The Lake Chelan Research Institute, Oregon State University, and Chelan County Natural Resources announce the installation of temperature sensing fiber optic cables in Lake Chelan. The cables, installed September 26, 2017, are a total length of 3.8 km (2.4 miles) and will measure temperature every meter along their length at 15‐minute intervals.
The temperature data will enable detection of both overturn of the lake in the winter and the rocking back and forth of the deep, cold water in Lake Chelan during the summer months. Movement of the deep, cold water is known as the internal seiche of the lake and is a world class feature of Lake Chelan that has been studied only once during the summer of 1987.
In 1987, the internal seiche was so large that the deep, cold water displaced the warm surface water completely at either end of the Lucerne Basin as the deeper water rocked back and forth every other day.
Results of the study will be crucial to understanding Lake Chelan’s water quality measurements and optimal sampling times in Lake Chelan since the deeper water typically has lower nutrients than the warmer, shallow water.
Understanding the internal seiche will also help researchers to know the best days for swimming in Lake Chelan and to predict lake currents at the narrows. The cables will remain in place for at least a year, providing ongoing lake temperature data.
Surface buoys mark the location of the submerged up leg of the fiber optic cable. There is a smaller white buoy next to the main buoy. The white buoy supports near surface temperature sensors at depths not covered by the fiber optic cable. Fisherman, commercial lake users, recreational boaters are asked to avoid these buoys and the submerged fiber optic cables.
This map shows the location of the two surface marker buoys (at the yellow and orange pins). The red lines show the approximate locations of the fiber optic cables. Fishermen are asked to please avoid dragging their fishing gear and downrigger balls on bottom in these areas!
Each of the fiber lines are held in place by multiple 10-pound navy anchors. Anyone needing the exact location of the fiber optic cable, please contact Phil Long (509) 531‐2987 with the Lake Chelan Research Institute. Researchers also hope to inspect the cable on bottom with an underwater drone.
Installation of the temperature sensing cables was made possible by the following organizations and individuals:
- Center for Transformative Environmental Monitoring Programs (CTEMPs, funded by the National Science Foundation, Oregon State University)
- Lake Chelan Research Institute
- City of Chelan
- Chelan County Natural Resources
- USDA Forest Service
- Chelan Ranger District, U.S. Forest Service
- Pinnacle Land Surveying
- John and Rayetta Browne
- Washington State Departments of Ecology, Natural Resources, and Fish & Wildlife
(By Phil Long, Lake Chelan Research Institute)