Welcome to the Willow Creek Hot Springs Earthcache! An Earthcache is a special type of geocache where there is no container to find - instead you are looking for a unique geological feature of the area and need to answer questions, as well as posting a picture, in order to claim the find.
To claim a 'find' for this Earthcache you must answer the following questions and send your answers in a message or email to the owner using the link at the top of the page. You can log your find with a photo at GZ. Send your answers to the tasks. I will be in contact if there is a problem, no need to wait for a response as long as the required photo is included in your log.
1. Using a thermometer, take the water temperature of both the larger pool and the smaller pool. What is the difference between the temperature of the two pools? In your own words, explain why you think the temperature differs between the two pools.
2. Estimate the size of both pools. Using the formula length x width x average depth, estimate the volume of the two pools. What is the difference in size? Do you think this contributes to the difference in the temperature between the two pools?
3. Standing at the posted coordinates, is the source of the hot spring visible? Based on your observations, do you feel that this is a true hot spring, or could other sources (rainfall, human interaction) contribute to the water levels in the pools?
4. Optional - Post a photo of yourself, your signature item, your GPS, at or near the posted coordinates. You do not need to show your face if you are shy. You may include this photo in your log, or send it with your answers.
EARTHCACHE DETAILS
Miles away from civilization, Willow Creek Hot Springs is located in the middle of southeast Oregon’s high desert region. An all-season gravel/dirt road will get you most of the way there, but the last bit is on soft dirt, which is impassible during rain.
What are Hot Springs?
A hot spring is the emergence of geothermally-heated groundwater from the earth's crust. Hot springs are created when rain and snow seep below Earth's surface as groundwater, until hitting solid rock and collecting in pools, or aquifers. Magma heats this water, which then rises back up to the surface through cracks in the earth's crust, called vents, forming a hot spring.
Because heated water can hold more dissolved solids, hot springs also often have a very high mineral content, containing everything from sulphur and calcium to lithium and iron. When the water containing the dissolved minerals reaches Earth's surface, the water cools and minerals come out of solution depositing along the spring's edge.
So What About Willow Creek Hot Springs?
Water issuing from a hot spring is heated with heat produced from the Earth's mantle. Willow Creek Hot Spring is an example of a hot spring in an area without volcanic activity - as water percolates into the Earth's crust, it is heated by the rocks it comes in contact with. The temperature of rocks within the earth increases with depth according to the geothermal gradient. This generally takes place along faults, where shattered rock beds provide easy paths for water to circulate to greater depths.
Much of the heat is created by decay of naturally radioactive elements such as uranium-238, uranium-235 and potassium-40. An estimated 45 to 90 percent of the heat escaping from the Earth originates from radioactive decay of elements mainly located in the mantle. This heat flows through the crust by a slow process of thermal conduction. The temperature underground increases about 2°C for every 100 m in depth. At depths of 5 km or more, the rock temperature is at or above the boiling point of water—at the surface however the water does not boil underground due to immense pressure under the Earth's surface.
