The Álftaver cone group, have been a protected natural monument since 1975. In addition, the rootless cones are among the country's most remarkable natural sites and one of the unique Iceland volcanic activities.
Please respect the nature and bear in mind to treat the area with the given respect. Also note that hidden people settlements should also respected, hidden people have been observed near the hillocks.
Álftaver is a vast region bordered by the rivers Blautakvísel to the west and Kúdafljót to the east. The region get its name from the fertile wetland that typify the area. Above and to the west of the settlement is a group of rootless cones (pseudocraters); Álftaversgígar - Álftaver cone group.
The rootless cone group was formed during the Eldgjá eruption from 934 to 940, when lave flowed over the wetland. Initially the lava enters the lakes/wetland as realativly small pahoehoe lobes from set of tube entries at the active lava front. The insulating crust shields the hot lava in the lobe interiors from the water, which inflate and expand laterally in response to continued injection of lava.
As the lava thickness, it sinks into the water until the basal crust cracks. That enables the way for glowing hot lava into the water substrate and initiates steam explosions.
If the explosions are powerful enough, they burst through the overlying lava to emerage as rootless eruptions that build cones around the vents. As the flow migrates across the wetland, the process takes places multiple times in this area, which build a group of pseudocraters on top of the lava.
When the substrate is not as wet then the cones of spatter are produced, which are typically smaller and often conical. Cones of various sizes and types are present within the Álftaver group and this diversity has produces many intresting places.
To log this earth cache, please answer first the questions below and send the answers using Email function to me before you can log, thank you.
Attention!!! !!! EarthCache Guideline Updated 10 June 2019 !!!
- On the picture above you see a missing label (???). Look around the cones you stand and describe how you would describe in your own words it and how looks the lava today. Is there a difference between the drawing and the things you see?
- Look around. What is the typical (most common) cone type in this area? Describe the cone with your own words. How do the cones differ in size and shape? Any other points you can identify to differ the cones?
- One cone looks very special, you will easily find it which one is meant. It is allow to walk up on it. Describe at least with 5 different attributes (e.q. high, size, shape, from, colour, unique brand, etc.) what is unique on this cone.
- Take a picture of you or a personal object and your geocaching name / geocaching logo on a paper within the cave in background. Please upload the picture with the log. Do not bother editing picture with Photosphop or likewise, e.g. insert name in the image.