Krafla
Virtual
Field trip

Krafla Introduction

Krafla is an exceptional place for many reasons... The following video will introduce you to the Krafla volcano, the Krafla geothermal features and a bit of the history of volcanic eruptions at Krafla. Once you've finished the video, you can attempt the first exercise below. Once you get it right, you will be able to continue on your journey!

Can you find Krafla on the map?

Use the information that you learnt from the previous video to locate Krafla on the map. You might find that the volcanics and tectonics maps might be useful to locate yourself, just click on the buttons to activate them. You can also make Google maps fullscreen by clicking the button in the top right corner. There is a transparency slider in the bottom left. If the legend gets in the way, just click on it and it should disappear! You can always make it come back by clicking the 'Show legend' button.

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Icelandic Mythology

On the northwest side of the Krafla caldera is Víti an explosion crater, which is 300 metres in diameter. The name Víti, meaning Hell (in Icelandic), comes from the old belief that hell was located under volcanoes, so the Krafla Caldera is “Hell on Earth”.

Dimmuborgir, or the Black Fortress, is a dramatic expanse of lava in the Lake Mývatn area. Somewhere hidden inside Dimmuborgir you might stumble upon Jólasveinahellirinn - the Cave of the Yule Lads! The Icelandic Yule lads are 13 very ill-mannered and inquisitive trolls. They are the sons of the two terrible trolls, Grýla and Leppalúði! On the thirteen nights before Christmas, these trolls come to terrorise the Icelandic people, each with their own strategy after which they were named. Listen to Ben’s videos to find out more about these trolls.

Let's find out what you know!

Continue

Tuff cone, rootless cones and caldera volcanoes

Krafla is an amazing place where you can find a range of volcanic features, from some of the smallest to some of the largest that we know of!

Tuff cone

What is a tuff cone?

Which of the following statements best describes how a rootless cone forms?

 

More questions...

Re-organise these events into the correct chronological

Use the 3D viewer below to explore distinctive features, then select the descriptions for features. Left click on the map to travel around, right-click tilts the view.

 

A'a Flows

360 Video!

What unusual features are present in the previous video that are not normally seen in A'a' lava flows (select more than one)?

 

Rhyolite and Obsidian flows

This section is about describing obsidian and rhyolite outcrops. You can watch the video, then keep scrolling and give the next exercise a try.

Outcrop description

Make observations of structural features to inform the orientation of the rhyolite (main rock type in image). Note the relationship with the weathered basaltic country rock in the bottom right corner of the image. You can look at the outcrop in 3 dimensions if you wish, by clicking on the checkbox below the image. Left click on the map to travel around, right-click tilts the view.

This outcrop is Hrafntinnuhryggur, an outcrop of Obsidian material. Use the 'Enable 3d content' to see the outcrop in 3D! Describe the columnar jointed lava. Once you've filled in something for each value, you'll get to continue on your journey! If you are not sure which one this is- then go check out this figure from Tuffen & Castro 2009.Scale is on bottom right.

Questions
What proportion of the outcrop is
Anything Else?

What additional observations might be important in working out how this outcrop formed?

Continue

Let's judge someone else's work!
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Outcrop

Sketch judging

See what others have said!

What can be improved on this sketch?

What was done well on the sketch?

To see what grade other have given, click here!

Continue

Obsidian and hyaloclastite rocks

This section is about describing obsidian and hyaloclastite rocks, both found at Hrafntinnurhyggur. You can watch the video, then keep scrolling and give the next exercise a try.

Rock description

Make observations on the lustre, fracture, crystals, and flow bands of this rock. This will inform you about the cooling and emplacement of the outcrop it was sourced from. This rock was taken from the jointed outcrop you just described.

Rock Description
What textural features can you see in the rock above?

Flow features

 

Recrystallisation

 

Fractures / Cleavage

 

Textures

 

Rock description.

The rock below was taken from the orange/tan outcrop , a little below the jointed outcrop you described earlier.

Rock Description
What textural features can you see in the rock above?

Flow features

 

Recrystallisation

 

Fractures / Cleavage

 

Textures

 

Outcrop Summary

You've succesfully completed Krafla....
...Part 1!