No single place epitomizes the history of Iceland and the Icelandic nation better than Þingvellir by the river Öxará.
At Þingvellir – literally “Parliament Plains” – the Alþing general assembly was established around 930 and continued to convene there until 1798. Major events in the history of Iceland have taken place at Þingvellir and therefore the place is held in high esteem by all Icelanders. Today Þingvellir is a protected national shrine. According to the law, passed in 1928, the protected area shall always be the property of the Icelandic nation, under the preservation of the Alþing.
LÖGRÉTTA-THE LAW COUNCIL
Lögrétta was the legislative assembly and therefore the supreme institution of the Alþing in the Commonwealth period. The work of the Lögrétta was multifaceted as it settled disputes, passed new laws and granted exemption from laws.
The Law Speaker governed Lögrétta meetings,at which 48 chieftains sat on a central platform. Each chieftain had two advisors who sat in front and behind him.After the bishoprics at Hólar and Skálholt were established, the bishops also had seats at the Lögrétta. The number of men who sat at the Lögrétta was thus 146, or 147 if the Law Speaker wasn’t a chieftain. The Lögrétta met on both Sundays included in the general assembly, as well as on its last day, and more often if the Law Speaker so desired. Everyone was free to follow the proceedings of the Lögrétta, but no one was allowed to stand within the terraced area.
As the 13th century proceeded, increased animosity between chieftain clans ended when Icelanders yielded to the authority of the Norwegian king in 1262 with Gamli Sáttmáli. This treaty made Lögberg redundant and the Lögrétta became the only entity of the Alþing, which then became a court of law with limited jurisdiction. At a gathering in 1662, the Lögrétta members agreed to acknowledge the absolute rule of the Danish king. At that point, the responsibility and power of the Alþing diminished until the last meeting at Þingvellir in 1798.
Until the 16th century the Lögrétta was located on theeastern side of the Öxará river. In the 16th century, due to changes to the Öxará river, Lögrétta became isolated on a small islet and hence was moved west of the river in 1594, where a small building was constructed for it. All assembly proceedings took place in this building until 1798.
In the last few decades, research has made it clear that Þingvellir is a natural wonder on a international scale, with the geologic history and the biosystem of Lake Þingvallavatn forming a unique entity, a magnificent showcase.
Being able to witness the evolution and formation of new species in a place like Lake Þingvallavatn is of immense value.
The Þingvellir area is part of a fissure zone running through Iceland, being situated on the tectonic plate boundaries of the Mid-Atlantic Ridge.
The faults and fissures of the area make evident the rifting of the earth’s crust.
In the summer of 2000, two severe earthquakes occurred in South Iceland. Though their source lay 40-50 kilometres southeast of Þingvellir, stones fell from the ravine walls and water splashed up from the rifts. The water in the Flosagjá rift, normally crystal clear, became so murky that you couldn’t see the coins lying on the bottom. The earthquakes were a result of movement of the Eurasian and North-American plate boundaries that run through Iceland. In the south, the plates inch past each other, but at Þingvellir, they break apart and the land between subsides. Away from the plate boundaries the activity is fairly constant, about two centimetres a year, but, in the rift zones themselves, tensional stress accumulates during a long period and is then released in a burst of activity when fracture boundaries are reached. The most recent burst of activity swept over Þingvellir in spring 1789.
Iceland owes its existence to a mantle plume that produces twice as much volcanic matter as the Mid-Atlantic ridge. The mantle plume is located east of the ridge channel, but the eruptive belt tends to follow the plume, and it’s there that volcanic activity is greatest.
The earthquake zone is formed where the eruptive belt is shunted. In the eruptive belt, a new earth crust is formed that accumulates at the fault edges and gradually drifts away. The oldest rocks in the country are thus found a long way from eruptive belt, in the east and west of the country. Þingvellir is in a seven-kilometre wide graben that lies between the Almannagjá and Heiðargjá faults. It’s covered with 10,000 year-old lava that originated in a crater south of mount Hrafnabjörg.
During the time since the lava flowed, the land subsidence has been about 40 metres and the spreading or rifting about 70 metres. The rift valley is part of an active volcanic and fissure region that extends north from just outside the Reykjanes area to the Langjökull glacier. The outer boundaries of this are the Súlnaberg rock face in mount Botnssúlur and, in the east, mounts Lyngdalsheiði and Laugarvatnsfjall.
The landscape at Þingvellir is now quiet different to that at the time when Grímur geitskór chose the site for the general assembly. In the Sturlunga Saga it is said that the river Öxará had been diverted into Almannagjá and onto Þingvellir. The river Öxará then changed the appearance of the site through sedimentation, and land subsidence caused encroachment of water up to the assembly site. We can assume that the subsidence amounts to almost four metres from when the Alþing was established in 930.