Krýsuvík (volcanic system)

[1] However, there are some indications—namely, the discovery by geophysical methods of what scientists interpret as a buried caldera, combined with the well-known, vigorous hydrothermal system above it—that an embryonic central magma chamber may already exist or be actively developing.

[3] The volcanic systems are arranged en echelon and at an angle that varies from 20 to 45° to the direction of the rift zone on the divergent plate boundary traversing Reykjanes.

This suggests that it could eventually develop into a central volcano like the similar, but more mature Hengill volcanic system farther to the east on the peninsula.

[5] The Krýsuvík fires were a period of volcanic activity which started in the middle of the 12th century, probably in 1151 and written sources indicate that they ended in 1188.

There is a prehistoric maar complex around Grænavatn at Krýsuvík which has its origin in phreatic explosions connected to a period of effusive eruptions.

[11] These are some lava fields which originated in eruptions of the Krýsuvík volcanic system since the end of the last glacial spell 13,000 years ago.

Around 8,000 years ago, the Búrfell crater near Hafnarfjörður produced a 18 km2 (6.9 sq mi) lava field called Búrfellshraun [ˈpurˌfɛlsˌr̥œyːn].

The Seltún [ˈsɛlˌtʰuːn] geothermal area is situated next to Krýsuvík in direction of lake Kleifarvatn (Route 42) and at the foot of Sveifluháls hyaloclastite ridge.

Here solfataras, fumaroles, mudpots and hot springs are formed; the soil is coloured bright yellow, red, and green caused by iron oxidation, sulfur and calcite precipitation.

The German scientist Robert Bunsen visited the site in 1845 and, based on research there, proposed a hypothesis on formation of sulfuric acid in nature.

[15] Also found in the area are the Ögmundarhraun [ˈœɣˌmʏntar̥ˌr̥œyːn] lava field from the 12th century as well as some Pleistocene subglacial mounds and formations like Helgafell, Sveifluháls and Trölladyngja.