Kolbeinsey Ridge

No photo available for this volcano
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 66.67°N
  • 18.5°W

  • 5 m
    16 ft

  • 375010
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Bulletin Report: October 1999 (BGVN 24:10) Citation IconCite this Report


Submarine eruption or dike intrusion south of the Spar Fracture Zone

A submarine eruption or dike intrusion on 30 August 1999 was identified by seismic events from the Icelandic Seismological Network (SIL) at the Vedurstofa Islands. The swarm was centered ~180 km N of Grimsey and 100 km N of Kolbeinsey Island near 68.15°N, 17.75°W along the Southern Kolbeinsey Ridge south of the Spar Fracture Zone (figures 1 and 2). Although the swarm started at 0456 (UTC), most of the 143 earthquakes registered occurred between 0830 and 1100, with events continuing until after 2300 (figure 3). Seismic activity on the southern segment of Kolbeinsey Ridge had been registered since 1 July 1999.

Figure (see Caption) Figure 1. Bathymetric relief map showing Iceland, the Kolbeinsey Ridge, and the earthquake swarm of 30 August 1999. Courtesy of the Icelandic Meteorological Office.
Figure (see Caption) Figure 2. Bathymetric map showing the 30 August 1999 earthquake swarm along the Southern Kolbeinsey Ridge south of the Spar Fracture Zone. Courtesy of the Icelandic Meteorological Office.
Figure (see Caption) Figure 3. Earthquakes from the Kolbeinsey Ridge swarm on 30 August 1999 plotted by time and magnitude. Courtesy of the Icelandic Meteorological Office.

Kolbeinsey Ridge is divided from Iceland by an oblique running transform fault, the Tjörnes Fracture Zone (TFZ). It is a slow-spreading ridge with an estimated asymmetric spreading of 10 mm/year. The ridge crest is nearly bare of sediments, although the bathymetry is very shallow. Kolbeinsey Ridge is cut by two major transform faults, the Spar Fracture Zone and the 70.8° Fracture Zone, and is thus divided into three segments, the Southern Kolbeinsey Ridge (SKR), the Northern Kolbeinsey Ridge (NKR), and the Central Kolbeinsey Ridge (CKR). The most active part of the ridge is the CKR north of the Spar Fracture Zone. Individual submarine volcanoes have not been named so far because the SIL registers events in detail only up to 300 km N of the Tjörnes Peninsula, covering just the southernmost segment of Kolbeinsey Ridge. Seismic events cluster along three lineaments in the region where the Tjörnes Fracture Zone cuts Kolbeinsey Ridge: the Grimsey lineament (east of Grimsey and N of the actual TFZ), the Husavik-Flatey fault (the actual TFZ), and the Dalvik lineament (cutting the Eyrarfjördur in half subparallel to the actual TFZ). This area is known for its hydrothermal fields made of anhydrite chimneys 200-400 m beneath sea level, which are detected along the seismic lineaments.

A submarine eruption was reported in 1372 on the Kolbeinsey Ridge NW of Grimsey Island at about 66.67°N, but the location is uncertain. Other reports of submarine eruptions N of Iceland have an even more uncertain location (1755) or have been discredited (1783 and 1838).

Further References. Kodaira, S., Mjelde, R., Gunnarsson, K., Shiobara, I., and Shimamura, H., 1997, Crustal structure of the Kolbeinsey Ridge, North Atlantic, obtained by use of ocean bottom, seismographs: JGR, v. 102, B2.

Rögnvaldsson, S.T., Gudmundsson, A., and Slunga, R., 1998, Seismotectonic analysis of the Tjörnes Fracture Zone, an active transform fault in north Iceland: JGR, v. 103, B12.

Information Contacts: Carsten Riedel, Christian-Albrechts-Universität, Kiel, Germany (Email: criedel@geophysik.uni-kiel.de, URL: http://www.geophysik.uni-kiel.de/criedel/kolbein/kolbe.htm); Icelandic Meteorological Office, Bustadavegur 9, 150 Reykjavík, Iceland (URL: http://www.vedur.is/).

The Global Volcanism Program has no Weekly Reports available for Kolbeinsey Ridge.

