Arizona Caves Hold Archive of Climate Data
In the Santa Rita Mountains southeast of Tucson, University of Arizona graduate student Sarah Truebe is looking for clues on past climates inside of caves.
A graduate of Stanford University, Truebe is a doctoral student in the University of Arizona’s Department of Geosciences, a world leader in providing data to environmental policymakers working on responses to climate change.
Speleothems are similar to trees in that they have discernible layers, or rings which can be studied to learn about their creation over time. To collect the data, she extracts core samples from stalactites and then takes them back to the lab for analysis. The age of the core can be determined by radiocarbon dating, and how much water fell can be measured by the size of the rings.
During her more than 30 monthly visits to Cave of the Bells, a wild cave in the Coronado National Forest, she has been working specifically on deciphering the patterns of the Southwest’s past monsoon rains.
In many parts of the world the climate record only goes back 50 to 100 years. In order to build a climate model accurate enough to make predictions and form policies, a larger set of data was required. No matter how sophisticated and detailed real-time observations might be, computers can’t predict the future without long-term data to guide them.
Paleoclimatologists collect data from a number of different sources. Tree rings, coral reefs and layers in cave formations act as natural archives, holding information on precipitation, forest fire, volcanic eruptions, ocean currents and more. From this data, researchers have enough data to create a continuous climate model that goes back 9,000 years.
Arizona Caves: An underground archive of climate data [Green Valley News & Sun]