DESIGNING, BUILDING, AND OPERATING A LONG-TERM INSTRUMENTATION NETWORK IN THE OMEGA CAVE SYSTEM, VA, USA: RESULTS AFTER THE FIRST YEAR

Many caves around the world have had instrumentation systems installed in them. Most of these systems are designed to support specific research questions by collecting data for a time period that is defined by the funding and/or lifetime of the instruments. Few sites exist where an entire cave system has been instrumented with the following objectives in mind: 1) collect high frequency long-term data (decades), 2) install an instrument network that requires minimal maintenance after installation (one-year visits, ideally), and 3) build a robust time-series data-set that can be used as a foundation for additional studies and instrumentation in the future. In 2014 the Cave Conservancy Foundation funded a small grant for instrumentation and in support of these goals.

In 2014 and 2015 we designed and built 7 concrete and stainless steel weirs in Omega Cave; four in the major tributaries and three at main stem sites. At each site, water temperature, discharge, and specific conductance are recorded at 15 minute intervals. Air temperature and relative humidity are measured every 30 minutes. Inside and outside the two entrances, temperature, relative humidity, and barometric pressure are measured.

The Omega Cave System instrumentation network has one more important goal: after a reasonable period of time for use in our own research, all data and metadata will be hosted online and openly accessible for any other researcher to use. The reasons for this are to create a permanent and accessible data repository, and to encourage and facilitate research and collaborations that might otherwise not happen. We hope this sets an example and encourage similar sharing of cave monitoring data by others around the world.

Initially, these data will support modelling efforts to understand how the system behaves hydrologically, biologically, and atmospherically, and will later support designed experiments and specific hypothesis testing in hydrologic, geochemical, and speleogenetic research.

Our first year of data revealed both successes and technical problems. However, the problems are relatively minor and the first year can be considered a success overall.