Hekla

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  • Country
  • Subregion Name
  • Primary Volcano Type
  • Last Known Eruption
  • 63.98°N
  • 19.7°W

  • 1491 m
    4890 ft

  • 372070
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

27 March-2 April 2013

On 29 March the Icelandic Meteorological Office noted that Hekla had been quiet the previous few days; no additional earthquakes had been detected since a period of increased seismicity during 10-26 March. The Icelandic Civil Defense continued to maintain a level of "uncertainty".

Source: Icelandic Met Office



 Available Weekly Reports


2013: March


27 March-2 April 2013

On 29 March the Icelandic Meteorological Office noted that Hekla had been quiet the previous few days; no additional earthquakes had been detected since a period of increased seismicity during 10-26 March. The Icelandic Civil Defense continued to maintain a level of "uncertainty".

Source: Icelandic Met Office


20 March-26 March 2013

The Icelandic Meteorological Office noted that since 10 March, at least seven micro-earthquakes at Hekla, ranging in size from M 0.4 to 1, had been detected within a small area about 4.5 km NE of the summit, at depths of 11-12 km. These earthquakes were high-frequency, suggestive of brittle fracturing rather than magma movement. At Hekla, such a clustering of earthquakes is unusual in between eruptions. Continuous measurements of borehole strain and ground-based GPS showed no changes in crustal deformation.

On 26 March the Icelandic Meteorological Office increased the Aviation Colour Code from Green to Yellow, because of the increased seismic activity. Icelandic Civil Defense together with the Police in Hvolsvöllur had also declared a level of uncertainty for Hekla, although there were no observable signs that an eruption of Hekla was imminent.

Sources: Icelandic Met Office, Icelandic National Broadcasting Service (RUV)


