Today was the last day of the first excursion. The weather just seems to get better and better, with less clouds and much more sun, and probably the highest temperatures since coming to Iceland. Dettifoss, the large waterfall northeast of Akureyri, and the hot springs close to Myvatn were the most important stops today.
The road from Myvatn to Dettifoss leads through a desolate brown and grey coloured landscape made up of lava, lava, and glacially reworked lava. Huge end moraines indicate where the Icelandic ice sheet once halted on its final retreat. Wind-polished rocks and tiny arctic plants in sheltered areas show how harsh climatic conditions are here.
The waterfall at Dettifoss is impressive – a huge mass of water plunges into a deeply incised canyon, which is lined with beautiful vertical basalt columns. How long time did it take to create this 100 m deep canyon? How much water must have run through here during the last thousands of years? How old are the basalt columns?
A section through a remarkable feeder dyke of the Sveinar-Randarhólar crater is exposed alongside the canyon, and surrounded by horizontal black and red ash layers to the right and left. This eruption is dated to around 6000-8000 years ago, and gives us a maximum age for the incision of the canyon. It is amazing that such a deep canyon formed in such a short time.
Closer to Myvatn the soil emits steam and its hue changes to a yellowish brown and orange yellow. This is the place where sulphur appears at the surface and where a smell of rotten eggs fills the air. But it is also the place of the famous hot springs used for geothermal power production, heating and recreation. A well-known spot are the pools with hot water close to Myvatn, which attract tourists and geology students equally.
The first green patches appear around Lake Myvatn. It is one of Iceland’s larger lakes, a paradise for bird watchers and an oasis in the middle of all the dark lava fields. The lake is surrounded by green meadows with grazing sheep, lovely birch and larch forests, and dotted with small farms and villages. The tourist season has just started and the cottages, guesthouses and hotels will soon fill up.
This evening the first group of students will leave and the second group will arrive to Akureyri. The next four days will be spent exploring volcanoes, lava fields, hot springs, faults and rift zones, and with filming the students and the great landscapes.