View of Þingvallavatn
This is the view to the southwest from the overlook at Hakið in Þingvellir National Park in southwest Iceland. Þingvallavatn, the lake in the photo, is the largest natural lake in Iceland. The northern reaches of the lake lie within the National Park. Þingvellir, Iceland’s First National Park, stands out both for its natural beauty and its incredible role in the history of Iceland.
Its history dates from 930 AD when the ancient parliament of the Viking parliament was organized. Þingvellir translated literally means "Assembly Plains”. The Parliament, called The Alþing, met at Þingvellir from 1799 to 1844 even throughout the Icelandic Civil War in the 13th Century. In 1844 the Alþing stopped meeting due to Danish colonialism. The Alþing started meeting again sporadically in 1848 in Reykjavik. It was 1907 before the Alþing started meeting regularly also in Reykjavik. In 1928, just before the 1000 anniversary of the foundation of Alþingi in 1930, the parliament made Þingvellir a National Park. When Iceland declared it independence from Denmark in 1944, the ceremony was held Þingvellir.
While Þingvellir’s cultural and historical heritage draws many visitors, it’s geological history is also fascinating. The park sits on the Mid-Atlantic Rift with its west side on the North American tectonic plate, while east side lies on the Eurasian plate. In Iceland, the rift is above sea-level, and nowhere can you see the edges of both plates as clearly as in Þingvellir. The plates are bounded by a series of cliffs with a rift valley in between. This rift valley forms the main geologic feature in the park.
Þingvallavatn fills the lowest portion of the rift valley and fingers of water from the lake extend up into the faulted fissures on its north side (toward the photographer).The lake covers an area of 84 square kilometers (32 square miles), and reaches a depth of 114 metres (374 feet) at its deepest point. In the photo the Island visible is a cinder cone (volcano) called Sandey that rises above lake level.
One of the fissures can be seen in the foreground on the left side of the photo. These crack form along the bounding faults of the rift valley. About 2000 years ago, basaltic lava erupted from fissures and flowed into the valley. In the center of the photo ropy hardened lava can be seen near the fissure. Geologists call basaltic lava that exhibit a smooth, hummocky, or ropy surface pahoehoe. Volcanoes surround the Þingvellir area and some can be seen on the photo’s distance. The rift has a long eruptive history with the 2000 year old flows being the most recent. However, they may not be the last volcanic flows as the area is still rifting and more volcanic activity is possible. The valley floor is a linear block that has subsided as the valley walls were pulled apart by plate motions. The valley walls are moving apart at a rate of about 7 mm per year. Geologist estimate that during the past 9000 years the valley grew on the order of 70 m. Along with getting deeper, the valley is getting wider. The floor subsides at a rate of about 1 mm per year. Over the last 9,000 years the valley deepen due to subsidence by about 40 m. Rifting within the graben is episodical, with the last major earthquake activity occurring in 1789. During the 1789 earthquakes the graben floor subsided 1-2 m.
References:
icelandroadguide.com/items/hakid/
guidetoiceland.is/connect-with-locals/jorunnsg/ingvellir-...
notendur.hi.is/oi/geology_of_thingvellir.htm
www.thingvellir.is/en/history-nature/history/
icelandmag.is/article/9-essential-things-know-about-thing...
View of Þingvallavatn
This is the view to the southwest from the overlook at Hakið in Þingvellir National Park in southwest Iceland. Þingvallavatn, the lake in the photo, is the largest natural lake in Iceland. The northern reaches of the lake lie within the National Park. Þingvellir, Iceland’s First National Park, stands out both for its natural beauty and its incredible role in the history of Iceland.
Its history dates from 930 AD when the ancient parliament of the Viking parliament was organized. Þingvellir translated literally means "Assembly Plains”. The Parliament, called The Alþing, met at Þingvellir from 1799 to 1844 even throughout the Icelandic Civil War in the 13th Century. In 1844 the Alþing stopped meeting due to Danish colonialism. The Alþing started meeting again sporadically in 1848 in Reykjavik. It was 1907 before the Alþing started meeting regularly also in Reykjavik. In 1928, just before the 1000 anniversary of the foundation of Alþingi in 1930, the parliament made Þingvellir a National Park. When Iceland declared it independence from Denmark in 1944, the ceremony was held Þingvellir.
While Þingvellir’s cultural and historical heritage draws many visitors, it’s geological history is also fascinating. The park sits on the Mid-Atlantic Rift with its west side on the North American tectonic plate, while east side lies on the Eurasian plate. In Iceland, the rift is above sea-level, and nowhere can you see the edges of both plates as clearly as in Þingvellir. The plates are bounded by a series of cliffs with a rift valley in between. This rift valley forms the main geologic feature in the park.
Þingvallavatn fills the lowest portion of the rift valley and fingers of water from the lake extend up into the faulted fissures on its north side (toward the photographer).The lake covers an area of 84 square kilometers (32 square miles), and reaches a depth of 114 metres (374 feet) at its deepest point. In the photo the Island visible is a cinder cone (volcano) called Sandey that rises above lake level.
One of the fissures can be seen in the foreground on the left side of the photo. These crack form along the bounding faults of the rift valley. About 2000 years ago, basaltic lava erupted from fissures and flowed into the valley. In the center of the photo ropy hardened lava can be seen near the fissure. Geologists call basaltic lava that exhibit a smooth, hummocky, or ropy surface pahoehoe. Volcanoes surround the Þingvellir area and some can be seen on the photo’s distance. The rift has a long eruptive history with the 2000 year old flows being the most recent. However, they may not be the last volcanic flows as the area is still rifting and more volcanic activity is possible. The valley floor is a linear block that has subsided as the valley walls were pulled apart by plate motions. The valley walls are moving apart at a rate of about 7 mm per year. Geologist estimate that during the past 9000 years the valley grew on the order of 70 m. Along with getting deeper, the valley is getting wider. The floor subsides at a rate of about 1 mm per year. Over the last 9,000 years the valley deepen due to subsidence by about 40 m. Rifting within the graben is episodical, with the last major earthquake activity occurring in 1789. During the 1789 earthquakes the graben floor subsided 1-2 m.
References:
icelandroadguide.com/items/hakid/
guidetoiceland.is/connect-with-locals/jorunnsg/ingvellir-...
notendur.hi.is/oi/geology_of_thingvellir.htm
www.thingvellir.is/en/history-nature/history/
icelandmag.is/article/9-essential-things-know-about-thing...