Bristlecone Cave Climate Studies

This article was originally published in The Midden – Great Basin National Park: Vol. 16, No. 2, Winter 2016.

By Gretchen Baker, Ecologist

In August 2016, three dataloggers were downloaded in the difficult-to-access Bristlecone Cave, located above 10,000 feet. These dataloggers had been programmed in 2011 to record temperatures every two hours and were placed in various locations: the top, about 10 feet below the entrance; Pendulum Pit, about 90 feet down; and the Side Passage, about 80 feet down.

Figure 1. Temperature data in Bristlecone Cave. The solid blue line indicates five years of data from Side Passage in the cave; the dotted red line shows three years of data from Pendulum Pit, and the dashed green line shows data near the entrance.

Two dataloggers recorded temperature data for just over three years, while the third datalogger, the one in the Side Passage, recorded temperature data for five years (Figure 1). The data shows the middle part of the cave has annual temperature fluctuations, varying from about -2°C to 4.5°C in the Side Passage and Pendulum Pit. The datalogger closer to the entrance recorded much larger temperature changes, from -8°C to 14°C. The lag in the temperature warming in Pendulum Pit as compared to the Side Passage may be due to snow collecting in the pit. More data analysis is underway.

Four new climate dataloggers were installed in the cave and one in the bristlecone pine at the entrance. About 17 caves in the park now have dataloggers in them to help understand the temperature and humidity of these caves at different elevations.