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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
2000 Feb 26 2000 Mar 8 Confirmed 3 Historical Observations SW flank
1991 Jan 17 1991 Mar 11 Confirmed 3 Historical Observations Summit, SW, SE & NE flank fissures
1981 Apr 9 1981 Apr 16 Confirmed 2 Historical Observations Summit and north flank (900 and 740 m)
1980 Aug 17 1980 Aug 20 Confirmed 3 Historical Observations Summit, SW and NE flanks
1970 May 5 1970 Jul 5 Confirmed 3 Historical Observations Sudurgigar, Hlidargigar, Oldugigar
1947 Mar 29 1948 Apr 21 Confirmed 4 Historical Observations Hraungigur, Axlargigur, Toppgigur
1913 Apr 25 1913 May 18 Confirmed 2 Historical Observations E & NE of Hekla (Mundafit, Lambafit)
1878 Feb 27 1878 Apr Confirmed 2 Historical Observations East of Hekla (Krakagigar)
1845 Sep 2 1846 Apr 5 (?) Confirmed 4 Historical Observations Summit, SW and NE flanks
1766 Apr 5 1768 May Confirmed 4 Historical Observations Bjallagigar
1725 Apr 2 Unknown Confirmed 1 Historical Observations SW, south and east of Hekla
1693 Feb 13 1693 Sep 14 (?) Confirmed 4 Historical Observations
1636 May 8 1637 Jun Confirmed 3 Historical Observations
1597 Jan 3 1597 Jun (in or after) Confirmed 4 Historical Observations
1554 May 1554 Jun (?) Confirmed 2 Historical Observations SW of Hekla (Raudubjallar)
1510 Jul 25 Unknown Confirmed 4 Historical Observations
1440 (?) Unknown Confirmed   Tephrochronology SE of Hekla
1389 Dec 1 ± 30 days 1390 Confirmed 3 Historical Observations Summit ridge, west flank (Raudoldur)
1341 May 19 Unknown Confirmed 3 Historical Observations
1300 Jul 11 1301 Jul Confirmed 4 Historical Observations
1222 Unknown Confirmed 2 Historical Observations
1206 Dec 4 Unknown Confirmed 3 Historical Observations
1158 Jan 19 Unknown Confirmed 4 Historical Observations
1104 Oct 15 ± 45 days Unknown Confirmed 5 Historical Observations H1 tephra
1050 ± 500 years Unknown Confirmed   Tephrochronology Austurhraun
0800 ± 50 years Unknown Confirmed   Tephrochronology Heklutaglahraun
0750 (?) Unknown Confirmed   Tephrochronology Taglgigahraun, Solvahraun, Stakahraun
0650 ± 500 years Unknown Confirmed   Tephrochronology NE flank (Helliskvislarhraun)
0550 ± 1000 years Unknown Confirmed   Tephrochronology
0350 ± 1000 years Unknown Confirmed   Tephrochronology Vatnafjöll (Eskihlidarhraun)
0250 ± 1000 years Unknown Confirmed   Tephrochronology NE flank (Hestolduhraun), Vatnafjöll
0150 BCE ± 1000 years Unknown Confirmed   Tephrochronology Vatnafjöll (Kringluhraun)
0250 BCE ± 500 years Unknown Confirmed   Tephrochronology NE flank, Vatnafjöll (Langviuhraun)
0650 BCE ± 1000 years Unknown Confirmed   Tephrochronology Vatnafjöll (Svalaskardshraun)
0750 BCE ± 500 years Unknown Confirmed   Tephrochronology NE flank, Vatnafjöll (Langviuhraun)
0850 BCE ± 1000 years Unknown Confirmed   Tephrochronology NE flank (Raudkembingahraun), Vatnafjöll
1100 BCE ± 50 years Unknown Confirmed 5 Radiocarbon (corrected) H3 tephra
1150 BCE ± 1000 years Unknown Confirmed   Tephrochronology Vatnafjöll (Hraunhalsshraun)
1250 BCE ± 1000 years Unknown Confirmed   Tephrochronology NE flank, Vatnafjöll
1350 BCE ± 1000 years Unknown Confirmed   Tephrochronology Vatnafjöll
1550 BCE (?) Unknown Confirmed 4 Tephrochronology Seslund pumice
1650 BCE ± 1000 years Unknown Confirmed   Tephrochronology Vatnafjöll
1750 BCE ± 500 years Unknown Confirmed   Tephrochronology
1850 BCE ± 1000 years Unknown Confirmed   Tephrochronology NE flank (Krokagilsoduhraun), Vatnafjöll
2310 BCE ± 20 years Unknown Confirmed 5 Radiocarbon (corrected) H4 tephra
2450 BCE ± 1000 years Unknown Confirmed   Tephrochronology Vatnafjöll (Reynnisfellshraun)
2750 BCE ± 1000 years Unknown Confirmed   Tephrochronology Vatnafjöll
2950 BCE ± 500 years Unknown Confirmed   Tephrochronology Vatnafjöll (Tröllaskógahraun)
3350 BCE ± 1000 years Unknown Confirmed   Tephrochronology Raudkollar, Vatnafjöll (Grafellshraun)
3450 BCE ± 1000 years Unknown Confirmed   Tephrochronology Vatnafjöll
3750 BCE ± 1000 years Unknown Confirmed   Tephrochronology Vatnafjöll
3950 BCE ± 500 years Unknown Confirmed   Tephrochronology Axarhraun, Vatnafjöll
4050 BCE ± 500 years Unknown Confirmed   Tephrochronology Baejarhraun
4110 BCE ± 100 years Unknown Confirmed 5 Radiocarbon (corrected) Hekla Ö tephra
4150 BCE ± 1000 years Unknown Confirmed   Tephrochronology Vatnafjöll (Grasleysisfjallahraun)
4250 BCE ± 500 years Unknown Confirmed   Tephrochronology Knafaholdahraun
4350 BCE ± 1000 years Unknown Confirmed   Tephrochronology Vatnafjöll (Lambadalshraun)
4550 BCE ± 500 years Unknown Confirmed   Tephrochronology Krokahraun, Vatnafjöll
4650 BCE ± 500 years Unknown Confirmed   Tephrochronology Gunnarsholtshraun
4700 BCE (?) Unknown Confirmed 4 Tephrochronology Heka DH tephra
4750 BCE ± 1000 years Unknown Confirmed   Tephrochronology Vatnafjöll (west of Laufafell)
4950 BCE ± 1000 years Unknown Confirmed   Tephrochronology Vatnafjöll (Raudölduhraun)
5050 BCE ± 1000 years Unknown Confirmed   Tephrochronology Reydarvatnshraun lava flow, Vatnafjöll
5150 BCE (?) Unknown Confirmed 5 Radiocarbon (corrected) H5 tephra
5850 BCE ± 1000 years Unknown Confirmed   Tephrochronology Svinholdahraun

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. 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. Additional discussion of data sources can be found under Volcano Data Criteria.

Baldridge W S, McGretchin T R, Frey F A, 1973. Magmatic evolution of Heckla, Iceland. Contr Mineral Petr, 42: 245-258.

Green J, Short N M, 1971. Volcanic Landforms and Surface Features: a Photographic Atlas and Glossary. New York: Springer-Verlag, 519 p.