Bulletin Reports - Index


Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

10/1999 (BGVN 24:10) Submarine eruption or dike intrusion south of the Spar Fracture Zone




Information is preliminary and subject to change. All times are local (unless otherwise noted)


October 1999 (BGVN 24:10) Citation IconCite this Report


Submarine eruption or dike intrusion south of the Spar Fracture Zone

A submarine eruption or dike intrusion on 30 August 1999 was identified by seismic events from the Icelandic Seismological Network (SIL) at the Vedurstofa Islands. The swarm was centered ~180 km N of Grimsey and 100 km N of Kolbeinsey Island near 68.15°N, 17.75°W along the Southern Kolbeinsey Ridge south of the Spar Fracture Zone (figures 1 and 2). Although the swarm started at 0456 (UTC), most of the 143 earthquakes registered occurred between 0830 and 1100, with events continuing until after 2300 (figure 3). Seismic activity on the southern segment of Kolbeinsey Ridge had been registered since 1 July 1999.

Figure (see Caption) Figure 1. Bathymetric relief map showing Iceland, the Kolbeinsey Ridge, and the earthquake swarm of 30 August 1999. Courtesy of the Icelandic Meteorological Office.
Figure (see Caption) Figure 2. Bathymetric map showing the 30 August 1999 earthquake swarm along the Southern Kolbeinsey Ridge south of the Spar Fracture Zone. Courtesy of the Icelandic Meteorological Office.
Figure (see Caption) Figure 3. Earthquakes from the Kolbeinsey Ridge swarm on 30 August 1999 plotted by time and magnitude. Courtesy of the Icelandic Meteorological Office.

Kolbeinsey Ridge is divided from Iceland by an oblique running transform fault, the Tjörnes Fracture Zone (TFZ). It is a slow-spreading ridge with an estimated asymmetric spreading of 10 mm/year. The ridge crest is nearly bare of sediments, although the bathymetry is very shallow. Kolbeinsey Ridge is cut by two major transform faults, the Spar Fracture Zone and the 70.8° Fracture Zone, and is thus divided into three segments, the Southern Kolbeinsey Ridge (SKR), the Northern Kolbeinsey Ridge (NKR), and the Central Kolbeinsey Ridge (CKR). The most active part of the ridge is the CKR north of the Spar Fracture Zone. Individual submarine volcanoes have not been named so far because the SIL registers events in detail only up to 300 km N of the Tjörnes Peninsula, covering just the southernmost segment of Kolbeinsey Ridge. Seismic events cluster along three lineaments in the region where the Tjörnes Fracture Zone cuts Kolbeinsey Ridge: the Grimsey lineament (east of Grimsey and N of the actual TFZ), the Husavik-Flatey fault (the actual TFZ), and the Dalvik lineament (cutting the Eyrarfjördur in half subparallel to the actual TFZ). This area is known for its hydrothermal fields made of anhydrite chimneys 200-400 m beneath sea level, which are detected along the seismic lineaments.

A submarine eruption was reported in 1372 on the Kolbeinsey Ridge NW of Grimsey Island at about 66.67°N, but the location is uncertain. Other reports of submarine eruptions N of Iceland have an even more uncertain location (1755) or have been discredited (1783 and 1838).

Further References. Kodaira, S., Mjelde, R., Gunnarsson, K., Shiobara, I., and Shimamura, H., 1997, Crustal structure of the Kolbeinsey Ridge, North Atlantic, obtained by use of ocean bottom, seismographs: JGR, v. 102, B2.

Rögnvaldsson, S.T., Gudmundsson, A., and Slunga, R., 1998, Seismotectonic analysis of the Tjörnes Fracture Zone, an active transform fault in north Iceland: JGR, v. 103, B12.

Information Contacts: Carsten Riedel, Christian-Albrechts-Universität, Kiel, Germany (Email: criedel@geophysik.uni-kiel.de, URL: http://www.geophysik.uni-kiel.de/criedel/kolbein/kolbe.htm); Icelandic Meteorological Office, Bustadavegur 9, 150 Reykjavík, Iceland (URL: http://www.vedur.is/).

Eruptive History


Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).


Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
[ 1838 Jun 11 (?) ] [ Unknown ] Discredited    
[ 1783 ] [ Unknown ] Discredited    
1755 Sep 18 Unknown Confirmed   Unknown Volcano Uncertain: north of Iceland
1372 Unknown Confirmed 2 Historical Observations NW of Grimsey Island

The Global Volcanism Program has no synonyms or subfeatures listed for Kolbeinsey Ridge.

The Global Volcanism Program has no photographs available for Kolbeinsey Ridge.

Smithsonian Sample Collections Database


There are no samples for Kolbeinsey Ridge in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

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