LAVA Center Exploration!
We started our day with a 9:20 showing of a short cinematic piece that comprised of pictures and video clips of some of the more recent lava flows on the island. They also captured footage of the country’s response and how they protect the people who live here. After the cinema we walked into the exhibition that started off by showing the eruptions from the last ~100 years (1902 - 2015)
For each of the eruptions they quantified the amount of lava and tephra with a 1-7 scale. Grimsvötn has erupted most in the past ~100 years and has only ejected tephra. Hekla has been following a 10-year pattern recently but is 8 years behind missing its 2010 due date. There was lots of excitement around a possible eruption in 2013 but that died out. Hekla has had gaps in her past before; some lasting ~34 years. The next area talked about mantle plumes, hot spots, and magma.
The third portion of the exhibit was an informational area on eruptions and lava. They covered glacial, marine, and different types of land eruptions. Went in to details on what temperature and composition are associated with the variety of eruptions. They also covered lava types and what tephra and debris gets shot out of a volcano . The last room was a fun fact showroom. It gave you a panoramic of 5 volcanos and fun facts about each. The one I enjoyed a lot is how people considered Hekla to be the entrance to hell, and all the black birds that flew around this volcano were condemned souls.
Keldur: our second stop for the day. It’s is one of the oldest sod houses standing in Íceland. This house is believed to be erected in the 1200s. The last inhabitants left in 1946 when the husband of the house passed away. The government then took over the house to persevere and maintain its history. The family still runs the farm but no longer lives on the property.
DUCK!
You’ve now entered the house. These houses were made to be small; since it conserved resources and stores heat better. Resources like wood and metal were extremely rare and the area this house is located turf was rare as well. Turf is what typically comprised of the walls, since there wasn’t much around they used rocks and dirt. The walls of this house were 3 m thick which is how they kept warm during the winter. The wood they did manage to find was used for the frame of the house. The only metal object people usually owed was a cooking pot; they wouldn’t even use metal nails instead they used these wooden pegs. Something else that made this house unique and reflected the family’s wealth was the hidden tunnel. The reason they had one is because they would have been afraid that someone would come and kill them. Even with the wealth of this family couldn’t free them from the unsanitary living conditions of the times. All the kids and family mainly lived and did everything they needed too in just a few rooms. Women had several children seeing as 1/3 of them didn’t survive the first year.
On our way towards Hekla we passed the erosion center. They had several fields on both sides of the roads cut up into different test plots. They were growing different plants and seeing how/if at all they changed erosion. The issue that they are having with erosion is the inability to get a soil layer on top of the tephra which washes away as it rains. As we pulled up closer to Hekla we saw a tuya, which is a sub-glacial structure. We also saw what we believe is another tindar but may be a tuya. What makes Hekla so special and violent is due to its location and source of the magma. It sits on the corner of two zones; the East volcanic and a fracture zone. The Mid Atlantic Ridge provides hot magma from a depth of about 8 km. This magma enters the magma chamber and as it sits it separates. The gasses build up at the top, while your heavy elements sink to the bottom adding more Si to the mix. Hekla has erupted 18 times since people have settled on Island. These eruptions start with a plinian eruption. This is a column of tephra that shoots up into the air, about 9 km, looking like a mushroom cloud. This is typical of strata volcanoes and only last for about an hour. Then you have the second stage where it’s an effusive eruption, which happens when the sides weaken and starts to bulge. This is when a rift opens, and you have the out pouring of andesite, intermediate lava. This doesn’t flow as far as basalt which builds up a conical dome shape. This lava flow can last from days even months at a time.