Gudmundsdottir E R, Larsen G, Eiriksson J, 2011. Two new Icelandic tephra markers: The Hekla Ö tephra layer, 6060 cal. yr BP, and Hekla DH tephra layer, ~6650 cal. yr BP. Land-sea correlation of mid-Holocene tephra markers. The Holocene, DOI: 10.1177/0959683610391313.

Gudmundsson A T, 1986b. Iceland-Fires. Reykjavik: Vaka-Helgafell, 168 p.

Gudmundsson M T, Larsen G, Hoskuldsson A, Gylfason A G, 2008. Volcanic hazards in Iceland. Jokull, 58: 251-268.

Hoskuldsson A, Oskarsson N, Pedersen R, Gronvold K, Vogfjord K, Olafsdottir R, 2007. The millennium eruption of Hekla in February 2000. Bull Volc, 70: 169-182.

Johannesson H, Jakobsson S P, Saemundsson K, 1982. Geological map of Iceland, sheet 6, south Iceland. Icelandic Museum Nat Hist & Iceland Geodetic Surv, 1:250,000 geol map, 2nd edition.

Johannesson H, Saemundsson K, 1998. Geological map of Iceland, 1:500,000. Tectonics. Icelandic Inst Nat Hist, Reykjavik.

Lacasse C, Karlsdottir S, Larsen G, Soosalu H, Rose W I, Ernst G G J, 2004. Weather radar observations of the Hekla 2000 eruption cloud, Iceland. Bull Volc, 66: 457-473.

Larsen G, Eriksson J, 2008. Holocene tephra archives and tephrochronology in Iceland - a brief overview. Jokull, 58: 229-250.

Larsen G, Thorarinsson S, 1977. H4 and other acid Hekla tephra layers. Jokull, 27: 1-19.

Sigmarsson O, Condomines M, Fourcade S, 1992. A detailed Th, Sr and O isotope study of Hekla: differentiation processes in an Icelandic Volcano. Contr Mineral Petr, 112: 20-34.

Soosalu H, Einarsson P, 2004. Seismic constraints on magma chambers at Hekla and Torfajokull volcanoes, Iceland. Bull Volc, 66: 276-286.

Soosalu H, Einarsson P, 1997. Seismicity around the Hekla and Torfajokull volcanoes, Iceland, during a volcanically quiet period, 1991-1995. Bull Volc, 59: 36-48.

Soosalu H, Einarsson P, 2002. Earthquake activity related to the 1991 eruption of the Hekla volcano, Iceland. Bull Volc, 63: 536-544.

Soosalu H, Einarsson P, Jakobsdottir S, 2003. Volcanic tremor related to the 1991 eruption of the Hekla volcano, Iceland. Bull Volc, 65: 562-577.

Soosalu H, Einarsson P, Thorbjarnadottir B S, 2005. Seismic activity related to the 2000 eruption of the Hekla volcano, Iceland. Bull Volc, 68: 21-36.

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

Thorarinsson S, 1967a. The Eruptions of Hekla in Historical Times. Reykjavik: Societas Scientiarum Islandica, p 1-183.

Thorarinsson S, Sigvaldason G E, 1972. The Hekla eruption of 1970. Bull Volc, 36: 269-288.

Thordarson T, Hoskuldsson A, 2008. Postglacial eruptions in Iceland. Jokull, 58: 197-228.

Tryggvason E, 1994. Observed ground deformation at Hekla, Iceland prior to and during the eruptions of 1970, 1980-81 and 1991. J Volc Geotherm Res, 61: 281-291.

Vilmundardottir E G, Hjartarson A, 1985. Pumice flows during Hekla eruptions. Natturufraedingurinn, 54: 17-30 (in Icelandic with English summary).

One of Iceland's most prominent and active volcanoes, Hekla lies near the southern end of the eastern rift zone. Hekla occupies a rift-transform junction, and has produced basaltic andesites, in contrast to the tholeiitic basalts typical of Icelandic rift zone volcanoes. Vatnafjöll, a 40-km-long, 9-km-wide group of basaltic fissures and crater rows immediately SE of Hekla forms a part of the Hekla-Vatnafjöll volcanic system. A 5.5-km-long fissure, Heklugjá, cuts across the 1491-m-high Hekla volcano and is often active along its full length during major eruptions. Repeated eruptions along this rift, which is oblique to most rifting structures in the eastern volcanic zone, are responsible for Hekla's elongated ENE-WSW profile. Frequent large silicic explosive eruptions during historical time have deposited tephra throughout Iceland, providing valuable time markers used to date eruptions from other Icelandic volcanoes. Hekla tephras are generally rich in fluorine and are consequently very hazardous to grazing animals. Extensive lava flows from historical eruptions, which date back to 1104 CE, cover much of the volcano's flanks.