El Malpais National Monument was established for resources associated with ancient lava flows in west-central New Mexico. Artifacts of Zuni and Acoma nations dating from AD 800s to 1200s are located at El Malpais, including a Chaco-style great house, a great kiva, smaller pueblos, field houses, prehistoric reservoirs, and petrogylphs. A number of archaeological sites reside in El Malpais’ lava tubes, which can have annual temperatures below freezing and hold ice year-round(Bauman and Kendrick, 17).
A particular ice tube at El Malpais which has lost its ice is the Rusty Barrel Ice Cave, named after the remnants of a wooden barrel that mark its entrance. The cave also contains a ceramic artifact assemblage from the late Pueblo II period (AD 1050-1150); characteristics of this assemblage and associated charcoal and burned wood indicate that people were visiting the cave to melt ice and fill jars with water (Bauman and Kendrick, 18).
Rusty Barrel Ice Cave has been under observation for many years, allowing managers to track changes in its ice levels. Photos from the 1980s show the cave still full of ice. Since then, annual average temperatures above freezing and increased precipitation have melted all the ice except for what remains in the lowest and coldest part of the cave (18). Today, precipitation in the region continues to affect ice levels in El Malpais lava tubes (Bauman, personal communication).
More information on Southwest historic and projected climates available here .
1. Baumann, Steve, email to the author, September, 2013.
2. Baumann, Steve and James W. Kendrick. “Climate Change and the Deterioration of Cultural Resources: El Morro and El Malpais National Monuments in West-Central New Mexico.” Vanishing Treasures Fiscal Year 2010 Year-End Report, (2010): 17-21.
3. United States Global Change Research Program (USGCRP). “Regional Climate Trends and Scenarios: The Southwest U.S.” 2013 http://scenarios.globalchange.gov/sites/default/files/NCA-SW_Regional_Scenario_Summary_20130517_banner.pdf.