Spust v Thrihnukagigur, najgloblje vulkansko brezno na svetu

od Franc Malečkar · 12. 9. 2014

Deli:

Descent into the only lava chamber in the world till the black heart of Iceland using the facade glass cleaners elevator

Which country will be till the year 2114 at least 240 square kilometers greater, without wars, purchase and man operations? In which country almost every hill has birthday?

The descend by elevator through the volcanic throat with lava stalactites on the walls (bottom right) till the magma chamber of the volcano Thrihnukagigur

… before we find the answer, let’s go back for four decades. Armi Stefansson, then 22 year old student of mathematics, heard from shepherds about deep slit in one of the craters on the lava field of the Landscape park Blafjoll, about half an hour drive, ie. 20 km south, of Reykjavík. He estimated that it’s at least 100 m deep, judging by throwing stones. On the whole island was not so long rope, so he contracted with manufacturers of fishing gear to make it one. Unfortunately, it was too thick for climbing equipment. He tied himself to the end six colleagues made him descend. He reported about 130 m deep narrow slot because of poor lighting wasn’t possible to illuminate whole underground space. Rescuers used later the abyss for training and to found the prosecution into next abyss so that the total depth exceeding 200 m. He organized sixteen years later better equipped expedition. They found that this is the only preserved magmatic chamber in the world with vaulted hall with the ground-plan of three basketball courts in which could be inserted New York, Statue of Liberty, as well as 75 m high bell tower of the Evangelical-Lutheran Church Hallgrímskirkja from Reykjavik. A team of National Geographic magazine wanted to film these discovery. Rescuers have descended them into the basket for cleaning glass facades. This incentivated thoughts to make closer these unique discovery to a wider circle of curious . Former rescuers and experienced mountaineers founded the company that makes possible daily descend to 75 people in the till 14 members groups in the last three years, from late spring till early autumn.

In early September I have joined one of those who has gathered in the parking place near the agency headquarter in Reykjavik. We drove till the cottage in the foothill of the ski area. We could let the excess equipment and get rain coats..veather is a variable, warned an experienced guide and vulcanologist Tryggve. We followed him for about 45 minutes on the beautifully equiped track aver undulating lava field to the foot of the volcano Thrihnukagigur, which means „three peaks of craters“ and is pronounced “frinukagigur”. At the first stop, at the lava tube Djupihellir (Long Cave), we learned that Island is 16 million years old. It was formed due to separation of the North American and Eurasian lithospheric plates by pouring lava along the mid-Atlantic ridge. The Earth’s crust still move away of about 2 cm per year along a series of cracks in the direction of SE – NW and also Iceland continues to grow. Yes this is true, we have clearly learned on the next stop on the bridge over one and a half meter wide cracks. The guide explained that the edges spaced only a step at the beginning of their research. From here we had a nice view of the series of three volcanoes that stand less than 100 m above the plain. For the extreme north-eastern, in which we will also be descended, was found with radiomethric measurements that was created with lava escape under the icecap 4500 years ago. Why is preserved magma chamber is not yet clear, since there is no comparison. It is the only in the world. Normally would be filled with solidified lava or would collapse. It is believed that the smaller effusion of magma had been diverted in major outlet and it was “sucked” out of these chamber. The walls were splintering till the formation of the vault, which lasts the rock pressure. Vulcanologist H. Sigurdsson wrote: … Thrihnukagigur is unique, as if someone pulled the plug and magma should be drained from the chamber ..

Administrator Britnis received us in the base camp under the volcano. She served us tea and explained on a wooden mock the descent and safety requirements. We were helped to equip with safety belts and helmets with lamps. Towards the volcanic throat, we ascending in a 6 members groups. While waiting we were able to walk to a nearby lava tube and small craters. The base of one of them was reached climbing through over 40 m tall “chimney” on the roof of the magma chamber.

Elevators metal construction above the volcanic throat

Over about four meters wide and some meters longer entrance is placed metal structure. Jon, 21st century Charon, mountet on our belts the safety cord. So protected we reached the Germany made basket for cleaning glass facades. Slowly we descend into the abyss with illumionated tortuous lava strata and stalactites, that formed by its solidification, on the walls. About 50 m wide and 70 m long hall was gradually opening under us. We landed on gravel and immediately retreated over the “red line” that showed the danger zone, where stones from the pit could fall. The dome walls are multicolored bands of rock, generated by the action of hot magma. Brown are those who have more copper, yellow are richer in sulfur and red with oxidized iron. Black is colored original lava, which is possible to see along about 10 m wide fissure and lava tube in the wall. The ontact with an older volcano, covered by ash, it’s exposed on the walls foot. The guide introduced us the security and protection norms and gave us free for about a half-hour circular walk over the rocks, forming a conical-shaped hall floor. We had time to experience multicoulored dome wals where stands out black “heart”, geod similar lava tube. During our research were entering next groups, first as tiny lights under vault of the dome …

Belts of differently colored rocks, formed due the magma heat and the contact with old volcano (on the left)

Guide gathered us again in the basket and we started towards the surface … lamps at the bottom were becoming more and more similar to the underground constellation. The rainbow, rised over the Icelandic capital city on the horizon, received us at the top of the volcano. The edges of tle lava fields, overgrown with bright yellow-green mosses and lichens, were exposed arround the vulcano’s base. Britnis received us with a stew similar to slovene „jota“ and shared with us the excitement. We followed the guide over the plains of pahoehoe lava on the way back to the starting point. We could descend into a kilometer long lava tube Langihellir (Long Cave) with the the roof collapsed in several points. It was formed by the solidification of the surface of the river of lava which had flown out leaving cavities behind. Later the ceiling broke, which has enabled us to admire so shelves as stalactites solidificated in the direction of the lava current .

Ceiling collapse allowed the access into the lava tube Langihellir with stalactites in the direction of its flow.

I have tried to summarize the impressions on the way back to the Icelandic capital city over the rocky plains, with humps covered with moss. I agree completely with CNN reporter saying: ..one of the 20 places in the world that you must see before you die…

I would add that it is not only a remarkable natural phenomenon. It should be pointed as well on the developed sustainable tourist arrangement. It is enough to unscrew some screws and nature remain as it was before. All respect to the courageous and knowledgeable team!

More details about the descent into Thrihnukagigur, the deepest volcanic chasm, or. only magmatic chamber of the world, are on the link: http://www.insidethevolcano.com/