results in severe impacts to economies and human lives. Knowing when El Niños occurred in the past, their intensities, and frequencies thus are important to help us understand El Niños in general and to learn how to avoid or mitigate their impacts. Dr. Jeffrey Quilter of Harvard University will direct a small research team to focus on a specific aspect of El Niños on the coast of Peru that will produce important data and information. In the 15th century, ancient Peruvians built earthen aqueducts in their extensive canal systems. These aqueducts cut across the mouths of side canyons in larger valleys, thus creating dams for any water flowing through them during El Niño events. Over time, sediments from El Niño events were built up behind these aqueduct-dams. While el Nino related sediments can be identified in relevant deposits it is not possible to determine rates associated with individual el Nino events. This award will permit measuring devices to be installed in areas behind multiple dams to determine sediment buildup resulting from heavy rainfall predicted to occur during the upcoming el Nino season. These deposits can then be analyzed to better understand earlier strata and the El Niños that deposited them. This work will be done in cooperation with Peruvian authorities who will monitor the events via drone technology as they happen.