Myvatn Nature Baths EarthCache
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Mývatn Nature Baths are geothermal spas often called the Blue Lagoon of Myvatn. The Baths are located in a geothermal area just east of the Grjotagja rift. Some say they are “like the Blue Lagoon only cheaper, quieter, more natural. Where the Icelanders rather than tourists go.”
Iceland is situated on the Mid-Atlantic Ridge. Here separation of the North American and Eurasian plates are partly responsible for Iceland being one of the most active volcanic regions in the world.
The Mývatn-Krafla area is part of this rift zone. The area of Mývatn Nature Baths is marked with red on the map:
Generally thermal springs can be found in areas with higher volcanic activity or near deep reaching flow systems. The water is thereby heated subterraneously - either by volcanic activity or as water circulates through deep layers. In doing so the water can reach temperatures near the boiling point.
The Krafla geothermal power station takes advantage of the volcanism in the area and its run-off is used in the Mývatn Nature Baths. The site is also home to the first drill hole of the Iceland Deep Drilling Project. The drilling is at a plate margin on the mid-oceanic ridge, and involves drilling down to the lava where large quantities of water can quickly be heated to over 400°C. The project aims to drill around 4 km below the surface. But at Krafla the scientists and engineers hit lava at just 2,500 metres.
The temperature in low temperature areas is usually around 100 C at 1000 m depth and increases slowly below that. For instance a temperature of 142 C has been measured in a 2000 m deep drill hole in Reykjavík. The second highest geothermal water temperature measured in Iceland is 340 C at 2000 m depth here at Krafla at Mývatn. (Highest temperature is 380 C at Nesjavellir). Besides the temperature the main difference between water from low temperature and high temperature areas is the amount of dissolved minerals and material in the water, as the temperature is much higher. (Source: Porleifur Einarsson: “Geology of Iceland: Rocks and Landscape”).
Mývatn Nature Baths
Throughout the history the local people of the Myvatn area have used the natural steam for bathing. The tradition was to build a stone shelter over a steaming fissure and then people went in to bath in the moist steam.
The water for the main pool of today is geothermal water drawn from depths of up to 2500 meters.
Notice that it is not necessary to pay money to answer the questions.
1. Go to the place to cache coordinates point to. Describe the sound coming from it. What temperature is mentioned? What do you think it is? What is it used for?
2. Look at the water in the main pool and the stones at the water edge. (You do not need to enter the pool area to do so). Describe the water with your own words: What colour is the water? Is it clear? Does it smell? Could it have a content of minerals and dissolved material? Visitors to the Mývatn Nature Baths are required to take of some types of jewellery. What sort? Why do you think that is?
3. Optional: Take a picture of your GPS and the bath and post it with your "Found it" log. You may also be in the photo.
4. Send your answers to my profile at geocaching.com before logging online. You need not wait for my answer to log your find. I will contact you if there is a problem with your answers.
Important! Do not write the answers in the log and do not post pictures of the signs. I will have to delete your log if you do.
Logs without answers emailed to CO before (or within minutes) of logging will be deleted without any further notice. If you cannot send the answers, then wait with the online log. Please do not expect me to reply to your mail/message. If your answers are good (95% of visitors), I will not contact you.
You have to have been at the location after the release date of this cache - old holiday visits do not count and are not accepted.
(No hints available.)