A RADIO-TELEMETERED TEMPERATURE SENSOR NETWORK TO MONITOR HYDROTHERMAL ACTIVITY AT YELLOWSTONE NATIONAL PARK'S NORRIS GEYSER BASIN

During June 2010, a radio-telemetered temperature sensor network was deployed at the Norris Geyser Basin of Yellowstone National Park. Norris is the most dynamic thermal area at Yellowstone and displays a variety of transient thermal phenomena that are thought to relate to hydrologic, volcanic and tectonic activity. The sensor network can provide realtime updates on temperature variations due to anomalous hydrothermal discharges or subsurface fluid migration. Ten loggers are distributed in the basin and are programmed to measure temperature every two minutes by means of 5-m-long teflon-coated thermistors. Each logger consists of a waterproof case containing an M5 logger (made by Marathon Products, Inc.^®) with internal memory, lithium D-cell batteries and a 900 MHz, 1-W-radio. Stub and panel antennas are oriented to optimize signal strength. The loggers communicate with a 0.61-m-long base-station antenna located 10-m up a tree near the Norris Museum. The furthest node is 720 meters distant from the base station. Most radios are placed “line-of-sight.” A 20-m coaxial cable and lightning arrestor connects the base-station antenna to an Ethernet-radio connected to the YNP local-area network. A server located 26-km north at Mammoth Hot Springs requests data each day, and then sends it to the USGS for archiving and internet distribution. During periods of unusual hydrothermal behavior, data can be requested as needed in realtime through programmable alarms or manual uploads.

The network is designed to monitor changes from three different sub-basins at Norris (Gray Lakes, Steamboat-Echinus and Porcelain Basin), the main Tantalus Creek drainage, and five individual thermal features (Constant, Porkchop, Steamboat and Echinus Geysers, and Opalescent Spring). Nuphar Lake provides ambient temperatures controlled solely by local meteorological conditions. Soil temperature is measured near Vixen Geyser. We intend to automatically upload data and distribute it via the internet to display temperature variations at each logger over 24-hour, 7-day, and 1-month periods. This will permit land managers, scientists and the public to keep track of changes to the hydrothermal system, including geyser eruptions, periodic basin-wide disturbances, or fluid-release events that may accompany or follow seismic activity.