Quite a day! Wandering around the Mid Atlantic ridge, the only place in the world where it is above sea level would have to be the ultimate for anyone even vaguely interested in earth sciences. Today we are in the 'active zone'. Yes, I hear you say, but where is the actual fissure or 'line along the ground?'
Sadly, no such spot exists. The zone is many kilometres wide and is a fracture zone with fissures, cracks, craters and all sorts of processes going on. I had hoped we would find a line which we could straddle with one foot on the Eurasian plate and the other on the North American plate. Sadly that won't happen.
We have seen a variety of rock types, mainly basalts, in the last few days. But their form or structure has been radically different.
We have seen vast tracts of the 'hackly' or prickly basalt called 'ah-ah basalt' which is full of holes, called vesicles. This means the gas has been trapped in the molten rock as it cooled quickly. This could mean the magma erupted under water or ice or snow.
And still practising.. should have had all of Mary's head in the picture.
We have seen several cinder cones and tephra or pyroclastic cones.
Quite a few spots have fumaroles, mud holes or vents erupting steam. Below is a power plant which harnesses the heat by using the steam to drive generators for electricity. I need to check, but I think Iceland is 100% renewable energy.
New land being formed. So is this the place to buy real estate??
A still photo does not do justice to the mud fumaroles and the vents. The power is enormous and quite threatening when you stand near them.
And another selfie.
I could not resist a photo of the drying mud puddle showing the tendency towards hexagonal cracking as the mud dries and contracts. (OK, they are not perfect hexagons like columnar basalt but the mud is only a thin sheet.)
This steam vent was really 'pumping' and very warm to stand near.
The Viti crater last erupted in 1875, so not long ago. It is near the Krafla system. So these basalt layers, craters, fumaroles and geysers all result from the separating plates causing cracks and fissures across a wide zone of Iceland.
The steep-sided crater had no foot or hand holds, so it's a long way to the bottom - and cold!
This is the biggest power plant in Iceland and has several drill and core holes to harness the geothermal energy.
No bridge required. Just bend the pipes!
This barren, 'moon-like' surface, again the result of volcanism in the area, was allegedly used by the Neil Armstrong team to train, prior to the moon trip.
Some standard, almost 'text-book' strato volcanoes...
... and areas of solid basalt with no gas holes (vesicles) and a smooth appearance. So this stuff cooled quickly (small grains or crystals) but not so quickly that gas couldn't escape - so probably erupted onto land as lava flows.
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