Final answer:
D. Perry collected samples from a shallow firn core in Southern Peru to analyze past atmospheric CO₂ concentrations and temperatures, using methods like those seen in ice and sediment core research for climate history and extraterrestrial studies.
Step-by-step explanation:
In recent research expeditions to the Cordillera Vilcanta in Southern Peru, D. Perry dug a 2-meter-deep snow pit and collected samples from a shallow firn core to analyze past climatic conditions. The analysis likely involved examining indicators such as trace elements, stable isotopes, and perhaps organic compounds to reconstruct historical atmospheric CO₂ concentrations and regional temperatures.
These methods are similar to those used in geology and planetary science, where ice cores are studied to understand the Earth's climate history or to search for water and carbon compounds in extraterrestrial environments as seen in the MESSENGER and Phoenix spacecraft missions. For example, ice cores from the Russian Vostok station in East Antarctica provided valuable data on past atmospheric conditions by measuring trapped CO₂ and deuterium levels. Similarly, sediment cores, like those taken from the Wilkes Subglacial Basin, are analyzed for geochemical signals such as neodymium (Nd) and strontium (Sr) to trace their origins.