Skjaldbreiður

Skjaldbreiður, recorded by Thingvellir

Skjaldbreiður of the driveway to Uxarhryggur

The Skjaldbreiður ( Isl wider plate) is a shield volcano in southwest Iceland. It is located in the municipality of Bláskógabyggð. It was created in an eruption about 9,000 years ago. The volcano is 1060 m high, its crater has a diameter of about 300 m. Its base diameter is about 15 km.

Hrafnabjörg

After Thor Thordarson Skjaldbreiður part of the volcanic system of Hrafnabjörg ( dt.Rabenfelsen ). This central volcano is located just southwest of the Skjaldbreiður towards Þingvallavatn. Other literature, however, assigns Skjaldbreiður to the volcanic system of Prestahnúkur.

Shield volcano eruptions after the Ice Age

The Ice Age ended about 10,000 years ago in Iceland and immediately thereafter, many shield volcanoes provide evidence for a phase of geological changes, which owes its origin to Skjaldbreiður.

The reason was the rapid rise of the country, which was freed from the burden of the glaciers. Changes in pressure and location of magma reservoirs can trigger such outbursts. At the same time the ice had closed columns that were open now.

Shield volcanoes can be detected on Iceland in the interglacials.

It involves predominantly effusive eruptions, such as back to the beginning of the 21st century can be observed in Hawaii. Typically, very hot and low viscosity lavas always emitted at such eruptions over a long period of years over decades to centuries by the same crater, so that layer upon layer of relatively shallow volcano builds.

Another shield volcano on Þingvallavatn is about Lyngdalsheiði.

Þingvallavatn

The resulting lava fields at the outbreak of Hrafnabjörg fill today partly the basin, where the largest Icelandic lake, which is Þingvallavatn. The former Thingstätte Althing is located in the lava fields in the canyon Almannagjá. Large parts of the area to be occupied by the Þingvellir National Park.

Rift zone

Due to the location directly above the geologically active site of the Mid-Atlantic Ridge, the lava fields of Skjaldbreiður were torn apart and deformed over the centuries. Today features a bizarre landscape with numerous cracks and crevices.

Because here two tectonic plates, the Eurasian and the North American one hand on the other, move apart, the area is still permanent deformations such as subjected to earthquakes. It is surrounded by four active volcanic systems (except the mentioned yet Hengill, Prestahnúkur and Hrómundartindur ).