Kolbeinsey Ridge

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  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 66.67°N
  • 18.5°W

  • 5 m
    16 ft

  • 375010
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Most Recent Bulletin Report: October 1999 (BGVN 24:10)


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 1. Bathymetric relief map showing Iceland, the Kolbeinsey Ridge, and the earthquake swarm of 30 August 1999. Courtesy of the Icelandic Meteorological Office.
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 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.

Index of Bulletin Reports


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




Bulletin Reports

All information contained in these reports is preliminary and subject to change.


10/1999 (BGVN 24:10) 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 1. Bathymetric relief map showing Iceland, the Kolbeinsey Ridge, and the earthquake swarm of 30 August 1999. Courtesy of the Icelandic Meteorological Office.
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 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/).
Download or Cite this Report

A submarine eruption was reported in 1372 near the Kolbeinsey Ridge NW of Grimsey Island. Kolbeinsey Island, the only subaerial expression of this portion of the Mid-Atlantic Ridge, is a small, rapidly eroding island that formed during the late-Pleistocene or Holocene. Dredged glass shards indicate submarine eruptive activity during the late-Pleistocene until at least 11,800 radiocarbon years ago. The island was 700 m long in 1616 CE, but had shrunk to 42 m long and 5 m high by 1985 and could be eroded below sea level in the early part of the 21st century. The Kolbeinsey Hydrothermal Field lies south of the island. Thorarinsson (1965) roughly plotted the location of the 1372 eruption at about 66 degrees 40 minutes North. Reidel et al. (2003) note that the location is uncertain, but could lie between the Kolbeinsey Ridge and Hóll Seamount. Other reports of submarine eruptions north of Iceland have an even more uncertain location (1755) or have been discredited (1783 and 1838).

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.

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title.

Berninghausen W H, 1964. A checklist of Icelandic volcanic activity. Bull Seism Soc Amer, 54: 443-450.

Botz R, Winckler G, Bayer R, Schmitt M, Schmidt M, Garbe-Schonberg D, Stoffers P, Kristjansson J K, 1999. Origin of trace gases in submarine hydrothermal vents of the Kolbeinsey Ridge, north Iceland. Earth Planet Sci Lett, 171: 83-93.

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior..

Lackschewitz K S, Dehn J, Wallrabe-Adams H-J, 1994. Volcaniclastic sediments from mid-oceanic Kolbeinsey Ridge, north of Iceland: evidence for submarine volcanic fragmentation processes. Geology, 22: 975-978.

Riedel C, Petersen T, Theilen F, Neben S, 2003. High b-values in the leaky segment of the Tjornes Fracture Zone north of Iceland: are they evidence for shallow magmatic heat sources?. J Volc Geotherm Res, 128: 15-29.

Saemundsson K, Hjartarson A, 1994. Geology and erosion of Kolbeinsey north of Iceland. In: Vigoson G (ed), {Proc Hornafjorlur Internat Coastal Symp, Reykjavik}, p 443-451.

Steinthorsson S, et al., 2002. Catalog of Active Volcanoes of the World - Iceland. Unpublished manuscript.

Thorarinsson S, 1965. Submarine eruptions near Iceland. Natturufraedingurinn, 35: 49-74 (in Icelandic with English summary).

Volcano Types

Submarine

Tectonic Setting

Rift zone
Oceanic crust (< 15 km)

Rock Types

Major
Basalt / Picro-Basalt

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
0
0
282
6,146

Affiliated Databases

Large Eruptions of Kolbeinsey Ridge Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).
WOVOdat WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.
EarthChem EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).
Smithsonian Collections Search the Smithsonian's NMNH Department of Mineral Sciences collections database. Go to the "Search Rocks and Ores" tab and use the Volcano Name drop-down to find samples.