BACKGROUND ON THE AREA
Reykhólar is a place of natural beauty and historical interest. There is a lot of geothermal heat in the surrounding area.The village is also famous for its kelp factory, the only factory in Iceland that processes seaweed. The products are used in food, animal fodder, fertilizers and for medicinal purposes.
The hill where the village Reykhólar stands on, with the church at its highest point, consists of geyserite, a silicate that has petrified from the hot water throughout history. You will therefore see little gardens in this village...
** Free translation from Icelandic **
There is a considerable amount of geothermal energy in the area, with the main thermal zone at the south of Reykhólahæð. All major clusters in the area appear to be related to passages and or fissures running from the northwest to the southeast from Höllustaðalaug through Reykhólar to Einireykir at Langavatn.
The bedrock is made up of a basaltic lava flow (traditional tertiary earthquake) which flowed for 10 to 11 million years ago. According to Haukur Jóhannesson, geologist, basaltic lava flow and the original thin red soil are mixed here. Three big fissures go through the area and their direction is northeast - southwest. They are: Grundarvogsmisgengið (to the west), Stekkjarvogsmisgengið (in the middle) and Neðravatnsmisgengið (easternmost) - see the figure: the red lines indicate the fissures.
Surprisingly, human power and drilling of bore holes at Reykhólar seems to have not affected the area; the first bore hole for hot water was drilled in Reykhólar in 1967 and then received about 15-20 L / s of 100 ° C hot water. Over time both temperature and flow have changed.
** End of free translation **
Haukur Jóhannesson, 2013
The area is commonly called Einireykir and deduces its name from Einireykjahver, which was used for bathing and washing from Miðhúsum. Historical pictures show the bathing and washing activities performed at this location.
Since 1967 hot springs have moved and disappeared within the village of Reykhólar. However, the total amount of hot water in boreholes has not changed that much over the last 50 years. At the time the temperature at the first borehole was 114°C and it is now about 112°C. The ISOR organization, which performs geosurveys in Iceland, monitors the geothermal activity.
The birdlife at Reykhólar is extremely diverse and reaches its peak in spring and summer and can be estimated at 70 bird species every year. The area enjoys special protection under the Nature Conservation Act. The Reykhólar community is having a role in the protection of the birds and their nests. Despite this, there are no limitations to enter this area. However: mind your step and stay away from birds and especially their nests.
We enjoyed the local hot springs in Reykholar and hope others will enjoy them as well:
It is nice and quiet and the walk there is short (but far from paved...)
As there are no information signs at or near the site, this earch cache is more complex to answer than quite some others: you have to carefully read the listing to be able to answer the question. If that is not your piece of cake... well, select another earth cache. There are plenty in Iceland.
BACKGROUND ON EARLY LIFE
Life as we know it may have first arisen more than three billion years ago in a high temperature environment of boiling water. Thermophilic bacteria in hot springs may be relict populations of the first life on earth; these thermophilic bacteria may be the ancestors of all other life forms.
Definition of cyanobacterium
Any of a major group (Cyanobacteria) of photosynthetic bacteria that are single-celled but often form colonies in the form of filaments, sheets, or spheres and are found in diverse environments (such as salt and fresh water, soils, and on rocks).
Cyanobacteria were more commonly grouped with algae in the past because they possess a type of chlorophyll (chlorophyll a) not found in other bacteria and because they produce oxygen as a by-product of photosynthesis.
These cyanobacteria evolved in Precambrian times when there was absence of free oxygen in the atmosphere. By producing and releasing oxygen (as a byproduct of photosynthesis), cyanobacteria are thought to have converted the early oxygen-poor, reducing atmosphere, into an oxidizing one, causing the Great Oxygenation Event and the "rusting of the Earth", which dramatically changed the composition of the Earth's life forms and led to the near-extinction of anaerobic organisms.
BACKGROUND ON HOT SPRINGS
A hot spring is a spring produced by the emergence of geothermally heated groundwater that rises from the Earth's crust. There are geothermal hot springs in many locations all over the crust of the Earth. While some of these springs contain water with a safe temperature for bathing, others are so hot that immersion can result in injury or death.
Alkaline hot springs support colonies of bacteria that utilize hydrogen sulfide for their energy source: many cyanobacteria have the ability to photosynthesize under aerobic or anaerobic conditions. Under anaerobic conditions, in the presence of sulfur, electrons are derived by the reduction of sulfur:
CO2 + 2 H2S --> in the presence of light and chlorophyll --> CH2O (sugar) + H2O + S
These photosynthetic bacteria are restricted to photo-anaerobic habitats.
Common cyanobacterial species in alkaline hot water springs are Mastiglocladus Laminosus and Chloroflexus; Mastiglocladus Laminosus is a blue-green bacteria that has its optimum growth temperature between 45-60°C. Chloroflexus is a green bacteria that turns orange due to H2S-depending photosynthesis. Its optimum growth temperature is 60-70°C. These orange-coloured cyanobacteria generally occur in water that has cooled below 73°C; The green chlorophylls in these photosynthetic bacteria are masked by orange carotenoid pigments. These carotenoid pigments protect the delicate cells from intense solar radiation, especially during the summer months.
TO LOG THIS EARTH CACHE YOU NEED TO
Visit the (above) listed coordinates, observe the water and its surroundings
By reading the information on the cache:
- 1a) Describe the colours inside the water
- 1b) Estimate whether the hot spring water (at wp1) is alkaline or acidic
- 1c) Explain the distribution of the colours you observe
Visit the coordinates of Stage 2, and observe the water and its surroundings
Compare your observations at wp1 with those of wp2:
- 2a) Explain the difference(s) in the colours inside the water
- 2b) From a geological point of view, what can you deduce from these differences?
Comparing the two waypoints and continuing on the previous questions:
- 3) Under what circumstances would you only see 1 colour at wp1?
Send your answers in ENGLISH or GERMAN or DUTCH to our e-mail address available via our geocaching profile:
1) GC7CVVG - Reykhólar hot springs
2) your log name
3) provide the answers to question 1a, 1b, 1c, 2a, 2b and 3
We will provide feedback to your answers. Once you have shared your anwers with us, feel free to write your log and upload your picture(s).
! Never provide any answers in your log or else we have to delete your log without warning
! Optional: We appreciate you express your experiences at the site by sharing at least a picture of the area but without revealing any answers.
ACKNOWLEDGEMENT
A special thanks goes to Mrs. Maria Maack, biologist / geologist at Reykhólar, for her contribution on background material and her supportive suggestions.
LITERATURE
- bore hole measurements, http://www.os.is/gogn/Skyrslur/OS-1982/OS-82030.pdf
(1982)
- http://www.reykholar.is/stjornsysla/adalskipulag/skra/1621/
- Reykhólahreppur General Plan 2006-2018
- http://site.iugaza.edu.ps/elnabris/files/2015/03/3_Cyanophyta.pdf
- https://www2.palomar.edu/users/warmstrong/ploct97.htm
- https://www.merriam-webster.com/dictionary/cyanobacterium
- https://en.wikipedia.org/wiki/Cyanobacteria