Let the Adventure Begin!
Today's the first day of our Iceland adventure! We started off the day with a lecture in our Geocamp from Oly. He gave us an introduction to Iceland geologic origins and the general geology of the island. Today is particularly interesting because there is a glacial flood event happening on the Myrdalsjokull glacier which unfortunately we cannot get to. Because of all the rain, a kettle has developed, which is a crater in the glacier with geothermal energy underneath. Every 30 to 40 years these kettles will collapse and create a glacial flooding event. An event like this can release about 1,300 cubic m³ per second of water.
During the lecture we discussed various eruptions throughout recent history. An interesting fact that Oly pointed out was that volcanic names are Celtic not Nordic in origin and usually female. We learned about the Laki eruption of 1783 which was the only flood basalts to occur during human existence. The Eyjafjallajokull eruption of 2010 haulted air travel throughout the continent of Europe for many weeks as it blasted ash and debris into the atmosphere. In 2014 there was a fissure eruption at Bárdarbunga which opened at the rift zone and was the second largest flood basalt during human existence. Just south of that eruption, there is a 600 to 800 m thick ice sheet vulnerable to such an event.
I asked if sea level rise was a concern amongst Icelanders. It is not. There are only a low-lying salt marshes in the south west of the country which are uninhabited. The Island is also isostaticaly rebounding so the coastline is actually uplifting and relative sea level is falling, causing the shoreline to retreat.
We will be traveling today to the 150 to 200,000 year old Peninsula called Reykjanes. The island of Iceland sits on a hotspot and over an active mid oceanic ridge known as the Mid-Atlantic ridge cuts right through, explaining the active volcanic landscape, with shield volcanoes erupting from 12000 to 2000 years ago. The bend in the Mid-Atlantic Ridge that occurs within Iceland is caused by this hotspot. Tumuli is a volcanic landform term that we learn today. This is how they form: lava flow develops a crust on top, flowing lava builds up underneath pushing up a dome shape in the hardened crust, these dome shaped tumuli then begin to crack open like a loaf of bread, and as the lava cools and solidifies this landform is left on the surface.
Our second lecture was given by Oly's son Bjorn at the Keilir school down the road. He spoke to us about renewable energy in Iceland. About 12 miles under the surface at 100 miles wide and 370 miles deep there is a super heated plume that created Iceland and fuels the geothermal energy. High temperature feels along the rift zone provide the steam needed to supply electricity and low temperature feels heat homes, pools and bathing water. In the 1930s ice and begin distributing the geothermal heat to residential homes. The city of Reykjavik has the largest district heating system in the world. Iceland even pumps geothermal water into parts of the ocean during summer for recreation on beaches.
Icelanders of the highest years of energy per capita in the world. However although this may sound discouraging about 86% of their total use is renewable energy. There are five large geothermal power plants located along the rift zone. Much of Iceland electricity is used for aluminum smelting, a large industry in Iceland. Hydro power is also used throughout Iceland. There are 10 large plants and many smaller plants that individual farmers in villages utilize.
There are only two windmills in Iceland due to the fact that they simply do not need more electricity production and even if they did, the winds on Iceland are too gusty and not steady enough for ideal energy harnessing through wind power.
After lectures we hit the road. We travel to the West Coast of the peninsula and step foot on a shield volcano surface with the secular columnar basalt formations. The columnar shapes occur as the basalt cools and shrinks leaving behind columns resembling pentagon all shapes. This basalt is between 14,000 and 15,000 years old, deposited through fissure eruptions during that time.
Stop number two took us to the bridge between the continents. This is a grabbed rift feature within the Mid-Atlantic Ridge rift system. Somewhere along these rifts is the separation between the Eurasian plate to the east and the North American plate to the west. The fissure has filled with wind and rain eroded sediment from the surrounding basalt rock. These plates are separating in either direction at about 1.8 cm per year.
Stop number three was our lunch spot and brought us to the coast just south on the peninsula where we could see evidence of three different eruptions. One occurred during the 1200s and was a pyroclastic eruption. The other two occurred about 6000 years ago and then 12,000 years ago and were both fissure eruptions.
After lunch we viewed a large geothermal vent called Gunnuhver which has shifted hundreds of meters since the 1960s and has been going full blast 24 hours a day, seven days a week since then.
We stopped then at a cinder cone which had been mined where we collected scoria samples of various colors from the site. The cinder cone cannot slope any steeper than 30° due to the angle of repose.
On the way home, we drove past flood basalts from the eruptions in the 1200s in the eastern part of the peninsula, and investigated thick moss bedding which developed over the earlier layer of flood basalts.
Great way to start out the trip!